@article{poole_devine_mayberry_eisemann_poore_long_poole_2019, title={Impact of slick hair trait on physiological and reproductive performance in beef heifers consuming ergot alkaloids from endophyte-infected tall fescue}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz024}, abstractNote={Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue. The objective of this study was to evaluate the impact of the slick hair trait on physiological and reproductive parameters in heifers experiencing fescue toxicosis. Angus × Senepol heifers (n = 31) were blocked by weight (393.5 ± 17.3 kg) and phenotype relative to hair coat at birth, and randomly fed novel endophyte fescue (EN) or endophyte-infected fescue (EI) haylage in a total mixed ration for 91 d. Weekly measurements were collected to monitor heifer growth and response during ergot alkaloids exposure. Following 28 d of treatment, estrus was synchronized and heifers were inseminated. Ovary mapping and AI pregnancy rate were examined via transrectal ultrasonography. Blood samples were taken for genotyping: slick (S) or wildtype (W). Data were analyzed using repeated measures in PROC MIXED of SAS including fescue treatment (EN vs. EI), genotype (S vs. W), and sample collection time as main effects. Body condition scores were decreased for W heifers compared with S heifers (5.48 vs. 5.66, respectively; P < 0.0001). Surface temperature was greater for EI-W heifers (37.2 °C) compared with other groups (36.4, 36.6, 36.7 °C for EN-S, EN-W, EI-S, respectively; P < 0.05). Serum PRL concentrations were reduced for EI heifers compared with EN heifers (133.5 vs. 163.1 ng/mL, respectively; P < 0.05). The average number of 2 to 4 mm follicles were greater in EI-W heifers (13.8 follicles) compared with other groups (12.2, 10.6, and 11.1 for EN-S, EN-W, and EI-S, respectively; P < 0.0001). However, the average number of preovulatory follicles (≥9 mm) were reduced in EI-W heifers (0.52 follicles) compared with other heifer groups (0.94, 0.88, and 0.85 ± 0.04 for EN-S, EN-W, and EI-S, respectively; P < 0.05). Ovulatory follicle size was smaller in EI-W heifers compared with EN-W heifers (9.14 vs. 11.57 mm, respectively; P = 0.05). Corpus luteum area was reduced in EI-W heifers (235.1 mm2) compared with other heifer groups (297.2, 272.7, and 276.8 mm2 for EN-S, EN-W, and EI-S, respectively; P < 0.05). Concentrations of P4 were greater for EN heifers compared with EI heifers (2.7 vs. 1.8 ng/mL, respectively; P < 0.05). Pregnancy was not established in EI-W heifers (0%) compared with other heifer groups (37.5%, 57.1%, and 62.5% for EN-S, EN-W, and EI-S, respectively; P < 0.05). Overall, the slick hair mutation appears to aid in offsetting the physiological symptoms associated with fescue toxicosis and helps to improve reproductive performance.}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Poole, Rebecca K. and Devine, Thomas L. and Mayberry, Kyle J. and Eisemann, Joan H. and Poore, Matt H. and Long, Nathan M. and Poole, Daniel H.}, year={2019}, month={Apr}, pages={1456–1467} }
 @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{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} }
 @article{poole_lyons_poole_poore_2018, title={Ergot alkaloids induce vasoconstriction of bovine uterine and ovarian blood vessels}, volume={96}, ISSN={["1525-3163"]}, DOI={10.1093/jas/sky328}, abstractNote={Fescue toxicosis is a syndrome that impairs growth and reproduction in cattle grazing endophyte-infected tall fescue [Lolium arundinaceum [(Schreb.].) Darbysh)] in the United States, resulting in approximately $1 billion in annual economic loss in species that utilize this forage resource. Approximately 90% of tall fescue contains an endophytic fungus (Epichloë coenophiala) that produces ergot alkaloids. Ergot alkaloids cause vasoconstriction and reduced blood flow to the extremities; however, it remains unknown how blood flow to the reproductive organs is affected in cattle. Therefore, the objective of this study was to determine if ergot alkaloids from endophyte-infected tall fescue reduce blood flow to the reproductive organs, thus hindering reproductive function. Angus heifers (n = 36) naïve to ergot alkaloids were placed in Calan gates and randomly assigned to receive either endophyte-infected fescue seed (E+) or noninfected fescue seed (E-; control) in a total mixed ration for 63 d. Weekly measurements were taken to monitor heifer growth and response to ergot alkaloid exposure. Reproductive measurements, including ovarian structures, uterine and ovarian vessel diameter, and hormone concentrations were determined after heifers were synchronized using the standard CO-Synch + 7 d CIDR protocol to ensure all measurements were collected at the same stages of the estrous cycle (0, 4, 10, and 17 d). Data were analyzed using repeated measures in PROC MIXED of SAS. Average daily gain was decreased for the E+ group (0.8 kg/d) compared to control heifers (1.0 kg/d). Body condition scores tended to be greater in control heifers compared to the E+ group (P = 0.053). Additionally, hair coat and hair shedding scores were greater in E+ heifers compared to controls (P < 0.05). Heart rate, rectal temperature, respiration rate, and blood pressure did not differ between treatments (P > 0.05). Vasoconstriction was observed in the caudal artery, but not the caudal vein, in heifers consuming the E+ fescue seed (P < 0.05). No differences were observed in antral follicle counts, corpus luteum area or circulating progesterone concentrations in E+ heifers compared to controls (P > 0.05). There was a significant decrease in the diameter of arteries and veins servicing the ovary and uterus on day 10 and 17 of the estrous cycle. Reduction in blood flow to the reproductive organs during critical times in the estrous cycle may contribute to the reduced ovarian function and pregnancy rates associated with fescue toxicosis.}, number={11}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Poole, Daniel H. and Lyons, Sarah E. and Poole, Rebecca K. and Poore, Matt H.}, year={2018}, month={Nov}, pages={4812–4822} }
 @article{newsome_monn_mayberry_poole_young_poore_poole_2018, title={Grazing Novel or Endophyte-Infected Tall Fescue during Mid-Gestation Impacts Cow Performance.}, volume={96}, ISSN={["1525-3163"]}, DOI={10.1093/jas/sky027.025}, abstractNote={Consumption of endophyte-infected tall fescue results in poor reproductive performance. The objective of this study was to examine physiological changes in pregnant cows grazing tall fescue to develop a better understanding of the factors that contribute to the poor reproductive performance attributed to fescue toxicosis. Pregnant Angus and Simmental-Angus cows were blocked by age (2–3, 4–7, and >7 y), BW, and breed; and then randomly assigned to graze either novel (E-; <5% infection rate; n=27) or endophyte-infected tall fescue (E+; 79.5% infection rate; n=27). Weekly BW, BCS, hair coat scores (HCS), and hair shedding scores (HSS) were collected from mid-April through July when ergot alkaloid concentrations are greatest in the forage. Blood samples were collected to measure progesterone concentrations. Forage samples were taken every 2 wks to determine forage quality and composition. Data were analyzed using the MIXED procedure of SAS with repeated measures examined for effects of age, treatment (E- or E+) and time. Statistical significance was determined at P<0.05 and a tendency at 0.05<P<0.10. Pastures consisted of 69% and 67.5% available fescue for the novel and endophyte infected pastures, respectively. Average daily gain tended to be higher in E- cows than E+ (0.16, 0.01 kg/d, respectively; P=0.09). Cows on E- pastures had greater BCS compared to cows on E+ pastures (6.09, 5.77, respectively; P<0.05). Similarly, an age effect was observed with mature (4–7 and >7 y) cows having higher scores when compared to younger cows (6.0, 6.1, and 5.7, respectively; P<0.05). The HCS and HSS were greater in cows on E+ pastures compared to cows on E- pastures (P<0.05). The HSS were greater in the >7 y cows (2.69) compared to other age groups (2.40, 2.51, for 2–3 and 4–7 y, respectively, P<0.05) on E+ pastures, whereas no age differences in HCS were observed in cows on E- pastures. By d21 of the grazing period, cows on E- pastures displayed a greater ability to shed hair compared to cattle on E+ pastures (P<0.0001), which continued throughout the remainder of the grazing period. Progesterone concentrations in E+ cows (3.75 ng/ml) were decreased throughout the grazing period compared to E- cows (6.53 ng/mL, P<0.05). The impact of reduced progesterone concentrations, greater HCS and HSS and tendency for decreased ADG in cows grazing E+ during mid-gestation, compared to cows grazing E-, on calf development remains unknown.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Newsome, M. A. and Monn, R. E. and Mayberry, K. and Poole, R. K. and Young, Z. and Poore, M. H. and Poole, D. H.}, year={2018}, month={Mar}, pages={13–13} }