@article{williams_pickworth_weaver_poole_2024, title={136 Evaluation of internal parasite burden in grazing beef cattle in North Carolina over a production lifecycle}, volume={102}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skae019.079}, abstractNote={
 Gastrointestinal nematode (GIN) parasite infections can be detrimental to not only cattle health and immunity, but also result in economic loss and poor performance. Cattle grazing in the southeast are challenged even further by the favorable environmental conditions for parasite development, especially those animals who have yet to develop an immunity to combat parasitism. To diminish potential economic and performance-based losses, many beef producers treat animals for GIN parasites with anthelmintics on a regular basis without proper diagnosis. Anthelmintic resistance(AR) develops when deworming products are overused and misused. To minimize the development of AR, selective deworming and sustainable management practices should be implemented. However, the severity of parasite burden over the production cycle needs to be better understood in beef cattle herds before recommendations can be made. Thus, the objective was to investigate the rates of GIN parasite infections through fecal egg counts (FEC) and the impact on body weight (BW) and body condition score (BCS). Angus-based cattle (6 mo-13 yr, n = 1,154) on a were utilized from five different research and educational herds across North Carolina. Cattle were categorized based on their age at the start of the project as either calves (n = 446), yearling heifers (n = 205), 2 year old (n = 260), 3-5 year old (n = 501), or 6+ year old (n = 206). Starting in September, FEC, BW, and BCS were collected and analyzed every 90 d at critical production timepoints (calving, breeding, weaning, and 90d post-weaning) to monitor the severity of GIN parasite challenge. Cattle on study were not treated with anthelmintics regardless of parasite load, with the exception of calves at four of the locations at the time of weaning. All data were analyzed using Proc MIXED in SAS with repeated measures. Statistical significance was declared at P ≤ 0.05 and a trend at 0.10 > P > 0.05. Age of cattle had an impact on FEC overall (P < 0.05), however, there was no difference between FEC of mature cattle over 3 yr (4.29 ± 4.9 eggs/gm). Calves had the greatest FEC (120.59 ± 4.2 eggs/gm) while cattle 6+ yr had the least (3.68 ± 4.5 eggs/gm). Cattle age at each location affected BCS and BW (P < 0.05). Between age groups across locations, time had an impact on FEC, BW, and BCS (P < 0.05). There was also a tendency (P = 0.6) for location to impact FEC. Calf sex did not affect (P > 0.05) FEC. Further FEC analysis of cattle under 2 yrof age is required to better understand when a natural immune response to GIN parasite infections develops.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Williams, Katherine G. and Pickworth, Carrie L. and Weaver, Andrew R. and Poole, Daniel H.}, year={2024}, month={Mar}, pages={67–68} }
 @article{rajo_williams_pickworth_foster_poole_2023, title={Exposure to Endophyte-Infected Tall Fescue Negatively Impacts Pulmonary Arterial Pressure in Beef Cattle}, volume={101}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skad068.077}, abstractNote={
 Fescue toxicosis negatively impacts cattle productivity. Previous data from our laboratory has demonstrated that cattle within a herd respond differently when grazing tall fescue, thus variation within a breed may provide genetic tolerance to the negative effects on performance. Fescue toxicosis results in major impacts on the cardiovascular system, thus it was hypothesized that exposure to ergot alkaloids negatively impacts pulmonary arterial pressure (PAP). The objective of this study was to examine changes in PAP and other production parameters in cattle consuming endophyte-infected tall fescue. Pregnant Angus cows (2 to 4 years; n = 65) were randomly divided to graze either endophyte-infected (EI) or novel endophyte (EN) pastures for4 consecutive weeks starting in April. Weekly measurements were collected to monitor physiological responses to consuming endophyte-infected tall fescue. In addition, PAP was measured every 4 weeks. Data were analyzed using a MIXED procedure of SAS, and statistical significance was determined at P < 0.05 and a tendency at 0.05 < P < 0.10, and evaluated the effects of treatment, age, week, and its interactions on BW, ADG, BCS, HCS, HSS and PAP. Exposure to EI did not affect BW, ADG, or BCS (P >0.05). Whereas, hair coat scores (1-5 scale) were significantly less for cattle consuming EN pastures (2.15 ± 0.05) compared with consuming EI pastures (2.31 ± 0.05; P < 0.05). Additionally, shedding scores (1-5 scale) were reduced in cattle consuming EN pastures (2.3±0.05) compared with consuming EI pastures (2.5±0.05; P< 0.05). There was a significant difference in PAP measurements in cattle exposed to EN pastures (37.16 ± 0.59 mm Hg) compared with EI pastures (31.31 ± 0.56 mm Hg; P < 0.0001). Additionally, PAP scores tended to deviate over the 14-week study between treatment groups (P = 0.0677). As expected, exposure to EI tall fescue resulted in greater HCS and HSS. However, the decrease in PAP in cattle consuming EI fescue was unexpected. Thus, further investigations are needed to examine the interaction between ergot alkaloid exposure on cardiovascular parameters such as PAP to potentially predict genetic differences in beef cattle to identify animals that would have a lower risk of developing fescue toxicosis.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Rajo, Edwin Benjamin and Williams, Katherine and Pickworth, Carrie L. and Foster, Derek and Poole, Daniel H.}, year={2023}, month={May} }
 @article{williams_rajo_weaver_poole_pickworth_2023, title={Impact of Fescue Variety on Fecal Egg Counts in Mature Beef Cattle}, volume={101}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skad068.093}, abstractNote={
 Fescue toxicosis decreases beef cattle performance in a multitude of ways, including decreased health and immunity. Cattle challenged by fescue toxicosis are often grazing in an environment favorable for development of gastrointestinal nematodes (GIN). Interactions of fescue toxicosis and parasite challenge may result in further performance and economic losses. Many beef producers treat animals regularly for GIN parasites with little insight on necessity or effectiveness of anthelmintic products. Overuse of anthelmintics can result in development of anthelmintic resistance in GIN populations. To minimize the development of anthelmintic resistance, implementation of selective deworming practices should be considered. However, level of parasite burden and effects of fescue toxicosis on parasite burden need to be better understood in beef cattle herds before recommendations can be offered. Therefore, the objective was to investigate the impact of fescue toxicosis on GIN parasite infection rates through fecal egg counts (FEC), body weight (BW), hematocrit (HCT), and body condition score (BCS). Starting in April, for 14 consecutive weeks post-weaning, pregnant Angus-based cows (2 to 4 years old, n = 65) were rotationally grazed on either novel endophyte (EN) fescue or endophyte-infected (EI) fescue pastures. Hematocrit, BCS, and BW were assessed weekly, while FEC were measured bi-weekly to monitor the physiological changes as a result of consuming endophyte-infected tall fescue. All data were analyzed using Proc MIXED in SAS with repeated measures. Statistical significance was declared at P ≤ 0.05 and a trend at 0.10 > P > 0.05. Overall, FEC were low (4.2 ± 0.9 eggs/gm) in these mature cattle and grazing EI or EN fescue did not have any overall effect (P > 0.05) on the FEC. However, FEC decreased (P < 0.05) over the course of the study from week 1 to week 13. Body weight, HCT, and BCS were not affected (P > 0.05) by the type of fescue grazed. There was a tendency (P < 0.10) for 2-3 and 4-6 year old cattle to have lower BW when grazing EI compared with EN fescue while cattle >7 were not affected. Cattle gained BW (P < 0.05) over the 14-week study (471.4 and 527.7 ± 0.6 kg, 0 and4 week respectively). For cattle grazing EI fescue, HCT linearly decreased (P < 0.05) from week 1 to week 14 whereas cattle grazing EN fescue had a linear increase (P < 0.05) in HCT from week 1 to week 14. More research is warranted to investigate beef cattle FEC and the potential impact of fescue type on FEC in younger beef cattle.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Williams, Katherine and Rajo, Edwin Benjamin and Weaver, Andrew R. and Poole, Daniel H. and Pickworth, Carrie L.}, year={2023}, month={May} }
 @article{freeman_poore_pickworth_alley_2021, title={Influence of weaning strategy on behavior, humoral indicators of stress, growth, and carcass characteristics}, volume={5}, ISSN={["2573-2102"]}, DOI={10.1093/tas/txaa231}, abstractNote={Abstract Weaning is one of the most stressful events a calf experiences in our current beef production system. Its effects may include reduced feed intake, increased activity, slower growth, and increased susceptibility to disease. This study was designed to evaluate weaning after a 7-d placement of nose flaps at 7 mo (N, n = 40) and delaying weaning by 49 d relative to 7-mo weaning (D, n = 39) as alternatives to the industry standard; abrupt weaning at 7 mo of age (A, n = 39). The 4-yr trial utilized Angus and Angus X Senepol steer calves. Calves were randomly assigned to weaning strategy after being stratified by dam parity (heifer/cow), hair coat phenotype (normal/slick), and body weight. Behavioral observations were made on five steers per strategy group per year over the weeks surrounding weaning. Activity levels were determined by accelerometers worn on neck collars. Blood samples were obtained from the observed cattle during the last 2 yr to determine haptoglobin and cortisol concentration. Once weaned, the steers were followed through finishing and carcass characteristics obtained at harvest. Twelve of 38 steers in the N group had sores in their nostrils from the nose flaps when the flaps were removed at weaning of A/N (237 ± 3 d of age). The A and D calves were more active than N calves in the first 2 to 3 d after weaning but settled down to similar activity levels to N by the day 4. The A and D groups were more vocal than N during the same time frame. Cortisol and haptoglobin remained within normal reference ranges. Average daily body weight gain (ADG) was greater for D than A, who in turn had greater ADG than N during the first 42 d after A and N calves were weaned (0.69, 0.54, and 0.37 kg/d for D, A, and N, respectively; P < 0.01). All treatment groups graded Low Choice at harvest and exhibited similar efficiency of gain during growth and finishing (P > 0.2). Based on ADG during the 42 d after weaning, we recommend delaying weaning when available pasture and cow body condition support this strategy. When conditions do not permit delayed weaning, abrupt weaning may be the next viable option based on animal welfare concerns and increased handling to place and remove the flaps. Nose flaps reduced vocalization at weaning but resulted in less postweaning ADG. Based on our data, we suggest that abrupt weaning under the conditions of this study, is less stressful than we perceive it to be, based on calf behavior.}, number={1}, journal={Translational Animal Science}, author={Freeman, S. and Poore, M. and Pickworth, C. and Alley, M.}, year={2021}, month={Jan}, pages={txaa231} }
 @article{alexander_pickworth_moore_poore_2020, title={102 Impact of weaning strategy on beef cow-calf behavior and activity}, volume={98}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz397.141}, DOI={10.1093/jas/skz397.141}, abstractNote={
 The objective of this study was to investigate the impact of three weaning strategies on cow and calf behavior and activity. Research has shown that weaning imposes stress on both the cow and the calf that can alter behavior, activity, and growth performance. Angus-based cow-calf pairs (n = 147) were randomly assigned to one of three treatment groups, abrupt weaning on d0 (Abrupt, n=50), fence-line contact for 7 days and then relocation of the cow on d7 (Fence, n=50), and late weaning by abrupt separation on d84 (Late, n = 47). Both cow and calf behaviors were observed over 7d prior to weaning and 7d post weaning activity for each treatment group. A single observer recorded activity and vocalizations for each animal twice in morning and evening on observation days. Calf activity was also continuously measured using accelerometers secured to collars worn by five calves per treatment group. Observation and activity data were analyzed using PROC MIXED of SAS. Significance was determined at P < 0.05 and a tendency at 0.05< P ≤0.10. The average activity units per day (AU/d) prior to weaning were similar among treatment groups. On d1 of weaning, Fence calves, who still had a visual contact with their dam, tended to have greater AU/d (P = 0.09) than the Abrupt calves and maintained a higher level of activity through d14 (P < 0.001). Late calves tended to have greater AU/d (P = 0.10) than Abrupt or Fence on d0-1 after their weaning. No difference in vocalizations (P = 0.41) by calves 7d post weaning were observed (1% Abrupt, 0% Fence, and 4% Late). More cows on Fence paced (1%) than Abrupt (0%) or Late (0%) (P < 0.05) in the 7d of fenceline contact. Late cows (2%) vocalized more than Abrupt (1%) or Fence (0%) when their calves were still with them (P < 0.05), but not after (P > 0.05) when no vocalizations were recorded. These results differ from the previous year study; therefore, further investigation of the impact of weaning strategy on cow-calf behavior and activity is warranted.}, number={Supplement_2}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Alexander, Molly and Pickworth, Carrie L and Moore, Mikayla and Poore, Matt H}, year={2020}, month={Nov}, pages={62–62} }
 @article{moore_cox-o'neill_poore_pickworth_2020, title={Impact of weaning strategy on beef cow and calf weight and body condition}, volume={98}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz397.192}, abstractNote={
 Weaning is one of the largest stressors in an animal’s life and can have long term impacts on the animal. The objective of this study was to investigate the effect of weaning strategy on the weight and body condition of beef cattle. A total of 249 Angus-based pairs at two locations were assigned to one of three treatments: abrupt removal of the calf on d0 (Abrupt, n = 84), fenceline contact for 7 days followed by complete separation on d7 (Fence, n = 85), or late weaning d84 (Late, n = 80). Weaned calves were supplemented 0.23 kg/hd/d of grain as fed while Late were not supplemented. Weights were obtained on d0, 7, 14, 28, 56, 84, 91, and 112. Body condition scores were recorded monthly. Data were analyzed using PROC MIXED of SAS and weights were analyzed with repeated measures. Significance was determined at P < 0.05. During the initial week post-abrupt weaning, Abrupt calves lost weight, Fence maintained weight, and Late calves gained weight (-0.4, 0, and 0.7 kg/d, respectively; P < 0.05). Over the complete weaning period (d0 to 112), Abrupt and Late weaned differed (P < 0.05) in their gains, while Fence was not different (P > 0.05) than either treatment (0.58, 0.64, and 0.62 kg/d, respectively). Cow overall ADG was not affected by weaning treatment (1.2, 0.8, and 0.5 kg/d, respectively; P >0.05). From d28 to 84, lactating Late cows gained less weight than Abrupt and Fence (0.3, 0.8, 0.8 kg/d, respectively; P < 0.0001). This contributed to a -0.1 BCS decrease at d112 for Late compared to a 0.3 and 0.2 BCS gain for Abrupt and Fence, respectively (P < 0.0001). Cows weaning calves after 10 mo of lactation were lighter than cows weaned after 7 mo; however, calves remaining with their dam maintained growth rates similar to grain supplemented weaned calves on pasture. While treatments influenced cow measures, all remained within normal values, therefore late weaning may be an option for producers to sell heavier calves without grain supplementation if marketing older calves.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Moore, Mikayla and Cox-O'Neill, Jordan and Poore, Matt H. and Pickworth, Carrie L.}, year={2020}, month={Nov}, pages={81–82} }
 @inproceedings{moore_cox-o’neill_poore_pickworth_2020, title={Impact of weaning strategy on beef cow and calf weight and body condition}, author={Moore, M.F. and Cox-O’Neill, J.L. and Poore, M.H. and Pickworth, C.L.}, year={2020} }
 @article{moore_cox-o'neill_poore_pickworth_2020, title={Impact of weaning strategy on beef cow and calf weight and body condition.}, volume={98}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz397.119}, abstractNote={
 Weaning is one of the largest stressors in an animal’s life and can have long term impacts on the animal. The objective of this study was to investigate the effect of weaning strategy on the weight and body condition of beef cattle. A total of 249 Angus-based pairs at two locations were assigned to one of three treatments: abrupt removal of the calf on d0 (Abrupt, n = 84), fenceline contact for 7 days followed by complete separation on d7 (Fence, n = 85), or late weaning d84 (Late, n = 80). Weaned calves were supplemented 0.23 kg/hd/d of grain as fed while Late were not supplemented. Weights were obtained on d0, 7, 14, 28, 56, 84, 91, and 112. Body condition scores were recorded monthly. Data were analyzed using PROC MIXED of SAS and weights were analyzed with repeated measures. Significance was determined at P < 0.05. During the initial week post-abrupt weaning, Abrupt calves lost weight, Fence maintained weight, and Late calves gained weight (-0.4, 0, and 0.7 kg/d, respectively; P < 0.05). Over the complete weaning period (d0 to 112), Abrupt and Late weaned differed (P < 0.05) in their gains, while Fence was not different (P >0.05) than either treatment (0.58, 0.64, and 0.62 kg/d, respectively). Cow overall ADG was not affected by weaning treatment (1.2, 0.8, and 0.5 kg/d, respectively; P > 0.05). From d28 to 84, lactating Late cows gained less weight than Abrupt and Fence (0.3, 0.8, 0.8 kg/d, respectively; P < 0.0001). This contributed to a -0.1 BCS decrease at d112 for Late compared to a 0.3 and 0.2 BCS gain for Abrupt and Fence, respectively (P < 0.0001). Cows weaning calves after 10 mo of lactation were lighter than cows weaned after 7 mo; however calves remaining with their dam maintained growth rates similar to grain supplemented weaned calves on pasture. While treatments influenced cow measures, all remained within normal values, therefore late weaning may be an option for producers to sell heavier calves without grain supplementation if marketing older calves.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Moore, Mikayla and Cox-O'Neill, Jordan and Poore, Matt H. and Pickworth, Carrie L.}, year={2020}, month={Nov}, pages={52–52} }
 @inproceedings{cox-o.'neill_valdez-nolasco_harmon_poore_eisemann_pickworth_2020, title={Nutritional Value of rye and purple top turnips for stocker cattle}, author={Cox-O.'Neill, J.L. and Valdez-Nolasco, C. and Harmon, D.D. and Poore, M.H. and Eisemann, J.H. and Pickworth, C.L.}, year={2020} }
 @inproceedings{cox-o’neill_valdez nolasco_franzluebbers_harmon_poore_eisemann_pickworth_2020, title={Nutritive value of a cereal rye monoculture and a cereal rye and turnip mix forage as part of an integrated crop-livestock system}, author={Cox-O’Neill, J. L. and Valdez Nolasco, C. and Franzluebbers, A.J. and Harmon, D.D. and Poore, M.H. and Eisemann, J.H. and Pickworth, C.L.}, year={2020} }
 @article{pickworth_sheffield_poole_2020, title={Pregnancy specific protein B concentration for the prediction of lambing rate in sheep}, volume={184}, ISSN={0921-4488}, url={http://dx.doi.org/10.1016/j.smallrumres.2020.106052}, DOI={10.1016/j.smallrumres.2020.106052}, abstractNote={An accurate diagnosis of pregnancy and prediction of lambing rates is a critical tool for improving efficiency in sheep flocks. The ability to manage ewe nutrition based on number of fetuses could improve animal welfare and productivity. Pregnancy Specific Protein B (PSPB) assays are commercially available and have proven a valuable tool for pregnancy diagnosis but less work has been done on accuracy of predicting fetal counts. The objective of this study was to determine if PSPB could be used to accurately predict lambing rates in sheep. Samples were collected from 54 Dorset, Katahdin, or crossbred ewes at 28 days post ram removal which was approximately 46 days post breeding. Samples were processed using the quantitative BioPRYN® assay. Ewes carrying twins had greater (P < 0.001) PSPB concentrations that ewes that delivered singles, and triplets or quads tended (P = 0.09) to be greater than twins. This test could become an effective diagnostic tool for improving sheep flock management throughout gestation by providing producers insight into predicting lambing rates.}, journal={Small Ruminant Research}, publisher={Elsevier BV}, author={Pickworth, Carrie L. and Sheffield, Julia and Poole, Rebecca K.}, year={2020}, month={Mar}, pages={106052} }
 @inproceedings{pickworth_2020, title={Randomizing multiple choice answers does not impact exam performance}, author={Pickworth, C.L.}, year={2020} }
 @inproceedings{west_cox-o’neill_harmon_poore_franzleubbers_eisemann_pickworth_2020, title={Rye with or without purple top turnips for stocker grazing as part of a Southeastern U.S. integrated crop-livestock system}, author={West, M.H. and Cox-O’Neill, J.L. and Harmon, D.D. and Poore, M.H. and Franzleubbers, A.J. and Eisemann, J.H. and Pickworth, C.L.}, year={2020} }
 @inproceedings{cox-o’neill_valdez-nolasco_harmon_poore_franzleubbers_eisemann_pickworth_2020, title={Subsequent corn yield and soil structure following grazing of annual forages in an integrated crop-livestock system}, author={Cox-O’Neill, J.L. and Valdez-Nolasco, C. and Harmon, D.D. and Poore, M.H. and Franzleubbers, A.J. and Eisemann, J.H. and Pickworth, C.L.}, year={2020} }
 @article{ott_freeman_poore_pickworth_2019, title={11 Impact of weaning strategy on calf performance, behavior, and activity}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz053.027}, DOI={10.1093/jas/skz053.027}, abstractNote={
 Weaning is known to be the most stressful time in a beef calf’s post-natal life. Weaning stress may have long-term impacts on cattle performance. This study was conducted to determine differences in calf stress under three weaning strategies. Two hundred twenty-nine Angus or Angus-Simmental cross pairs at two locations were assigned to one of three weaning treatments: abrupt removal of the calf on d 0 (Abrupt, n = 77), fenceline contact for 7 d prior to removal of the calf on d 7 (Fence, n = 79), and abrupt removal of the calf on d 84 (Late, n = 73). Behavioral observations were conducted pre- and post-weaning and total activity was measured prior to and after weaning using accelerometers placed on collars on five calves per treatment. Calf weights, hip heights, and body condition scores (BCS) were collected to evaluate calf performance post-weaning. Data were analyzed using PROC MIXED of SAS. Statistical significance was determined at P < 0.05 and a tendency at 0.05<p<0.10. Skeletal growth via hip height was not affected by weaning treatment. During the first 28 d after initial weaning, the Abrupt calves lost while the Late weaned calves gained weight (-0.09 and 0.49 kg/d, respectively; P < 0.05). Fence were intermediate weight and tended to be different from both treatments (0.02 kg/d; P = 0.09). Overall ADG was not affected (P > 0.10) by timing or strategy of weaning. Total activity was greater (P < 0.05) in Abrupt than Fence on d 1 and d 2 post-wean (Abrupt 26772 and 22346 and Fence 22235 and 16691 relative activity units/hour, respectively). Calf activity was elevated (P < 0.05) on day of weaning until d 2 post-wean then returned to pre-wean level by d 3 for all treatments. Short-term differences in calf performance warrant further exploration of the possible long-term effects on heifer development and steer feedlot performance.}, number={Supplement_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Ott, Grace C and Freeman, Sharon R and Poore, Matthew H and Pickworth, Carrie L}, year={2019}, month={Jul}, pages={12–13} }
 @article{brown_poole_jackson_poore_pickworth_poole_2019, title={111 Changes in proinflammatory cytokines and chemokines in beef steers chronically exposed to endophyte-infected tall fescue seed}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz053.095}, DOI={10.1093/jas/skz053.095}, abstractNote={
 Endophyte-infected tall fescue consumption adversely effects health and immune response. The aim of this study was to evaluate the impact of protein supplementation on cytokine response in steers consuming ergovaline, found in endophyte-infected tall fescue. Thirty-two beef steers were fed a total mixed ration (TMR) and randomly assigned to receive one of four treatments for 56 days: endophyte-free seed (0 ug/kg ergovaline) with either 18% (EF-18; n = 8) or 14% dietary protein (EF-14; n = 8) and endophyte-infected seed (500 ug/ kg ergovaline) with 18% (EI-18; n = 8) or 14% dietary protein (EI-14; n = 8). Blood samples were collected for cytokine analysis on d 28 and d 42 of the feeding period representing when steers vaccinated and boostered for bovine viral diarrhea (BVD) types 1 and 2 and infectious bovine rhinotracheitis (IBR). Cytokine concentrations were evaluated using Quantibody Bovine Cytokine Arrays. Data were analyzed using PROC MIXED of SAS with repeated measures. Statistical significance was determined at P0.05). Interestingly, concentrations of cytokines, IL13 (912±148 vs. 410.9±135 pg/mL) and IL21 (1636.0±295 vs. 629±305 pg/mL), which are involved in chronic inflammatory process were greater (P < 0.05) in EI steer compared to EF steers on d 28 and d 42. Concentrations of chemokine CCL4 and proinflammatory cytokines IFNG and IL-1alpha tended to be greater in EI steers compared to EF steers (P < 0.10). Overall, these data demonstrate that consumption of ergovaline increased proinflammatory cytokines and induced a chronic immune response. Developing a better understanding of overall immunity in cattle exposed to endophyte-infected tall fescue is fundamental to improve cattle health within the beef industry.}, number={Supplement_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Brown, Alecia R and Poole, Rebecca K and Jackson, McKenzie Lane and Poore, Matthew H and Pickworth, Carrie L and Poole, Daniel H}, year={2019}, month={Jul}, pages={42–43} }
 @article{ott_poole_poore_pickworth_2019, title={157 Impact of weaning strategy on heifer performance and reproductive development}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz258.314}, DOI={10.1093/jas/skz258.314}, abstractNote={
 Weaning is recognized as one of the most stressful times of a beef calf’s post-natal life. The objective of this study was to determine if weaning strategy impacts heifer development and reproduction. At 7 months of age, 96 predominantly Angus heifers at 2 locations were assigned to 1 of 3 weaning treatments: abrupt relocation of the calf on d0 (Abrupt, n = 32), fenceline contact starting on d0 prior to relocation of the calf on d7 (Fence, n = 33), and abrupt relocation of the calf on d84 (Late, n = 31). Calf weights, hip heights, and body condition scores (BCS) were collected to evaluate post-weaning performance. Reproductive tract scores (RTS; 0–5 scale, 5=most mature) were assigned every 54 days from d56 to d218. Heifers were synchronized using a 7-day CO-Synch + CIDR® protocol and artificially inseminated (AI) on d246. Data were analyzed using PROC MIXED of SAS with repeated measures. Statistical significance was determined at P ≤ 0.05. Late heifers were heavier at d28 and d56 than Abrupt and Fence (P < 0.05), but BW was similar across treatments starting at d84. Average daily gain (ADG) was greater for Late than Abrupt (0.39 and -0.03 kg/day respectively; P < 0.01) and tended to be greater than Fence (0.16 kg/day; P = 0.07) to d28; however, Late had lower ADG than Abrupt and Fence from d28-84 (0.66, 0.83, and 0.81 kg/day respectively; P < 0.05). No treatment differences were observed in BCS or hip height. Late tended to have greater RTS than Abrupt and Fence (2.54, 2.20, and 2.16 respectively; P ≤ 0.10) on d56, but there was no difference on or after d164. Fence tended to have greater AI conception rates than Abrupt and Late (66%, 44%, and 42% respectively; P ≤ 0.08). This data indicates there were initial performance differences based on weaning strategy, but this had minimal impact on heifer development.}, number={Supplement_3}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Ott, Grace C and Poole, Rebecca K and Poore, Matt H and Pickworth, Carrie L}, year={2019}, month={Dec}, pages={153–153} }
 @article{cox - o’neill_ott_harmon_poore_eisemann_pickworth_2019, title={256 Rye with or without purple top turnips for stocker calf grazing as part of a Southeastern U.S. integrated crop-livestock system}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz258.189}, DOI={10.1093/jas/skz258.189}, abstractNote={
 The objective was to evaluate stocker calf performance and grazing potential of double-crop annual forages during the winter as a diversified crop-livestock system. Angus crossbred steers (n = 56) were stratified by BW (275 ± 1.3 kg) and hip-height (118.3 ± 0.66 cm) into 12 groups (n = 4 to 6/group) and randomly assigned to graze either monoculture rye (RYE) or rye and turnip mixture (MIX). The study was conducted at two locations in eastern North Carolina. Each treatment had 3 replicate pastures (6 to 9 ha) per location with a stocking rate of 0.6 ha/steer. Winter annual treatments were planted following corn grain harvest in early October, with the MIX producing 64% ± 2.9% rye and 36% ± 2.0% turnip (leaf and root) on a DM basis. Two-day consecutive weights of steers were taken at initiation and completion of the grazing period. Mineral and water were available ad libitum. Data were analyzed using Mixed Procedure of SAS and differences were declared at P < 0.05, with tendencies declared between P = 0.05 and 0.10. Initial forage mass was greater (P < 0.05) for MIX (1889 kg DM/ha; 9.4% turnip root) than RYE (1568 kg DM/ha). All steers at a location were removed from grazing when forage mass was estimated at 1200 kg DM/ha. The grazing period was 45 days for location 1 and 77 days for location 2. Values for steers grazing RYE and MIX, respectively, for the following variables did not differ (P > 0.10): free choice mineral intake, 201 g/d and 216 g/d; ADG 0.99 kg/d and 1.05 kg/d; gain per hectare 104 kg/ha and 110 kg/ha; and hip-height growth 8.9 cm and 8.1 cm. The increased forage availability for the MIX did not result in greater ADG or gain per hectare when stocking rate and grazing period remained constant.}, number={Supplement_3}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Cox - O’Neill, Jordan L and Ott, Grace C and Harmon, Deidre D and Poore, Matt H and Eisemann, Joan H and Pickworth, Carrie L}, year={2019}, month={Dec}, pages={91–92} }
 @article{davis_poole_poore_poole_pickworth_2019, title={47 Interaction of dietary protein and endophyte- infected Tall Fescue seed in stocker steers on finishing phase performance and carcass traits}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz053.189}, DOI={10.1093/jas/skz053.189}, abstractNote={
 Fescue toxicosis is a multifaceted disease that negatively impacts cattle. It was hypothesized that exposure to endophyte-infected fescue during the stocker phase affects finishing phase growth and carcass characteristics. Eight-month-old steers were sorted by weight and randomly assigned to receive one of four treatments for 56 days in confinement: endophyte-free seed (0 ug/kg ergovaline) with either 18% (EF-18; n = 9) or 14% dietary protein (EF-14; n = 9) and endophyte-infected seed (500 ug/kg ergovaline) with 18% (EI-18; n = 9) or 14% dietary protein (EI-14; n = 9). Following fescue exposure calves were backgrounded on novel endophyte fescue pastures for 8 mo. At 18 mo, all steers were vaccinated, implanted, and reentered the feedlot for a 112 d growing phase and 52 d finishing phase. Body weight was recorded every 28 d and carcass data was collected at slaughter. Data were analyzed using the MIXED procedure of SAS for effects of BW, ADG, dressing percentage (DP), HCW, backfat, ribeye area (REA), KPH, USDA Yield grade (YG), and USDA Quality grade (QG). Statistical significance was determined at P > 0.05) HCW, BW, backfat, REA, DP, or QG. TheEI-14 had a greater ADG (1.69 kg/d) during the feedlot growing phase compared to the other treatment groups (1.53, 1.47, 1.55 for EI-18, EF-14, EF-18, respectively; P > 0.05). Steers stockered on 18% dietary protein had greater BW compared to steers previously fed at 14% (501.3±3.8 vs. 489.7±3.8; P = 0.0339). In addition, 18% protein in stocker diet resulted in greater KPH (2.3±0.2 vs. 1.78±0.2; P = 0.0129) and YG (3.4±0.1 vs. 3.0±0.1; P = 0.0168) compared with steers fed 14% dietary protein. Finishing growth and carcass characteristics were not affected by exposure to ergot alkaloids at weaning as much as dietary protein when cattle had a background period prior to feedlot entry}, number={Supplement_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Davis, Matthew E and Poole, Rebecca K and Poore, Matthew H and Poole, Daniel H and Pickworth, Carrie L}, year={2019}, month={Jul}, pages={83–83} }
 @article{worthington_ott_poore_pickworth_2019, title={57 Impact of weaning strategy on beef cow performance}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz053.000}, DOI={10.1093/jas/skz053.000}, abstractNote={
 It has been shown that physiologic stress in beef cattle can impact animal performance. Weaning stress is recognized as a major stress in a calf’s life. However, less is known of its impacts on the dam or developing fetus, as the dam is at the end of the second trimester at weaning. Therefore, the objective was to investigate the impact of weaning stress on cow performance. A total of 240 cows from two locations were assigned to one of three weaning strategies: abrupt removal of the calf on d 0 (n = 80), d 7 cow-calf fenceline contact (n = 81), and late weaning on d 84 (n = 79). Cows averaged 16 and 24 weeks of gestation on d 0 and d 84 respectively. Weights and BCS were obtained monthly. Behavioral observations occurred over the week before and after weaning for each weaning period. Five late-wean cows per location were milked on d 14 and d 70 to estimate milk yield throughout the late wean period. Data were analyzed using the MIXED procedure of SAS with BW and BCS utilizing repeated measures. Means are declared different at P ≤ 0.05. The ADG over the course of the study was lower (P < 0.05) for the late weaned cows compared to the abrupt weaned cows. This was also reflected by change in body condition where late weaned cows dropped from a 5.7 to a 4.9 (P < 0.05) over the 105 d. Milk production in late weaned cows decreased over time (6.0 and 4.4 kg/d for d 14 and 70, respectively; P = 0.05). Energy expenditure for lactation may have contributed to the drop in BCS of the late weaned compared with the non-lactating cows and could compromise third trimester growth of calf in utero. The results of this study warrant further exploration of the effect of weaning stress on dams and their developing fetuses.}, number={Supplement_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Worthington, Mary Clarke and Ott, Grace C and Poore, Matthew H and Pickworth, Carrie L}, year={2019}, month={Jul}, pages={1–1} }
 @misc{pickworth_2019, title={Animal agriculture in a sustainable food supply}, author={Pickworth, C.L.}, year={2019} }
 @article{spears_lloyd_pickworth_huang_krafka_hyda_grimes_2019, title={Chromium propionate in broilers: human food and broiler safety}, volume={98}, ISSN={0032-5791}, url={http://dx.doi.org/10.3382/ps/pez444}, DOI={10.3382/ps/pez444}, abstractNote={Chromium propionate (Cr Prop) is approved by the U.S. Food and Drug Administration Center for Veterinary Medicine for supplementation to broiler diets up to 0.20 mg Cr/kg diet. A 49-D study was conducted to: 1) determine the safety of Cr Prop when supplemented at 2 and 10 times (×) the approved feeding level over the normal life span of broilers, and 2) determine the effects of supplementing Cr Prop on Cr concentrations of tissues consumed by humans. On day zero, 216 Ross 708 broilers were stratified by weight within sex and randomly assigned to treatments. Dietary treatments were 0 (control), 0.40, and 2.0 mg supplemental Cr/kg diet from Cr Prop. There were 6 replicate cages each of male and female broilers per treatment. At the end of the study blood was collected for determination of plasma biochemical measurements and tissue samples were collected for Cr analysis. Supplementing 0.40 mg Cr/kg diet (2×) did not adversely affect broiler performance, mortality, plasma biochemical measurements or Cr concentrations in breast muscle, skin with adhering fat, or liver. Chromium propionate supplemented at 2.0 mg Cr/kg (10×) did not affect Cr concentrations in breast muscle or skin with adhering fat, but increased (P < 0.05) liver Cr concentrations. Supplementing Cr Prop at 10× the approved feeding level decreased feed intake and gain in male but not female broilers from days 21 to 49. Results of this study support the safety of Cr Prop in broiler diets, and indicate that Cr Prop supplementation to broiler diets at 2 or 10× the approved feeding level does not present a human health concern.}, number={12}, journal={Poultry Science}, publisher={Elsevier BV}, author={Spears, J.W. and Lloyd, K.E. and Pickworth, C.A. and Huang, Y.L. and Krafka, K. and Hyda, J. and Grimes, J.L.}, year={2019}, month={Dec}, pages={6579–6585} }
 @article{poole_womble_poore_poole_pickworth_2019, title={Effects of endophyte-infected tall fescue seed and protein supplementation on stocker steers: I. Growth performance and hemodynamic responses}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz249}, DOI={10.1093/jas/skz249}, abstractNote={Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue and is detrimental to growth and performance. Recent research has shown that supplementing protein has the potential to enhance growth performance in weaned steers. Therefore, the objective of this study was to evaluate the effect of supplemental crude protein (CP) on physiological parameters in stocker steers experiencing fescue toxicosis. Thirty-six weaned Angus steers (6 mo. of age) stratified by weight (196.1 ± 3.6 kg) were assigned to a 2 ✕ 2 factorial arrangement for 56d: endophyte-free (EF) seed and 14% CP (EF-14; n=9), EF seed and 18% CP (EF-18; n=9), endophyte-infected (EI) seed and 14% CP (EI-14; n=9), and EI seed and 18% CP (EI-18; n=9). Steer growth and hemodynamic responses were collected weekly during ergot alkaloid exposure. On d 14 of the trial, iButton® temperature data loggers were subcutaneously inserted in the lateral neck region to record hourly body temperature for 42 d. Data were analyzed using PROC MIXED of SAS with repeated measures. No differences were observed in DMI, BW, ADG, F:G, or BCS during the treatment period (P > 0.05). Hair shedding scores, rectal temperatures, surface temperatures, and respiration rates were greater in EI steers compared to EF steers regardless of supplemental CP (P < 0.05). However, subcutaneous body temperature was greater in EI-14 steers (37.94°C) compared to other steer groups (37.60, 37.68, 37.72 ± 0.04°C for EF-14, EF-18, and EI-18, respectively; P < 0.05). Prolactin concentrations tended to be greater in EF steers when compared to EI steers (P = 0.07). Heart rate and hematocrit was reduced for EI-18 steers compared to other steer groups (P < 0.05). Caudal artery diameter was reduced in EI-18 steers compared to EI-14 steers (2.60 vs. 2.75 ± 0.05 mm, respectively; P < 0.05) and caudal vein diameter was reduced in EI-18 steers (3.20 mm) compared to all other steer groups (3.36, 3.39, 3.50 mm for EF-14, EF-18, and EI-14, respectively; P < 0.05). However, there was no difference observed in systolic or diastolic blood pressure during the treatment period (P > 0.05). Based on the data, exposure to low to moderate levels of ergot alkaloids during the stocker phase had a negative impact on hemodynamic responses and supplemental CP had minimal impact to alleviate symptoms. Therefore, feeding additional protein above established requirements is not expected to help alleviate fescue toxicosis.}, number={9}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Poole, Rebecca K and Womble, Carrisa M and Poore, Matthew H and Poole, Daniel H and Pickworth, Carrie L}, year={2019}, month={Jul}, pages={3776–3785} }
 @article{poole_brown_poore_pickworth_poole_2019, title={Effects of endophyte-infected tall fescue seed and protein supplementation on stocker steers: II. Adaptive and innate immune function}, volume={97}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/skz250}, DOI={10.1093/jas/skz250}, abstractNote={Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue that affects performance; however little information is available pertaining to its effects on immunity. Recently, it has been shown that supplemental crude protein (CP) can improve performance in weaned steers post-vaccination. Thus, the objective of this study was to evaluate the effect of supplemental CP on innate and adaptive immune responses in stocker steers chronically exposed to ergovaline. Angus steers (n = 12 pens; 3 steers/pen) were stratified by weight and assigned to a 2 x 2 factorial arrangement to examine crude protein levels of supplement (14% or 18%) and ergovaline exposure (0 or 185 μg ergovaline/kg BW/d via ground endophyte-free (EF) or endophyte-infected (EI) tall fescue seed, respectively) on immune response. Consumption of low to moderate concentration of ergovaline from EI tall fescue seed was sufficient to induce mild symptoms associated with fescue toxicosis. Blood samples were collected at d 0, 42, and 56 to evaluate infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea virus (BVDV) type 1b titers following vaccine challenge. Additionally, serum cytokine concentrations were evaluated using Quantibody® Bovine Cytokine Arrays on d 0, 28, and 42. Data were analyzed using PROC MIXED of SAS with repeated measures. Regardless of treatment, no differences were observed in IBR and BVDV-1b seroconversion following vaccine challenge (P > 0.05). Regardless of crude protein concentration, EI steers had greater concentrations of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1α), chemokines (CCL2, CCL4, MIG), anti-inflammatory cytokines (IL-2, -13, -15, -21), and various growth factors (FGF-1, IGF-1, VEGF-A) when compared to EF steers (P < 0.05). Furthermore, VEGF-A and IGF-1 concentrations were greater in EI-14 steers on d 28 compared to EI-18, EF-14 and EF-18 steers (P < 0.05), however this difference was not observed on d 0 or 42 (P > 0.05). Based on these data, steers exposed to ergovaline have an increase in pro- and anti-inflammatory cytokines and supplemental CP had minimal impact to mitigate this response. However, in the current study exposure to ergovaline had little to no effect on adaptive immunity and response to vaccination. Together, chronic exposure to ergovaline results in a hyperactive innate immune response, which may lead to an immuno-compromised animal.}, number={10}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Poole, Rebecca K and Brown, Alecia R and Poore, Matthew H and Pickworth, Carrie L and Poole, Daniel H}, year={2019}, month={Jul}, pages={4160–4170} }
 @inproceedings{poole_brown_jackson haimon_pickworth_poore_2019, title={Impact of Fescue toxicosis on the success of reproductive technologies}, author={Poole, D.H. and Brown, A.R. and Jackson Haimon, M.L. and Pickworth, C.L. and Poore, M.H.}, year={2019} }
 @inproceedings{worthington_ott_poore_pickworth_2019, title={Impact of weaning strategy on beef cow performance}, author={Worthington, M.C. and Ott, G.C. and Poore, M.H. and Pickworth, C.L.}, year={2019} }
 @article{worthington_ott_poore_pickworth_2019, title={Impact of weaning strategy on beef cow performance.}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz053.190}, abstractNote={
 It has been shown that physiologic stress in beef cattle can impact animal performance. Weaning stress is recognized as a major stress in a calf’s life. However, less is known of its impacts on the dam or developing fetus, as the dam is at the end of the second trimester at weaning. Therefore, the objective was to investigate the impact of weaning stress on cow performance. A total of 240 cows from two locations were assigned to one of three weaning strategies: abrupt removal of the calf on d 0 (n = 80), d 7 cow-calf fenceline contact (n = 81), and late weaning on d 84 (n = 79). Cows averaged 16 and 24 weeks of gestation on d 0 and d 84 respectively. Weights and BCS were obtained monthly. Behavioral observations occurred over the week before and after weaning for each weaning period. Five late-wean cows per location were milked on d 14 and d 70 to estimate milk yield throughout the late wean period. Data were analyzed using the MIXED procedure of SAS with BW and BCS utilizing repeated measures. Means are declared different at P ≤ 0.05. The ADG over the course of the study was lower (P < 0.05) for the late weaned cows compared to the abrupt weaned cows. This was also reflected by change in body condition where late weaned cows dropped from a 5.7 to a 4.9 (P < 0.05) over the 105 d. Milk production in late weaned cows decreased over time (6.0 and 4.4 kg/d for d 14 and 70, respectively; P = 0.05). Energy expenditure for lactation may have contributed to the drop in BCS of the late weaned compared with the non-lactating cows and could compromise third trimester growth of calf in utero. The results of this study warrant further exploration of the effect of weaning stress on dams and their developing fetuses.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Worthington, Mary Clarke and Ott, Grace C. and Poore, Matthew H. and Pickworth, Carrie L.}, year={2019}, month={Jul}, pages={83–83} }
 @inproceedings{ott_freeman_poore_pickworth_2019, title={Impact of weaning strategy on calf performance, behavior, and activity}, author={Ott, G.C. and Freeman, S.R. and Poore, M.H. and Pickworth, C.L.}, year={2019} }
 @article{ott_freeman_poore_pickworth_2019, title={Impact of weaning strategy on calf performance, behavior, and activity.}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz053.152}, abstractNote={
 Weaning is known to be the most stressful time in a beef calf’s post-natal life. Weaning stress may have long-term impacts on cattle performance. This study was conducted to determine differences in calf stress under three weaning strategies. Two hundred twenty-nine Angus or Angus-Simmental cross pairs at two locations were assigned to one of three weaning treatments: abrupt removal of the calf on d 0 (Abrupt, n = 77), fenceline contact for 7 d prior to removal of the calf on d 7 (Fence, n = 79), and abrupt removal of the calf on d 84 (Late, n = 73). Behavioral observations were conducted pre- and post-weaning, and total activity was measured prior to and after weaning using accelerometers placed on collars on five calves per treatment. Calf weights, hip heights, and body condition scores (BCS) were collected to evaluate calf performance post-weaning. Data were analyzed using PROC MIXED of SAS. Statistical significance was determined at P < 0.05 and a tendency at 0.05 0.10) by timing or strategy of weaning. Total activity was greater (P < 0.05) in Abrupt than Fence on d 1 and d 2 post-wean (Abrupt 26772 and 22346 and Fence 22235 and 16691 relative activity units/hour, respectively). Calf activity was elevated (P < 0.05) on day of weaning until d 2 post-wean then returned to pre-wean level by d 3 for all treatments. Short-term differences in calf performance warrant further exploration of the possible long-term effects on heifer development and steer feedlot performance.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Ott, Grace C. and Freeman, Sharon R. and Poore, Matthew H. and Pickworth, Carrie L.}, year={2019}, month={Jul}, pages={67–68} }
 @inproceedings{davis_poole_poore_poole_pickworth_2019, title={Interaction of dietary protein and endophyte-infected Tall Fescue seed in stocker steers on finishing phase performance and carcass traits}, author={Davis, M.E. and Poole, R.K. and Poore, M.H. and Poole, D.H. and Pickworth, C.L.}, year={2019} }
 @article{davis_poole_poore_poole_pickworth_2019, title={Interaction of dietary protein and endophyte-infected Tall Fescue seed in stocker steers on finishing phase performance and carcass traits.}, volume={97}, ISBN={1525-3163}, DOI={10.1093/jas/skz053.086}, abstractNote={
 Fescue toxicosis is a multifaceted disease that negatively impacts cattle. It was hypothesized that exposure to endophyte-infected fescue during the stocker phase affects finishing phase growth and carcass characteristics. Eight-month-old steers were sorted by weight and randomly assigned to receive one of four treatments for 56 days in confinement: endophyte-free seed (0 ug/ kg ergovaline) with either 18% (EF-18; n = 9) or 14% dietary protein (EF-14; n = 9) and endophyte-infected seed (500 ug/kg ergovaline) with 18% (EI-18; n = 9) or 14% dietary protein (EI-14; n = 9). Following fescue exposure calves were backgrounded on novel endophyte fescue pastures for 8 mo. At 18 mo, all steers were vaccinated, implanted, and reentered the feedlot for a 112 d growing phase and 52 d finishing phase. Body weight was recorded every 28 d and carcass data was collected at slaughter. Data were analyzed using the MIXED procedure of SAS for effects of BW, ADG, dressing percentage (DP), HCW, backfat, ribeye area (REA), KPH, USDA Yield grade (YG), and USDA Quality grade (QG). Statistical significance was determined at P > 0.05) HCW, BW, backfat, REA, DP, or QG. TheEI-14 had a greater ADG (1.69 kg/d) during the feedlot growing phase compared to the other treatment groups (1.53, 1.47, 1.55 for EI-18, EF-14, EF-18, respectively; P > 0.05). Steers stockered on 18% dietary protein had greater BW compared to steers previously fed at 14% (501.3±3.8 vs. 489.7±3.8; P = 0.0339). In addition, 18% protein in stocker diet resulted in greater KPH (2.3±0.2 vs. 1.78±0.2; P = 0.0129) and YG (3.4±0.1 vs. 3.0±0.1; P = 0.0168) compared with steers fed 14% dietary protein. Finishing growth and carcass characteristics were not affected by exposure to ergot alkaloids at weaning as much as dietary protein when cattle had a background period prior to feedlot entry}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Davis, Matthew E. and Poole, Rebecca K. and Poore, Matthew H. and Poole, Daniel H. and Pickworth, Carrie L.}, year={2019}, month={Jul}, pages={38–38} }
 @inproceedings{cox-o'neill_ott_harmon_poore_eisemann_pickworth_2019, title={Rye with or without purple top turnips for stocker calf grazing as part of a Southeastern U.S. integrated crop-livestock system}, author={Cox-O'Neill, J.L. and Ott, G.C. and Harmon, D.D. and Poore, M.H. and Eisemann, J.H. and Pickworth, C.L.}, year={2019} }
 @article{womble_poole_poole_pickworth_2018, title={142 Impact of Protein Supplementation on Physiological Response of Steers Consuming Endophyte-Infected Tall Fescue Seed.}, volume={96}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/sky027.142}, DOI={10.1093/jas/sky027.142}, abstractNote={Fescue toxicosis in beef cattle is caused by consumption of ergot alkaloids produced by endophyte-infected tall fescue and results in chronic decreases in productivity and growth performance. It was hypothesized that protein supplementation may have a positive effect on the physiological responses of growing steers consuming ergot alkaloids. In this study, 36 weaned steers (196.1 ± 3.6 kg) were used in a 2 x 2 factorial arrangement of treatments to evaluate physiological responses to chronic exposure to ergot alkaloids via fescue seed and dietary protein. Steers were blocked by weight and randomly assigned to one of four treatment groups for 56 d: endophyte-free seed diet (0 ppm ergovaline) with 14% CP (EF-14), endophyte-free seed diet with 18% CP (EF-18), endophyte-infected seed diet (500 ppm ergovaline) with 14% CP (EI-14), and endophyte-infected seed diet with 18% CP (EI-18). Steers were fed at a calculated rate of 2.35% BW to achieve similar intake among treatment groups. Weekly physiological measurements were collected to evaluate the steers’ responses to the diets. On d 14, iButton temperature data loggers were subcutaneously inserted in the lateral neck region to record hourly body temperature. Steers received the bovine viral diarrhea types 1 and 2 and infectious bovine rhinotracheitis vaccines on d 28, then were administered booster vaccines on d 42. Data were analyzed using the MIXED procedure in SAS with repeated measures. Statistical significance was determined at P < 0.05 and a tendency at 0.05 < P < 0.10. The DMI expressed as % BW and kg per day was uniform across treatments. No differences were observed in BCS, BW, and ADG among treatment groups. However, the EI-14 steers had a less efficient F:G ratio compared to other treatment groups (6.18, 5.6, 5.7, 5.5 for EI-14, EI-18, EF-14, EF-18, respectively; P < 0.05). In contrast to previous studies, hair coat score and hair coat shedding score were not different among treatment groups (P > 0.05). The EI-18 steers had a lower heart rate compared to other groups (88.0, 98.0, 93.2, 94.8 beats per minute for EI-18, EI-14, EF-14, EF-18, respectively; P < 0.05). Meanwhile, EI steers had higher rectal temperatures and respiratory rates starting on d 35 of the feeding period compared to EF steers (P < 0.05). Diurnal rhythms in subcutaneous body temperatures varied among treatment groups throughout the feeding period (P < 0.05). Overall, physiological responses to fescue toxicosis were minimal in the growing steers.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Womble, C M and Poole, R K and Poole, D H and Pickworth, C L}, year={2018}, month={Mar}, pages={75–76} }
 @article{sheffield_roman_roper_poole_pickworth_2018, title={143 Flushing and Synchronization Protocol Impacts on out of Season Breeding in Ewes.}, volume={96}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/sky027.143}, DOI={10.1093/jas/sky027.143}, abstractNote={Ewes with low BCS (2 on scale of 5) have reduced fertility and decreased conception rates compared to ewes in more ideal BCS (3 to 4). Providing ewes with low BCS an increased feeding rate prior to breeding may help improve BCS and increase fertility and conception rates. The primary objective of the study was to determine if an increased feeding rate of low BCS ewes prior to breeding would improve conception rates and number of lambs conceived. The secondary objective of the study was to determine if extending the length of time of progesterone exposure via 10, 12, or 14 d controlled intravaginal drug releaser (CIDR) during estrus synchronization impacts ewe fertility. The 46 Dorset and Katahdin based crossbred ewes were used in an out-of-season breeding study. The ewes were allocated to 2 treatments: LOW BCS and HIGH BCS (2.09 and 2.55, respectively). Ewes were maintained on pasture and fed a grain-based flushing supplement based on treatment (0.17 kg HIGH and 0.35 kg LOW per ewe a day, respectively) for 42 d. Ewes in each treatment were divided into 4 breeding groups based on breed. On d 42 ewes began an estrus synchronization followed by natural mating. At breeding the mean BCS were 2.7 LOW and 2.9 HIGH (P > 0.10). All rams were fitted with marking harnesses and marks were recorded daily for 42 d. At d 45 post ram removal, ultrasonography was used to determine the pregnancy rate and estimate fetal counts. The data set was analyzed in Proc MIXED of SAS to determine effects of flushing treatment and synchronization protocol. Means were determined to be significant at P < 0.05 and trends at 0.05 < P < 0.10. The conception rates were not affected by BCS at 72.2% for LOW and 71.4% for HIGH (P > 0.10). Fetal counts, however, tended to be lower in LOW compared to HIGH ewes (1.8 and 2.1 ± 0.15, respectively; P = 0.07). It was determined that extended progesterone exposure did not impact conception rates (73, 77, and 64% for 10, 12, and 14 d, respectively; P > 0.10). In addition, fetal counts were similar across synchronization protocols (1.9, 2.0, and 1.9 for 10, 12, and 14 d, respectively; P > 0.10). During out-of-season breeding, using an increased flushing feeding rate in low BCS ewes in conjunction with varying CIDR insertion time during natural mating can promote ewe fertility.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Sheffield, J and Roman, C and Roper, B L and Poole, R K and Pickworth, C L}, year={2018}, month={Mar}, pages={76–76} }
 @article{pickworth_2018, title={2 Developing future animal science students through a residential summer camp program.}, volume={96}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/sky404.1086}, DOI={10.1093/jas/sky404.1086}, abstractNote={Animal Science programs have observed a shift in student enrollment from rural males with agricultural interest to urban females interested in veterinary science which has resulted in a decline in students seeking livestock oriented careers. Summer camps are an important part of the educational process and offer an opportunity to explore new areas. In review of summer camps available in the animal disciplines it was discovered that there were no camp programs available to explore the diversity of opportunities available with livestock science. Instead a plethora of camps focused on veterinary medicine, livestock fitting and showing, or judging. Therefore our objective was to develop the NC State Livestock Science Camp as a vehicle for student recruitment and diversification. Thirty youth 14–17 years old from a variety of backgrounds from across North Carolina attended the 5 day residential camp. The camp included hands-on lessons at each of 5 livestock educational units, laboratories on campus, and farm tours. Each session engaged the students in management tasks and discussed career options within that species or discipline. Following camp, participants were surveyed to assess their knowledge and interest change in camp topics. Across topics change was predominantly positive, 10–20%. Areas of greatest increase were: Experience with dairy cattle (22%), Knowledge of occupations in livestock production beyond veterinary medicine (16%), Experience with beef cattle (16%), and Understanding of animal quality assurance to promote safety and welfare for animals and consumers (14%). In addition, the NC State student counselors (n=11) rated the camp a 9 out of 10 for helping campers explore careers and hands-on experience in livestock production. Overall, a Livestock Science Camp program can be an effective way to increase youth knowledge and comfort in working with livestock species as well as their career interests in careers other than veterinary medicine. Key Words:}, number={suppl_3}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Pickworth, C}, year={2018}, month={Dec}, pages={497–498} }
 @article{ott_freeman_poore_pickworth_2018, title={27 Maternal Stress at Weaning Impacts Calf Growth.}, volume={96}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/sky027.028}, DOI={10.1093/jas/sky027.028}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Ott, G C and Freeman, S R and Poore, M H and Pickworth, C L}, year={2018}, month={Mar}, pages={14–15} }
 @article{poole_womble_pickworth_poole_2018, title={41 “Effect of Protein Supplementation on Immune Response of Weaned Steers Consuming Endophyte-Infected Tall Fescue Seed”.}, volume={96}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.1093/jas/sky027.041}, DOI={10.1093/jas/sky027.041}, abstractNote={Fescue toxicosis is a multifaceted disease that negatively impacts growth and performance. Cattle grazing endophyte-infected fescue have a depressed immune response to vaccinations. Therefore, the goal of this study was to evaluate the impact of protein supplementation on weaned calves’ physiological and immune responses while consuming an ergot alkaloid toxin (i.e. ergovaline) commonly produced by endophyte-infected tall fescue. Thirty-six naïve beef steers (196.1 ± 3.6 kg) were blocked by weight and randomly assigned to receive one of four treatments in a total mixed ration (TMR): endophyte-free seed (0 ppm ergovaline) and 18% protein supplementation (EF-18; n=9), endophyte-free seed and 14% supplementation (EF-14; n=9), endophyte-infected seed (500 ppm ergovaline) and 18% supplementation (EI-18; n=9), and endophyte-infected seed and 14% supplementation (EI-14; n=9). Diameter of caudal artery and vein were recorded weekly by ultrasound. On d14 of the feeding trial, iButton® temperature data loggers were inserted in the lateral neck region to hourly record the subcutaneous body temperature. On d28, steers were vaccinated against infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea (BVD) types 1 and 2 viruses. Steers received a booster two weeks later (d42). Blood samples were collected at d0, 42, and 56 to evaluate titers to IBR and BVDV1b. Data were analyzed using PROC MIXED of SAS with repeated measures. A treatment interaction was observed with EI-14 steers experiencing vasodilation of the caudal artery (27.4 mm2) in comparison to other steer groups (P<0.05; 26.8, 26.1, 25.8 ± 0.5 mm2 for EF-18, EF-14, and EI-18, respectively). A similar effect of greater caudal vein diameters was observed in EI-14 steers (35.0 mm2) when compared to other steer groups (P<0.05; 33.6, 32.8, 32.0 ± 0.6 mm2 for EF-18, EF-14, and EI-18, respectively). Subcutaneous body temperature was higher in EI-14 steers compared to EF-14 steers after the vaccination (P<0.05; 38.0 and 37.7 ± 0.1 °C, respectively) and booster (P<0.05; 37.9 and 37.6 ± 0.1 °C, respectively). A tendency was observed in the seroconversion of IBR and BVDV1b antibody titers with a greater seroconversion in EI-18 steers compared to EF-18 steers (P=0.09; 66.7 and 44.4 ± 9.2% for IBR and P=0.08, 66.7 and 48.2 ± 7.5% for BVDV1b, respectively), no differences were observed when compared to other steer groups. Overall, a unique response was observed in steers consuming ergovaline as a result of protein supplementation, with 14% protein effecting blood flow and 18% protein having a potential impact on the animal’s immune response.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Poole, R K and Womble, C M and Pickworth, C L and Poole, D H}, year={2018}, month={Mar}, pages={21–22} }
 @misc{pickworth_2018, title={Doe ewe have what they need to breed?}, author={Pickworth, C.L.}, year={2018} }
 @inproceedings{rosa_ott_pickworth_2018, title={The Impact of Weaning Stress on Beef Cattle Behavior}, author={Rosa, L. and Ott, G.C. and Pickworth, C.L.}, year={2018} }
 @book{pickworth_2017, title={ANS 102 Feeds and Nutrition}, author={Pickworth, C.L.}, year={2017} }
 @misc{pickworth_2017, title={Current Small Ruminant Research at NC State}, author={Pickworth, C.L.}, year={2017} }
 @misc{pickworth_2017, title={Do You Have What They Need?}, author={Pickworth, C.L.}, year={2017} }
 @inproceedings{roman_sheffield_pickworth_2017, title={Effects of Hay Restriction on Ewe Body Weight, Body Condition, and Conception Rates}, author={Roman, C. and Sheffield, J. and Pickworth, C.L.}, year={2017} }
 @inproceedings{pickworth_moore_2017, title={Experiential Learning in Animal Science}, author={Pickworth, C.L. and Moore, J.A.}, year={2017} }
 @inproceedings{womble_poole_pickworth_poole_2017, title={Impacts of Fescue Toxicosis and Protein Supplementation on Post-Vaccination Immune Responses of Beef Calves}, author={Womble, C. and Poole, R. and Pickworth, C. and Poole, D.}, year={2017} }
 @inproceedings{poole_pickworth_schaffer_2017, title={Promoting Student Learning via Automated Individualized Feedback}, author={Poole, D.H. and Pickworth, C.L. and Schaffer, H.E.}, year={2017} }
 @article{pickworth_bell_greene_whisnant_poole_2017, title={Site of PGF 2α injection does not alter effectiveness of the Select Synch + controlled internal drug release and timed artificial insemination protocol}, volume={87}, ISSN={0093-691X}, url={http://dx.doi.org/10.1016/j.theriogenology.2016.08.018}, DOI={10.1016/j.theriogenology.2016.08.018}, abstractNote={Beef Quality Assurance programs have contributed to significant improvements in the wholesomeness of beef available for consumption. Injection site blemishes in the round have declined since the promotion of administering intramuscular injections in the neck. Unfortunately, many producers continue to administer estrus synchronization (ES) drugs in the rump. The objective of this study was to compare the effectiveness of injection site of PGF2α, in ES protocols, on steroid hormone concentrations and pregnancy rates. A Select Synch + 7-day controlled internal drug release ES protocol was conducted with the site of PGF2α injection alternated between neck and rump in beef cattle (n = 312) at the Ohio State University Agricultural Technical Institute and North Carolina State University. Blood samples (n = 75) were collected at controlled internal drug release insertion and at the time of artificial insemination (AI) to determine if progesterone (P4) and estrogen (E2) concentrations varied due to PGF2α injection site. All cattle were confirmed pregnant by ultrasonography at approximately 30 and 90 days after insemination in North Carolina and approximately 70 days after insemination in Ohio. Data were analyzed as randomized complete block designs in PROC GLIMMIX with animal as the experimental unit. Differences were declared significant at P < 0.05. Site of PGF2α injection, in either the neck or rump, did not affect (P > 0.05) overall conception rates in response to AI (58.4% and 55.6%, respectively). Altering PGF2α injection site did not impact P4, E2 concentrations, or the P4:E2 ratio at AI (P > 0.05). However, cattle inseminated after displaying estrus had greater (P < 0.05) pregnancy rates than timed AI (67.8 vs. 47.5%, respectively). First service conception rates and pregnancy rates were consistent with previous reports. Overall, altering the location of the PGF2α injection during ES did not change circulating hormone concentrations at AI or pregnancy rates; therefore, cattle producers should follow Beef Quality Assurance guidelines when administering ES protocols.}, journal={Theriogenology}, publisher={Elsevier BV}, author={Pickworth, C.L. and Bell, L.M. and Greene, W. and Whisnant, C.S. and Poole, D.H.}, year={2017}, month={Jan}, pages={161–166} }
 @article{bostian_lyons_mackey_pickworth_poore_poole_2016, title={041 Chronic Exposure to Ergot Alkaloids Suppresses Growth Hormone in Beef Steers}, volume={95}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/ssasas2017.041}, DOI={10.2527/ssasas2017.041}, abstractNote={Tall fescue [Lolium arundinaceum (Schreb.) Darbysh] is the predominant grass that cattle graze throughout the southeastern United States. Due to its association with the fungus, Epichloë coenophiala, the grass becomes endophyte-infected and produces ergot alkaloids. Ergot alkaloid exposure causes a whole host of physiological problems in cattle including increased body temperature and heart rate, as well as decreased growth and blood flow to the extremities. Together, these symptoms are called fescue toxicosis and the exact pathway by which it occurs is not well understood. Crossbred Angus steers (n = 8) were placed in Calan gates and were randomly assigned to receive either endophyte-infected fescue seed (EI) or non-infected fescue seed (EF; control) for 60d. Weekly measurements and blood samples were taken to monitor the steer's physiological responses during exposure to ergot alkaloids. Data were analyzed using repeated measure in the MIXED procedure of SAS. Statistical significance was determined at P < 0.05 and a tendency at 0.05 < P < 0.10. Upon completion of the feeding period, animals were euthanized and tissue harvested to analyze impact on organ weight. Respiration rate, rectal temperature, surface temperature assessed by thermal camera, temperament, hair coat and shedding scores (1 to 5 scale) did not differ between treatment groups (P > 0.05). Systolic and diastolic blood pressure as well as caudal vein diameter were not different (P > 0.05). However, there was decreased heart rate (67.43 vs. 73.72 beats/min) and increased caudal artery diameter (35.58 vs. 34.38 mm2) in EI animals compared to EF (P < 0.05). Body weight and average daily gain (BW 425.8 vs 409.5 kg; ADG 0.99 vs 1.14 kg/d) tended to increase in the EF group compared to EI (P = 0.09). Body condition score tended to be greater in the EF group compared to EI (5.46 vs, 5.39; P = 0.07). Hematocrit was not different between treatment groups (P > 0.05). Heart, liver, spleen, kidney and pancreas weights did not differ between treatment groups (P > 0.05). Circulating luteinizing hormone (LH) concentrations were no different between treatment groups (P > 0.05) during chronic exposure to ergot alkaloids whereas, circulating growth hormone (GH) concentrations were reduced in the EI 1.3 ng/ml) group when compared to the EF controls (7.2 ng/ml; P < 0.05). Growth hormone could play an important role in the reduced weight gain that is seen in animals that are chronically exposed to ergot alkaloids. Determining exactly how ergot alkaloids are functioning along the hypothalamic-pituitary axis to alter GH production could help to further elucidate the mechanisms that leads to losses associated with fescue toxicosis.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Bostian, A. W. and Lyons, S. E. and Mackey, J. C. and Pickworth, C. L. and Poore, M. H. and Poole, D. H.}, year={2016}, month={Dec}, pages={20–20} }
 @article{freeman_pickworth poole_poore_alley_2016, title={085 Impact of Three Weaning Strategies on Calf Activity and Behavior at Weaning and Productivity after Weaning}, volume={95}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/ssasas2017.085}, DOI={10.2527/ssasas2017.085}, abstractNote={Weaning is a stressful time in a calf's life. Stress has been linked to reduced feed intake and diminished immune response predisposing calves to illness and poor gain. Applying anti-suckling nose flaps, to separate loss of milk from loss of contact with the dam, may reduce weaning stress. The goal of this study was to compare nose flaps (N) inserted 7 d before weaning, with abrupt weaning (A), and late weaning (L, 49 d later). Calves (n = 120, BW = 270 ± 18 kg) were blocked by hair coat quality (slick or normal at birth, as a part of a separate trial) and BW 28 d before traditional weaning and randomly assigned to treatment (10/treatment/year, 4 yr). Accelerometers were placed on 5 calves' necks/treatment/year to record relative activity 7 d prior to placement of nose flaps (A and N) or weaning (L). After collar placement, behavioral observations were made over 4 d per week for 1-h intervals beginning at 0730, 1130, and 1530h. At weaning, nose flaps were removed, A and N calves placed in a dry lot, dams of A and N relocated out of sight, and L calves with their dams relocated to a separate pasture for 49 d. Weaning age for A, N, and L was 249, 245, and 300 d ( ± 11), respectively. Data were analyzed with Proc Mixed of SAS. Accelerometer output showed similar activity patterns between treatments with a tendency for greater activity when calves were grazing in the absence of hay, than when hay was offered on pasture or during confinement (P = 0.07). Vocalizations were similar across treatments prior to weaning (2.6/steer/h; P > 0.26). Vocalizations were higher on d 1 and 2 after weaning for A (33 and 26/steer/h) and L (27 and 15/steer/h) steers as compared to N (6 and 3/steer/h, treatment P < 0.01), suggesting reduced stress. Vocalizations for A and L returned to preweaning levels by d 3 after weaning. Pacing comprised 19 and 20% of observations for A and L, respectively, during the same period and 14% for N (P < 0.01), also suggesting reduced stress. While N calves appeared less stressed at weaning, 42-d post-weaning ADG were greater for A and L (0.56 and 0.67 kg/d, respectively) than N (0.41 kg/d; P < 0.01). Of the calves that retained their flaps, 17 of 33 developed nasal ulcers from the flaps. While nose flap insertion reduced calf behavioral signs of stress, it also reduced post-weaning growth performance.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Freeman, S. R. and Pickworth Poole, C. L. and Poore, M. H. and Alley, M. L.}, year={2016}, month={Dec}, pages={42–42} }
 @article{price_pickworth_shaeffer_poore_2016, title={089 Effect of Concentration of Starch in Pasture-Finished Beef Cattle Supplementation on Growth, Carcass Traits, and Meat Quality}, volume={95}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/ssasas2017.089}, DOI={10.2527/ssasas2017.089}, abstractNote={The effect of starch supplementation on carcass characteristics in pasture-finished beef cattle is not known. An experiment was conducted to compare a fiber-based concentrate with a supplement containing starch from corn on performance and carcass characteristics. Angus and Angus × Simmental crossbred yearling cattle (heifers n = 6; steers n = 30) were separated into 4 groups balanced by weight and sex before each group was randomly assigned to 1 of 2 treatments. Treatment 1 (T1) received a concentrate pellet of 50% soybean hulls and 50% corn gluten feed while treatment 2 (T2) received a concentrate composed of 50% T1 pellets and 40.5% ground corn and 8.5% soybean meal. Supplements were isonitrogenous and fed at 1% of BW. Supplement offered was adjusted on BW every 28 d. Groups were randomly allotted to predominately fescue pastures and rotationally grazed for an average of 180 d. Cattle were slaughtered on 4 dates between October and November. The progressively heaviest 2 or 3 animals/group were selected for each slaughter date. An average of 1,886 kg/ha biomass with 14.7% CP and 66.7% TDN was available throughout the finishing period. Hot carcass weights were recorded at slaughter and back fat, marbling score, and ribeye area were obtained between the 12th and 13th rib after 11 d of dry aging. Two 2.5 cm thick strip steak at the 13th rib were collected from each carcass, vacuum sealed, and frozen at −16°C prior to slice shear force and subcutaneous fat color analyses. Data were analyzed using GLM procedures in SAS. Starting and final BW and ADG were not affected by treatment (318.0 and 318.5 kg, 493.3 and 494.9 kg, and 0.96 and 0.98 kg/d for T1 and T2, respectively; P > 0.10). Initial and change in BCS did not differ (5.47 and 5.52; 0.83 and 0.80 for T1 and T2, respectively; P > 0.10). Adding starch to concentrate supplement of pasture-finished cattle did not affect (P > 0.10) carcass characteristics. Overall, carcasses averaged 285 kg, were low choice, yield grade 2.5, and marbling score of 5.3. The L* and B* color spectrum of subcutaneous fat was similar between treatments (72.08 and 71.64, 16.14 and 14.56 for T1 and T2, respectively; P > 0.10), however, A* differed (1.01 and 2.64 between T1 and T2, respectively; P < 0.05). Starch supplementation did not alter meat tenderness (18.7 and 17.0 kg for T1 and T2, respectively; P > 0.10). Adding starch to a fiber-based concentrate may not impact growth, carcass characteristics, or meat quality of pasture-finished beef.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Price, C. T. and Pickworth, C. L. and Shaeffer, A. D. and Poore, M. H.}, year={2016}, month={Dec}, pages={44–44} }
 @article{pickworth_roper_garrison_2016, title={096 Limit Feeding Hay to Ewes}, volume={95}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/ssasas2017.096}, DOI={10.2527/ssasas2017.096}, abstractNote={Hay is often provided to ewes when pasture is limited in winter months. Hay resources can be a major component of feed costs and waste is often high. The objective of this study was to investigate the economic and production impacts of restricting ewe access to hay. Sixty-four ewes were blocked by breed, age, weight, and pregnancy status (open or early pregnancy) and then allotted to four groups. Groups were then randomly assigned to one of two treatments: continuous (CONT) or limited (LIMIT) access to round-bale grass hay for 56 d starting in early January. Each group of ewes was managed on a 0.7 ha dry-lot pasture with ad libitum access to water and mineral without any supplemental concentrate feed. The CONT maintained 24 h/d access to hay, while LIMIT were provided access to hay for 2 h/d starting at 0700 for the first 28 d (period 1) and then an additional 2 h/d at 1500 for the remaining 28 d (period 2). Ewe BW and BCS (adjusted 4 point scale) were recorded every 14 d. Weight of hay offered (8.8% CP, 45.4% ADF) and orts were recorded. Data were analyzed using PROC MIXED with repeated measures in SAS. During period 1, CONT had positive while LIMIT had negative ADG (0.16 ± 0.05 kg/d and −0.10 ± 0.05 kg/d, respectively; P < 0.0001) and BCS (0.23 ± 0.09 and −0.38 ± 0.09 scores, respectively; P < 0.0001). However in period 2, both treatments had negative ADG (−0.16 ± 0.04 and −0.15 ± 0.04 kg/d for CONT and LIMIT, respectively; P < 0.0001) and BCS (−0.27 ± 0.10 and −0.21 ± 0.09 scores for CONT and LIMIT, respectively; P < 0.0001). Throughout the study, BCS of open ewes was not affected by feeding treatment but pregnant CONT had greater BCS (P < 0.05) than LIMIT (3.62 ± 0.1 and 3.24 ± 0.1, respectively). Furthermore, there was a breed by treatment interaction (P < 0.05). Limiting ewe access to hay during a 56 d winter feeding period reduced total hay used per ewe (0.64 ± 0.02 and 1.14 ± 0.03 kg/d; P < 0.05) and cost of hay per ewe ($2.36 and $4.21; P < 0.05) when compared to continuous access to hay. While restricting ewe access to hay was economically viable for reducing the amount of hay used; the impact of BW and BCS loss during early gestation may limit this practice with low quality hay.}, number={suppl_1}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Pickworth, C. L. and Roper, B. L. and Garrison, G. B.}, year={2016}, month={Dec}, pages={48–48} }
 @inproceedings{pickworth_warner_2016, title={Cultivating advocacy skills and content knowledge: An evaluation of a course project}, author={Pickworth, C.L. and Warner, W.J.}, year={2016} }
 @misc{pickworth_2016, title={Current Small Ruminant Research at NC State}, author={Pickworth, C.L.}, year={2016} }
 @inproceedings{pickworth_warner_2016, title={Empowering students as industry ambassadors}, author={Pickworth, C.L. and Warner, W.J.}, year={2016} }
 @misc{pickworth_2016, title={Interpreting Forage Analysis Reports for Ruminants}, author={Pickworth, C.L.}, year={2016} }
 @inproceedings{kennedy_poore_goff_pickworth_2016, title={Is feeding seed to cattle through mineral supplements a viable alternative to frost-seeding red clover into endophyte-infected tall fescue pastures?}, booktitle={AFGC Proceedings}, author={Kennedy, P.M. and Poore, M.H. and Goff, B.M. and Pickworth, C.L.}, year={2016} }
 @article{kennedy_poore_goff_pickworth_unruh-snyder_2016, title={Pasture red clover establishment: broadcast versus fed}, journal={Hay & Forage Grower}, author={Kennedy, P.M. and Poore, M.H. and Goff, B. and Pickworth, C.L. and Unruh-Snyder, L.}, year={2016}, month={Mar}, pages={22} }
 @misc{pickworth_2016, title={Rumen Physiology and Its Impact on Nutrition}, author={Pickworth, C.L.}, year={2016} }
 @misc{pickworth_2016, title={Understanding and Interpreting Carcass Ultrasound Data}, author={Pickworth, C.L.}, year={2016} }
 @misc{pickworth_2016, title={Value of Facilities in Beef Management}, author={Pickworth, C.L.}, year={2016} }
 @inproceedings{pickworth_2015, title={Beef Cattle Carcass Quality}, author={Pickworth, C.L.}, year={2015} }
 @misc{pickworth_2015, title={Impact of Weaning Strategies on Meat Quality}, author={Pickworth, C.L.}, year={2015} }
 @misc{pickworth_2015, title={What Do All the Beef Labels Mean?}, author={Pickworth, C.L.}, year={2015} }
 @article{pickworth_fluharty_2014, title={Accurate data needed on carotenoid levels in feed}, journal={Feedstuffs}, author={Pickworth, C.L. and Fluharty, F.L.}, year={2014}, month={Sep} }
 @misc{pickworth_2014, title={Beef Management Impacts on Carcass Quality}, author={Pickworth, C.L.}, year={2014} }
 @inproceedings{mabry_greene_kniffen_pickworth_poole_2014, title={Site of prostaglandin injection does not alter effectiveness of estrous synchronization protocols}, author={Mabry, L.K. and Greene, W. and Kniffen, D.M. and Pickworth, C.L. and Poole, D.H.}, year={2014} }
 @inproceedings{pickworth_2013, title={Creating the University-High School Partnership}, author={Pickworth, C.L.}, year={2013} }
 @article{jee_hoet_azevedo_vlasova_loerch_pickworth_hanson_saif_2013, title={Effects of dietary vitamin A content on antibody responses of feedlot calves inoculated intramuscularly with an inactivated bovine coronavirus vaccine}, volume={74}, ISSN={0002-9645}, url={http://dx.doi.org/10.2460/ajvr.74.10.1353}, DOI={10.2460/ajvr.74.10.1353}, abstractNote={OBJECTIVE
To investigate effects of low dietary vitamin A content on antibody responses in feedlot calves inoculated with an inactivated bovine coronavirus (BCoV) vaccine.


ANIMALS
40 feedlot calves.


PROCEDURES
Calves were fed diets containing high (3,300 U/kg) or low (1,100 U/kg) amounts of vitamin A beginning on the day of arrival at a feedlot (day 0) and continuing daily until the end of the study (day 140). Serum retinol concentrations were evaluated in blood samples obtained throughout the study. Calves were inoculated IM with an inactivated BCoV vaccine on days 112 and 126. Blood samples obtained on days 112 and 140 were used for assessment of BCoV-specific serum IgG1, IgG2, IgM, and IgA titers via an ELISA.


RESULTS
The low vitamin A diet reduced serum retinol concentrations between days 112 and 140. After the BCoV inoculation and booster injections, predominantly serum IgG1 antibodies were induced in calves fed the high vitamin A diet; however, IgG1 titers were compromised at day 140 in calves fed the low vitamin A diet. Other isotype antibodies specific for BCoV were not affected by the low vitamin A diet.


CONCLUSIONS AND CLINICAL RELEVANCE
Dietary vitamin A restriction increases marbling in feedlot cattle; however, its effect on antibody responses to vaccines is unknown. A low vitamin A diet compromised the serum IgG1 responses against inactivated BCoV vaccine, which suggested suppressed T-helper 2-associated antibody (IgG1) responses. Thus, low vitamin A diets may compromise the effectiveness of viral vaccines and render calves more susceptible to infectious disease.}, number={10}, journal={American Journal of Veterinary Research}, publisher={American Veterinary Medical Association (AVMA)}, author={Jee, Junbae and Hoet, Armando E. and Azevedo, Marli P. and Vlasova, Anastasia N. and Loerch, Steve C. and Pickworth, Carrie L. and Hanson, Juliette and Saif, Linda J.}, year={2013}, month={Oct}, pages={1353–1362} }
 @misc{pickworth_2013, title={Impacts of Health from Conception to Slaughter on Meat Quality}, author={Pickworth, C.L.}, year={2013} }
 @article{pickworth_boyles_2012, title={Beef production student instructional video project}, volume={E90}, journal={Journal of Animal Science}, author={Pickworth, C.L. and Boyles, S.}, year={2012}, pages={497} }
 @inproceedings{pickworth_grimes_spears_2012, title={Chromium supplementation benefits for heat stressed broiler production}, author={Pickworth, C.L. and Grimes, J. and Spears, J.W.}, year={2012} }
 @article{pickworth_loerch_kopec_schwartz_fluharty_2012, title={Concentration of pro-vitamin A carotenoids in common beef cattle feedstuffs}, volume={90}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/jas.2011-4217}, DOI={10.2527/jas.2011-4217}, abstractNote={Quantification of the pro-vitamin A carotenoids in feedstuffs commonly fed to livestock has been ignored for many years. A greater dietary concentration of vitamin A has the potential to limit adipogenesis in cattle, thereby reducing carcass quality and value. A survey of 18 feedstuffs commonly fed to beef cattle was conducted for determination of vitamin A equivalents based on analysis of carotenoids. The pro-vitamin A carotenoids of interest were β-carotene, α-carotene, and β-cryptoxanthin. Collaborators in 5 states collected the feedstuffs and then shipped them to The Ohio State University for compilation and analysis. Carotenoids were extracted from the feedstuffs and then quantified using HPLC with photodiode array analysis. Fresh fescue pasture contained approximately 10 times more vitamin A equivalents than hay and 5 times more than corn silage (39,865, 2,750, and 6,900 IU of vitamin A/kg of DM for fresh pasture, hay, and corn silage, respectively). Beta-cryptoxanthin and α-carotene could not be detected in any forage samples. Hay and corn silage vitamin A equivalents decreased over extended periods of time from harvest to sample collection. Corn was the only feedstuff to have appreciable concentrations of all 3 pro-vitamin A carotenoids quantified. Corn processing had a minimal impact on the vitamin A equivalents. High-moisture corn contained 54% more vitamin A equivalents than whole shelled corn (378 and 174 IU of vitamin A/kg of DM, respectively). Pro-vitamin A carotenoids were more concentrated in corn coproducts than in whole shelled corn. The drying of distillers grains with solubles may significantly degrade β-carotene (800 and 480 IU/kg of DM for wet and dry distillers grains, respectively). Soybean-based feedstuffs contain a small concentration of pro-vitamin A carotenoids, at 55 and 45 IU of vitamin A/kg of DM for soybean meal and soybean hulls, respectively. Overall, there was considerable variation in the pro-vitamin A content of feedstuffs based on location and storage conditions. An extensive analysis of feedstuffs would need to be conducted for an accurate estimation of the vitamin A content of feedlot cattle diets.}, number={5}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Pickworth, C. L. and Loerch, S. C. and Kopec, R. E. and Schwartz, S. J. and Fluharty, F. L.}, year={2012}, month={May}, pages={1553–1561} }
 @article{pickworth_loerch_fluharty_2012, title={Effects of timing and duration of dietary vitamin A reduction on carcass quality of finishing beef cattle1}, volume={90}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/jas.2011-4756}, DOI={10.2527/jas.2011-4756}, abstractNote={Two feedlot studies were conducted to investigate the timing and duration of supplemental vitamin A withdrawal from feedlot cattle (Bos taurus) diets to reduce intramuscular adipose tissue vitamin A concentration and improve carcass quality. In Exp. 1, Angus crossbred steers (n = 84, BW = 211 ± 4 kg) were allotted to 4 treatments: no supplemental vitamin A for 227 d, no supplemental vitamin A for 112 d followed by 115 d of supplemental vitamin A, supplemental vitamin A for 112 d followed by no supplemental vitamin A for 115 d, or supplemental vitamin A for 227 d. In Exp. 2, Angus crossbred steers (n = 80, BW = 210 ± 5 kg) were allotted to 4 treatments: early weaning with or without supplemental vitamin A, and traditional weaning with or without supplemental vitamin A. In both experiments, serum vitamin A concentrations were greatest (P < 0.05) 56 d after cattle were weaned and placed in the feedlot, regardless of feedlot dietary vitamin A concentration. Hepatic vitamin A stores were dramatically decreased (P < 0.05) in the first 56 d and remained depressed as long as steers were not supplemented with vitamin A. At the end of the finishing period, vitamin A concentrations were less in intramuscular than subcutaneous adipose tissue. Growth was not affected by finishing cattle without supplemental dietary vitamin A (P > 0.10). Dietary vitamin A supplementation did not affect USDA yield grades. However, in Exp. 2, cattle without supplemental vitamin A had greater (P < 0.001) ether extractable lipid in the LM. Ether extractable lipid in the LM or marbling scores were enhanced when intramuscular adipose tissue vitamin A concentration was reduced in response to feeding diets without supplemental vitamin A.}, number={8}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Pickworth, C. L. and Loerch, S. C. and Fluharty, F. L.}, year={2012}, month={Aug}, pages={2677–2691} }
 @article{pickworth_poole_greene_2012, title={Injection site does not alter effectiveness of beef cattle synchronization}, volume={E90}, journal={Journal of Animal Science}, author={Pickworth, C.L. and Poole, D.H. and Greene, W.}, year={2012}, pages={325} }
 @article{pickworth_loerch_fluharty_2012, title={Restriction of vitamin A and D in beef cattle finishing diets on feedlot performance and adipose accretion}, volume={90}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/jas.2010-3590}, DOI={10.2527/jas.2010-3590}, abstractNote={Feedlot producers often exceed NRC recommendations for vitamin A and D supplementation; however, increased concentrations of these vitamins have been shown to limit adipocyte differentiation in vitro. A feedlot trial was conducted using 168 Angus crossbred steers (BW = 284 ± 0.4 kg) allotted to 24 pens. The experiment had a 2 × 2 factorial arrangement of treatments: no supplemental vitamin A or D (NAND), 3,750 IU vitamin A/kg dietary DM with no supplemental vitamin D (SAND), no supplemental vitamin A and 1,860 IU vitamin D/kg dietary DM (NASD), and 3,750 IU and 1,860 IU vitamin A and D/ kg dietary DM (SASD), respectively. Serum, liver, and intramuscular and subcutaneous adipose tissue retinol concentrations were decreased in (P < 0.001) in cattle fed the no supplemental vitamin A diets (NAND and NASD combined) compared with those consuming supplemental vitamin A (SAND and SASD combined) diets. In addition, intramuscular retinol concentration was 38% less than in the subcutaneous depot. Serum 25(OH)D(3) concentrations were reduced (P < 0.001) during the first 70 d when cattle were fed no supplemental vitamin D diets (NAND and SAND combined); however, liver 25(OH)D(3) concentrations remained unchanged (P > 0.10) through d 184. Serum and liver 25(OH)D(3) concentrations increased (P < 0.001) with vitamin D supplementation (NASD and SASD combined). The DMI, ADG, G:F, and morbidity were not affected (P > 0.10) by dietary concentration of vitamin A or D. There were vitamin A and D interactions (P < 0.03) for backfat thickness and USDA Yield grade. Cattle fed the NAND diet had greater (P < 0.03) Yield grades than other treatments because of greater (P < 0.005) 12th rib backfat thickness in NAND steers than the NASD and SAND steers. Vitamin D concentrations were attenuated and minimal carcass adiposity responses to vitamin D supplementation were observed. Feeding a diet without supplemental vitamin A increased (P < 0.05) Quality grades and marbling scores and tended (P = 0.06) to increase ether extractable lipid of the LM. As retinol and 25(OH)D(3) concentrations in feedlot cattle declined as a result of a lack of dietary supplementation, adipose accretion increased, resulting in elevated Quality and Yield grades. Withdrawal of supplemental vitamin A, D, or both from the finishing diet of feedlot beef cattle had minimal impact carcass composition.}, number={6}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Pickworth, C. L. and Loerch, S. C. and Fluharty, F. L.}, year={2012}, month={Jun}, pages={1866–1878} }
 @article{huang_lloyd_pickworth_spears_2012, title={Ruminal availability of iron in forages}, volume={E90}, journal={Journal of Animal Science}, author={Huang, Y.L. and Lloyd, K.E. and Pickworth, C.L. and Spears, J.W.}, year={2012}, pages={411} }
 @article{pickworth_loerch_velleman_pate_poole_fluharty_2011, title={Adipogenic differentiation state-specific gene expression as related to bovine carcass adiposity}, volume={89}, ISSN={0021-8812 1525-3163}, url={http://dx.doi.org/10.2527/jas.2010-3229}, DOI={10.2527/jas.2010-3229}, abstractNote={Genetic regulation of the site of fat deposition is not well defined. The objective of this study was to investigate adipogenic differentiation state-specific gene expression in feedlot cattle (>75% Angus; <25% Simmental parentage) of varying adipose accretion patterns. Four groups of 4 steers were selected via ultrasound for the following adipose tissue characteristics: low subcutaneous-low intramuscular (LSQ-LIM), low subcutaneous-high intramuscular (LSQ-HIM), high subcutaneous-low intramuscular (HSQ-LIM), and high subcutaneous-high intramuscular (HSQ-HIM). Adipose tissue from the subcutaneous (SQ) and intramuscular (IM) depots was collected at slaughter. The relative expression of adipogenic genes was evaluated using quantitative PCR. Data were analyzed using the mixed model of SAS, and gene expression data were analyzed using covariate analysis with ribosomal protein L19 as the covariate. No interactions (P > 0.10) were observed between IM and SQ adipose tissue depots for any of the variables measured. Therefore, only the main effects of high and low accretion within a depot and the effects of depot are reported. Steers with LIM had smaller mean diameter IM adipocytes (P < 0.001) than HIM steers. Steers with HSQ had larger mean diameter SQ adipocytes (P < 0.001) than LSQ. However, there were no differences (P > 0.10) in any of the genes measured due to high or low adipose accretion. Preadipogenic delta-like kinase1 mRNA was greater in the IM than the SQ adipose tissue; conversely, differentiating and adipogenic genes, lipoprotein lipase, PPARγ, fatty acid synthetase, and fatty acid binding protein 4 were greater (P < 0.001) in the SQ than the IM depot. Intramuscular adipocytes were smaller than SQ adipocytes and had greater expression of the preadipogenic gene, indicating that more hyperplasia was occurring. Meanwhile, SQ adipose tissue contained much larger (P < 0.001) adipocytes that had a greater expression (P < 0.001) of differentiating and adipogenic genes than did the IM adipose tissue, indicating more cells were undergoing differentiation and hypertrophy. Adipogenic differentiation state-specific gene expression was not different in cattle with various phenotypes, but adipogenesis in the SQ and IM adipose tissues seems to occur independently.}, number={2}, journal={Journal of Animal Science}, publisher={Oxford University Press (OUP)}, author={Pickworth, C. L. and Loerch, S. C. and Velleman, S. G. and Pate, J. L. and Poole, D. H. and Fluharty, F. L.}, year={2011}, month={Feb}, pages={355–366} }
 @article{pickworth_felix_susin_shoup_loerch_2011, title={Effects of supplemental dried distillers grains on performance and internal parasites of grazing lambs}, volume={E89}, journal={Journal of Animal Science}, author={Pickworth, C.L. and Felix, T.L. and Susin, I. and Shoup, L.M. and Loerch, S.C.}, year={2011}, pages={400} }
 @article{rodriguez-palacios_pickworth_loerch_lejeune_2011, title={Transient Fecal Shedding and Limited Animal-to-Animal Transmission of Clostridium difficile by Naturally Infected Finishing Feedlot Cattle}, volume={77}, ISSN={0099-2240 1098-5336}, url={http://dx.doi.org/10.1128/aem.02736-10}, DOI={10.1128/aem.02736-10}, abstractNote={ABSTRACT To longitudinally assess fecal shedding and animal-to-animal transmission of Clostridium difficile among finishing feedlot cattle as a risk for beef carcass contamination, we tested 186 ± 12 steers (mean ± standard deviation; 1,369 samples) in an experimental feedlot facility during the finishing period and at harvest. Clostridium difficile was isolated from 12.9% of steers on arrival (24/186; 0 to 33% among five suppliers). Shedding decreased to undetectable levels a week later (0%; P < 0.001), and remained low (<3.6%) until immediately prior to shipment for harvest (1.2%). Antimicrobial use did not increase fecal shedding, despite treatment of 53% of animals for signs of respiratory disease. Animals shedding C. difficile on arrival, however, had 4.6 times higher odds of receiving antimicrobials for respiratory signs than nonshedders (95% confidence interval for the odds ratio, 1.4 to 14.8; P = 0.01). Neither the toxin genes nor toxin A or B was detected in most (39/42) isolates based on two complementary multiplex PCRs and enzyme-linked immunosorbent assay testing, respectively. Two linezolid- and clindamycin-resistant PCR ribotype 078 (tcdA +/tcdB +/cdtB +/39-bp-type deletion in tcdC) isolates were identified from two steers (at arrival and week 20), but these ribotypes did not become endemic. The other toxigenic isolate (tcdA +/tcdB +/cdtB +/classic tcdC; PCR ribotype 078-like) was identified in the cecum of one steer at harvest. Spatio-temporal analysis indicated transient shedding with no evidence of animal-to-animal transmission. The association between C. difficile shedding upon arrival and the subsequent need for antimicrobials for respiratory disease might indicate common predisposing factors. The isolation of toxigenic C. difficile from bovine intestines at harvest highlights the potential for food contamination in meat processing plants.}, number={10}, journal={Applied and Environmental Microbiology}, publisher={American Society for Microbiology}, author={Rodriguez-Palacios, Alexander and Pickworth, Carrie and Loerch, Steve and LeJeune, Jeffrey T.}, year={2011}, month={May}, pages={3391–3397} }
 @article{pickworth_loerch_velleman_pate_poole_fluharty_2010, title={Adipocyte differentiation state specific gene expression as related to bovine carcass adiposity}, volume={E88}, journal={Journal of Animal Science}, author={Pickworth, C.L. and Loerch, S.C. and Velleman, S.G. and Pate, J.L. and Poole, D.H. and Fluharty, F.L.}, year={2010}, pages={822} }
 @inproceedings{pickworth_2010, title={Beef cattle finishing systems in the United States}, author={Pickworth, C.L.}, year={2010} }
 @article{greene_pickworth_2010, title={Effect of post-insemination GnRH on the pregnancy rate of beef cattle}, volume={E88}, journal={Journal of Animal Science}, author={Greene, W.A. and Pickworth, C.L.}, year={2010}, pages={266} }
 @article{pickworth_loerch_fluharty_2009, place={Montreal, Canada}, title={Effect of low vitamin A and D on beef cattle carcass quality}, volume={E87}, journal={Journal of Animal Science}, author={Pickworth, C.L. and Loerch, S.C. and Fluharty, F.L.}, year={2009}, pages={519} }
 @article{pickworth_loerch_fluharty_kopec_schwartz_2009, place={March}, title={Pro-vitamin A Carotenoids in Feedstuffs}, journal={American Society of Animal Science}, author={Pickworth, C.L. and Loerch, S.C. and Fluharty, F.L. and Kopec, R.E. and Schwartz, S.J.}, year={2009}, month={Mar}, pages={313} }
 @inproceedings{pickworth_loerch_fluharty_2008, title={Effect of dietary vitamin A on finishing beef cattle}, author={Pickworth, C.L. and Loerch, S.C. and Fluharty, F.L.}, year={2008} }
 @inproceedings{jee_azevedo_vlasova_hoet_loerch_pickworth_hanson_saif_2008, title={Effect of vitamin A on bovine coronovirus infection, vaccination and immunity in feedlot calves}, author={Jee, J. and Azevedo, M.P. and Vlasova, A. and Hoet, A. and Loerch, S.C. and Pickworth, C.L. and Hanson, J. and Saif, L.J.}, year={2008} }
 @inproceedings{pickworth_loerch_fluharty_2008, title={Effect of vitamin A on finishing beef cattle}, author={Pickworth, C.L. and Loerch, S.C. and Fluharty, F.L.}, year={2008} }
 @inproceedings{pickworth_loerch_fluharty_2008, title={Limit-feeding can improve feed efficiency of beef cattle}, author={Pickworth, C.L. and Loerch, S.C. and Fluharty, F.L.}, year={2008} }
 @misc{pickworth_2007, title={Beef Feedlot Management School}, author={Pickworth, C.L.}, year={2007} }
 @inproceedings{scaglia_swecker_pickworth_shanklin_2006, title={Forage based backgrounding systems for beef cattle}, author={Scaglia, G. and Swecker, W.S. and Pickworth, C.L. and Shanklin, R.K.}, year={2006} }
 @inproceedings{pickworth_scaglia_swecker_fontentot_wahlberg_abaye_2006, title={Tall fescue type effects of backgrounded calf health and performance}, author={Pickworth, C.L. and Scaglia, G. and Swecker, W.W., Jr. and Fontentot, J.P. and Wahlberg, M.L. and Abaye, O.}, year={2006} }
 @inproceedings{pickworth_scaglia_swecker_fotentot_wahlberg_2006, title={The effects of supplementation frequency and transportation stress on the performance and health of newly weaned calves}, author={Pickworth, C.L. and Scaglia, G. and Swecker, W.W., Jr. and Fotentot, J.P. and Wahlberg, M.L.}, year={2006} }
 @book{pickworth_morishita_2003, title={Common External Parasites in Poultry: Lice and Mites}, number={VME-18–03}, author={Pickworth, C.L. and Morishita, T.Y.}, year={2003} }
 @book{pickworth_morishita_2003, title={Less Common External Parasites in Poultry}, number={VME-19-03}, author={Pickworth, C.L. and Morishita, T.Y.}, year={2003} }