@article{haimon_poole_newsome_brown_dudley_poole_2024, title={Examining the long-term impacts of ergot alkaloids on fetal heifer development and subsequent growth and reproductive performance}, volume={102}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skae210}, abstractNote={Consumption of toxic endophyte-infected tall fescue (EI) results in poor reproductive performance in domestic livestock. In this study, the objective was to evaluate the effects of ergovaline exposure during mid-gestation (days 93 through 188 of gestation) on dam performance, the growing female fetus, and the subsequent growth and reproductive performance of the gestationally exposed heifer calves. Pregnant Angus and Simmental-Angus cows were blocked by age (2 to 3, to 7, and >7 y), body weight (BW), and breed; and then randomly assigned to graze either novel endophyte-infected tall fescue (EN; <5% infection rate; n = 27 year 1, n = 16 year 2) or toxic EI (99% infection rate; n = 27 year 1, n = 17 year 2). Weekly BW, body condition scores (BCS), hair coat scores, hair shedding scores (HSS), and blood samples for progesterone (P4) analysis were collected from mid-April through July of 2017 (year 1) and 2018 (year 2). Gestation length, birth weight, placental characteristics, heifer calf growth, onset of puberty, ovarian characteristics, and artificial insemination pregnancy rates were measured. Data were analyzed using the MIXED procedure of SAS. Cows grazing EI pastures had reduced average daily gain, reduced BCS, greater HSS, and decreased P4 concentrations compared to cows on EN pasture (P < 0.01). Birth weights were decreased for heifers whose dams were exposed to EI pastures during their second trimester (P < 0.01). Heifer pregnancy rates were not impacted by EI pasture exposure during gestation for either year of the study. However, a treatment-by-year effect was seen for the pregnancy rate for EI-exposed heifers in year 2; EI-exposed heifers in year 2 had increased pregnancy rates at two of the inseminations. Combined, these data reinforce that consumption of toxic EI during gestation can negatively impact both dam and offspring performance. More studies are needed to evaluate more parameters in an effort to elucidate the possible life-long impacts of ergovaline exposure during gestation.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Haimon, McKenzie L. J. and Poole, Rebecca K. and Newsome, McKayla A. and Brown, Alecia R. and Dudley, Harrison and Poole, Daniel H.}, year={2024}, month={Aug} }
 @article{poole_mayberry_newsome_poole_galliou_khanal_poore_serao_2020, title={Evaluation of Resistance to Fescue Toxicosis in Purebred Angus Cattle Utilizing Animal Performance and Cytokine Response}, volume={12}, ISSN={["2072-6651"]}, DOI={10.3390/toxins12120796}, abstractNote={Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue; however, varying symptomatic responses potentially imply genetic tolerance to the syndrome. It was hypothesized that a subpopulation of animals within a herd would develop tolerance to ergot alkaloid toxicity. Therefore, the goals of this study were to develop selection criteria to identify tolerant and susceptible animals within a herd based on animal performance, and then examine responsive phenotypic and cytokine profiles to fescue toxicosis. Angus cows grazed endophyte-infected tall fescue at two locations for 13 weeks starting in mid-April 2016. Forage measurements were collected to evaluate ergot alkaloid exposure during the study. A post hoc analysis of animal performance was utilized to designate cattle into either tolerant or susceptible groups, and weekly physiological measurements and blood samples were collected to evaluate responses to chronic exposure to endophyte-infected tall fescue. Findings from this study support the proposed fescue toxicosis selection method formulated herein, could accurately distinguish between tolerant and susceptible animals based on the performance parameters in cattle chronically exposed to ergot alkaloids, and provides evidence to warrant additional analysis to examine the impact of ergot alkaloids on immune responsiveness in cattle experiencing fescue toxicosis.}, number={12}, journal={TOXINS}, author={Poole, Daniel H. and Mayberry, Kyle J. and Newsome, McKayla and Poole, Rebecca K. and Galliou, Justine M. and Khanal, Piush and Poore, Matthew H. and Serao, Nick V. L.}, year={2020}, month={Dec} }
 @article{mayberry_poole_newsome_khanal_poore_serao_poole_2019, title={Evaluation of cytokine response as an indicator of genetic resistance to fescue toxicosis in purebred Angus cattle.}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz053.102}, abstractNote={Abstract
               Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue. However, varying responses among cattle potentially implies genetic tolerance to the syndrome. Therefore, the objective was to evaluate the cytokine response of cows deemed either tolerant or susceptible to endophyte-infected fescue. Angus cows, 2–4 yrs old, grazed endophyte-infected tall fescue at two locations for 13 weeks starting mid-April 2016. A post-hoc analysis of animal performance was utilized to designate cattle into either tolerant (n = 20) or susceptible (n = 20) groups, based on physiological responses (changes in ADG) to chronic exposure to endophyte-infected fescue. Blood samples collected on weeks 1, 7, and 13 were used to evaluate serum prolactin (PRL) concentration. Cytokine concentrations were evaluated via Quantibody Bovine Cytokine Arrays. Data were analyzed using PROC MIXED of SAS with repeated measures. There were no differences by location or week. Tolerant cows tended to have decreased overall PRL concentrations compared to susceptible cows (98.3 and 138.4 ng/mL, respectively; P = 0.08). G protein-coupled receptor associated sorting protein (GASP)-1, a down-regulator of G protein-coupled receptors including D2-dopamine receptor a regulator of PRL secretion, was greater in tolerant cows when compared to susceptible cows (4.7 and 4.2 ng/mL; P = 0.03). Vascular endothelial growth factor (VEGF)-A was greater in tolerant cows when compared to susceptible cows (0.5 and 0.2 ng/mL; P = 0.02). Finally, interleukin (IL)-4, an anti-inflammatory cytokine, tended to be greater in tolerant cows when compared to susceptible cows (2.2 and 0.8 ng/mL, respectively; P = 0.07). Based on these data, greater concentrations of GASP-1, VEGF-A, and IL-4 in tolerant compared to susceptible cattle may mitigate the detrimental effects of fescue toxicosis, including suppressed PRL and vasoconstriction, leading to improved animal performance in a fescue environment. Additionally, these cytokines may serve as potential biomarkers for determining an animal’s tolerance or susceptibility to negative effects associated with endophyte-infected tall fescue}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Mayberry, Kyle and Poole, Rebecca K. and Newsome, McKayla A. and Khanal, Piush and Poore, Matthew H. and Serao, Nick V. L. and Poole, Daniel H.}, year={2019}, month={Jul}, pages={45–46} }
 @article{jackson_newsome_brown_poole_dudley_poore_poole_2019, title={Long term impact of ergot alkaloids on fetal heifer development and subsequent growth and reproductive performance.}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz053.103}, abstractNote={Abstract
               Previous studies from our laboratory have demonstrated physiological differences in mid-gestation cows grazing either endophyte-infected (EI) or endophyte-free (EF) tall fescue. The objective of this study was to investigate the effects of in utero exposure (TRT) of either EI or EF on heifer growth, reproductive tract development and onset of puberty. Pregnant Angus and SimAngus cows were blocked by age, BW, and breed; and then randomly assigned to graze either EF (n = 27) or EI (n = 27) pastures. At parturition, heifer birthweight was recorded and placental tissues were collected to assess placental characteristics. Heifer BW, height, frame score were recorded at weaning. Assessment of puberty via measurement of BW, BCS, reproductive tract scores (RTS) and pelvic area (PA) started at 10 mo of age. Data were analyzed using a MIXED procedure of SAS and examined for effects of TRT, sire, and age. Statistical significance was determined at P < 0.05 and a tendency at 0.05); however, there was a sire by treatment interaction for ADG during onset of puberty (P < 0.05). While TRT did not affect PA or RTS (P > 0.05) at 10 mo of age, sire significantly influenced RTS (P < 0.05) thus impacting of onset of puberty. While consumption of EI fescue impacts cow performance, calf birthweight, and ratio of cotyledon to placenta weight, it has minimal effect on postnatal growth and development through 10 mo of age. Further studies are needed to determine the impact on heifer reproductive performance.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Jackson, McKenzie Lane and Newsome, McKayla A. and Brown, Alecia R. and Poole, Rebecca K. and Dudley, Harrison B. and Poore, Matthew H. and Poole, Daniel H.}, year={2019}, month={Jul}, pages={46–46} }
 @article{smith_poole_mayberry_newsome_dudley_poole_2019, title={Timing of progesterone exposure effects pregnancy rates following fixed time artificial insemination in postpartum beef cows.}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz053.098}, abstractNote={Abstract
               Advancements in reproductive technologies have improved pregnancy rates in postpartum cows; however, undesirable consequences leading to reduced fertility still occur. Thus, the objectives were to determine if presence of a corpus luteum (CL) at the start of estrous synchronization (AIM1) or if the length of proestrus (interval from progesterone removal to a GnRH-induced LH surge; AIM2) alters fixed timed artificial insemination (FTAI) pregnancy rates. Cycling postpartum cows (n = 285) at two locations were synchronized using the CO-Synch+CIDR® FTAI protocol. Ultrasonographic measurements of luteal area were recorded at CIDR insertion. To determine the impact of proestrus length, cows were randomly assigned to either undergo CIDR removal at the time of PGF2a injection (long proestrus, n = 145), or CIDR removal 24 hours post PGF2a injection (short proestrus, n = 140). Blood samples were collected at CIDR insertion and at insemination for progesterone (P4) analysis. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of length of proestrus, P4 concentration, luteal area, sire, location, and age. Statistical significance was determined at P0.05) pregnancy rates. Pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with 0.05). Cows > 4 y old had higher AI pregnancy rates compared to 2–3 y cows (70.2±7.4 vs. 51±5.8%, respectively; P > 0.05). Based on these data, incorporating a presynchronization program to ensure the presence of a functional CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Smith, Anna L. and Poole, Rebecca K. and Mayberry, Kyle and Newsome, McKayla A. and Dudley, Harrison B. and Poole, Daniel H.}, year={2019}, month={Jul}, pages={43–44} }
 @article{smith_poole_mayberry_newsome_dudley_poole_2019, title={Timing of progesterone exposure effects pregnancy rates following fixed timed artificial insemination in postpartum beef cows.}, volume={97}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skz053.195}, abstractNote={Abstract
               Advancements in reproductive technologies have improved pregnancy rates in postpartum cows; however, undesirable consequences leading to reduced fertility still occur. Thus, the objectives were to determine if presence of a corpus luteum (CL) at the start of estrous synchronization (AIM1) or if the length of proestrus (interval from progesterone removal to a GnRH-induced LH surge; AIM2) alters fixed timed artificial insemination (FTAI) pregnancy rates. Cycling postpartum cows (n = 285) at two locations were synchronized using the CO-Synch+CIDR® FTAI protocol. Ultrasonographic measurements of luteal area were recorded at CIDR insertion. To determine the impact of proestrus length, cows were randomly assigned to either undergo CIDR removal at the time of PGF2a injection (long proestrus, n = 145), or CIDR removal 24 hours post PGF2a injection (short proestrus, n = 140). Blood samples were collected at CIDR insertion and at insemination for progesterone (P4) analysis. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of length of proestrus, P4 concentration, luteal area, sire, location, and age. Statistical significance was determined at P 0.05) pregnancy rates. Pregnancy rates were greater in cows with >1 ng/mL P4 compared to cows with 0.05). Cows > 4 y old had higher AI pregnancy rates compared to 2–3 y cows (70.2±7.4 vs. 51±5.8%, respectively; P > 0.05). Based on these data, incorporating a presynchronization program to ensure the presence of a functional CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Smith, Anna L. and Poole, Rebecca K. and Mayberry, Kyle and Newsome, McKayla A. and Dudley, Harrison B. and Poole, Daniel H.}, year={2019}, month={Jul}, pages={85–85} }
 @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} }