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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.
Daniel H. Poole; Kyle J. Mayberry; McKayla Newsome; Rebecca K. Poole; Justine M Galliou; Piush Khanal; Matthew H. Poore; Nick V. L. Serão. Evaluation of Resistance to Fescue Toxicosis in Purebred Angus Cattle Utilizing Animal Performance and Cytokine Response. Toxins 2020, 12, 796 .
AMA StyleDaniel H. Poole, Kyle J. Mayberry, McKayla Newsome, Rebecca K. Poole, Justine M Galliou, Piush Khanal, Matthew H. Poore, Nick V. L. Serão. Evaluation of Resistance to Fescue Toxicosis in Purebred Angus Cattle Utilizing Animal Performance and Cytokine Response. Toxins. 2020; 12 (12):796.
Chicago/Turabian StyleDaniel H. Poole; Kyle J. Mayberry; McKayla Newsome; Rebecca K. Poole; Justine M Galliou; Piush Khanal; Matthew H. Poore; Nick V. L. Serão. 2020. "Evaluation of Resistance to Fescue Toxicosis in Purebred Angus Cattle Utilizing Animal Performance and Cytokine Response." Toxins 12, no. 12: 796.
Tall fescue (Lolium arundinaceum) is a widely used forage grass which shares a symbiosis with the endophytic fungus Epichloë coenophiala. The endophyte produces an alkaloid toxin that provides herbivory, heat and drought resistance to the grass, but can cause fescue toxicosis in grazing livestock. Fescue toxicosis can lead to reduced weight gain and milk yields resulting in significant losses to the livestock industry. In this trial, 149 Angus cows across two farms were continuously exposed to toxic, endophyte-infected, fescue for a total of 13 weeks. Of those 149 cows, 40 were classified into either high (HT) or low (LT) tolerance groups according to their growth performance (weight gain). 20 HT and 20 LT cattle balanced by farm were selected for 16S rRNA gene and ITS1 region Illumina MiSeq amplicon sequencing to compare the fecal microbiota of the two tolerance groups. This study reveals significantly (P) different bacterial and fungal microbiota between HT and LT cattle, and indicates that fungal phylotypes may be important for an animal’s response to fescue toxicosis: We found that fungal phylotypes affiliating to the Neocallimastigaceae, which are known to be important fiber-degrading fungi, were consistently more abundant in the HT cattle. Whereas fungal phylotypes related to the genus Thelebolus were more abundant in the LT cattle. This study also found more pronounced shifts in the microbiota in animals receiving higher amounts of the toxin. We identified fungal phylotypes which were consistently more abundant either in HT or LT cattle and may thus be associated with the respective animal’s response to fescue toxicosis. Our results thus suggest that some fungal phylotypes might be involved in mitigating fescue toxicosis. The results of our study provide a basis for investigating the functional role of the gastrointestinal microbiota in fescue toxicosis in more detail in the future.
Lucas R Koester; Daniel H Poole; Nick Vl Serão; Stephan Schmitz-Esser. Beef cattle that respond differently to fescue toxicosis have distinct gastrointestinal tract microbiota. 2020, 1 .
AMA StyleLucas R Koester, Daniel H Poole, Nick Vl Serão, Stephan Schmitz-Esser. Beef cattle that respond differently to fescue toxicosis have distinct gastrointestinal tract microbiota. . 2020; ():1.
Chicago/Turabian StyleLucas R Koester; Daniel H Poole; Nick Vl Serão; Stephan Schmitz-Esser. 2020. "Beef cattle that respond differently to fescue toxicosis have distinct gastrointestinal tract microbiota." , no. : 1.
Fescue toxicosis is a multifaceted syndrome that elicits many negative effects on livestock consuming ergot alkaloids produced by endophyte-infected tall fescue. The economic losses associated with fescue toxicosis are primarily due to reproductive failure including altered cyclicity, suppressed hormone secretion, reduced pregnancy rates, agalactia, and reduced offspring birth weights. For decades, a multitude of research has investigated the physiological and cellular mechanisms of these reproductive failures associated with fescue toxicosis. This review will summarize the various effects of ergot alkaloids on female reproduction in grazing livestock species.
Rebecca Poole; Daniel H. Poole. Impact of Ergot Alkaloids on Female Reproduction in Domestic Livestock Species. Toxins 2019, 11, 364 .
AMA StyleRebecca Poole, Daniel H. Poole. Impact of Ergot Alkaloids on Female Reproduction in Domestic Livestock Species. Toxins. 2019; 11 (6):364.
Chicago/Turabian StyleRebecca Poole; Daniel H. Poole. 2019. "Impact of Ergot Alkaloids on Female Reproduction in Domestic Livestock Species." Toxins 11, no. 6: 364.
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.
C.L. Pickworth; L.M. Bell; W. Greene; C.S. Whisnant; D.H. Poole. Site of PGF 2α injection does not alter effectiveness of the Select Synch + controlled internal drug release and timed artificial insemination protocol. Theriogenology 2017, 87, 161 -166.
AMA StyleC.L. Pickworth, L.M. Bell, W. Greene, C.S. Whisnant, D.H. Poole. Site of PGF 2α injection does not alter effectiveness of the Select Synch + controlled internal drug release and timed artificial insemination protocol. Theriogenology. 2017; 87 ():161-166.
Chicago/Turabian StyleC.L. Pickworth; L.M. Bell; W. Greene; C.S. Whisnant; D.H. Poole. 2017. "Site of PGF 2α injection does not alter effectiveness of the Select Synch + controlled internal drug release and timed artificial insemination protocol." Theriogenology 87, no. : 161-166.
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.
A. W. Bostian; S. E. Lyons; J. C. Mackey; C. L. Pickworth; M. H. Poore; D. H. Poole. 041 Chronic Exposure to Ergot Alkaloids Suppresses Growth Hormone in Beef Steers. Journal of Animal Science 2016, 95, 20 -20.
AMA StyleA. W. Bostian, S. E. Lyons, J. C. Mackey, C. L. Pickworth, M. H. Poore, D. H. Poole. 041 Chronic Exposure to Ergot Alkaloids Suppresses Growth Hormone in Beef Steers. Journal of Animal Science. 2016; 95 (suppl_1):20-20.
Chicago/Turabian StyleA. W. Bostian; S. E. Lyons; J. C. Mackey; C. L. Pickworth; M. H. Poore; D. H. Poole. 2016. "041 Chronic Exposure to Ergot Alkaloids Suppresses Growth Hormone in Beef Steers." Journal of Animal Science 95, no. suppl_1: 20-20.
Research on host genetic response to fescue toxicosis (FT), a major disease in cattle, is scarce in the literature. The objective of this study was to evaluate the effect of genetic response to FT on body weight (BW), body temperature (BT), and hair coat (HCS), hair shedding (HSS) and body condition (BCS) scores. Weekly data on 149 multiparous purebred pregnant Angus cows were collected for 13 weeks (April to July) at two locations in NC (Butner and Reidsville). Forty cows with contrasting performance were classified as either high tolerant (HT) or low tolerant (LT) to FT. Animals were selected based on their average weekly gain (regression of BW on weeks) after adjustment for fixed-effects of parity, location, and initial body weight, with 20 cows in each group balanced by location. Data on selected animals was analyzed as repeated measures over time including the fixed-effects of tolerance to FT (genotype), location, weeks, all interactions between these effects, parity, and initial measurement of the trait analyzed as covariate, and the random effect of animals in first order autoregressive co-variance structure in SAS. Genotype*Location was significant (P < 0.05) for HCS and HSS, where LT-Reidsville cows had greater HCS (2.72 ± 0.14) and HSS (3.00 ± 0.15) than HT-Reidsville, LT-Butner and HT-Butner cows, with 1.91 ± 0.13 and 2.18 ± 0.15, 2.10 ± 0.14 and 2.30 ± 0.15, and 1.87 ± 0.14 and 2.35 ± 0.15, respectively. Genotype*Location was significant (P < 0.05) for BCS, where LT cows had lower BCS (5.38 ± 0.08) than HT cows (5.83 ± 0.08) within Reidsville. However, LT-Reidsville cows were not different (P > 0.05) to HT (5.58 ± 0.08) and LT (5.64 ± 0.08) cows at Butner. The BT of HT-Reidsville cows (38.16 ± 0.24°C) was lower (P < 0.05) than that of HT-Butner (39.06 ± 0.25°C), LT-Butner (38.96 ± 0.24°C) and LT-Reidsville (39.27 ± 0.24°C) cows within week 2. Overall, BT of HT cows (38.68 ± 0.09°C) was lower (P < 0.05) than LT cows (38.89 ± 0.09°C). Genotype*Location*Week was significant (P < 0.05) for BW. In the first six weeks, LT-Reidsville cows had lower (P < 0.05) BW than all other groups. After 7 weeks, we had three distinct groups (P < 0.05), with HT-Butner having greater BW than all others, and HT-Reidsville and LT-Butner having the same BW, but greater than LT-Reidsville cows. At the end of the trial, BW averaged 578.69 ± 4.46kg, 524.76 ± 4.51kg, 551.47 ± 4.55kg, and 489.54 ± 4.76kg for HT-Butner, LT-Butner, HT-Reidsville, and LT-Reidsville cows respectively. These results suggest that animals with contrasting genetic response to FT have differences in phenotypic performance in Angus cows. We also observed a genotype-by-environmental interaction, indicating that the level of fescue toxicity might play a role in the expression of FT.
P. Khanal; K. Mayberry; M. H. Poore; D. H. Poole; N. V. Serão. 038 Effect of Genetic Response to Fescue Toxicity on Body Weight, Body Temperature, Hair Coat, Hair Shed and Body Condition Score in Angus Cows. Journal of Animal Science 2016, 95, 18 -19.
AMA StyleP. Khanal, K. Mayberry, M. H. Poore, D. H. Poole, N. V. Serão. 038 Effect of Genetic Response to Fescue Toxicity on Body Weight, Body Temperature, Hair Coat, Hair Shed and Body Condition Score in Angus Cows. Journal of Animal Science. 2016; 95 (suppl_1):18-19.
Chicago/Turabian StyleP. Khanal; K. Mayberry; M. H. Poore; D. H. Poole; N. V. Serão. 2016. "038 Effect of Genetic Response to Fescue Toxicity on Body Weight, Body Temperature, Hair Coat, Hair Shed and Body Condition Score in Angus Cows." Journal of Animal Science 95, no. suppl_1: 18-19.
Fescue toxicosis is a disease common in cattle grazing tall fescue [Lolium arundinaceum (Schreb.) Darbysh]. containing an endophytic fungus (Epichloë coenophiala) that produces ergot alkaloids. Previous research from our lab demonstrated that chronic exposure of ergot alkaloids reduced ovarian and uterine blood flow, which could alter ovarian function. Therefore, the objective of this study was to determine if ergot alkaloids from endophyte-infected tall fescue reduces follicle numbers, or suppresses follicular development resulting in poor embryo growth. Angus × Senepol heifers (n = 30) were blocked by weight and genotype [Slick (S) or Normal (N)] were placed in Calan gates then randomly assigned to receive either endophyte-infected fescue seed (EI) or non-infected fescue seed (EF; control) for 63d. Weekly measurements were collected to monitor physiological responses during exposure to ergot alkaloids. Following 30d of exposure to ergot alkaloids, heifers were synchronized and inseminated to examine reproductive measurements, including daily follicle mapping, AI pregnancy rate, and embryo development. Data were analyzed using repeated measures in the PROC MIXED procedure of SAS. ADG was decreased in EI-N heifers (0.48 kg/d) compared to other heifer groups (P < 0.05; 0.63, 0.62, 0.58 kg/d for EI-S, EF-N, and EF-S, respectively). BCS were greater for EF-S, EI-N and EI-S (5.6, 5.6 and 5.7, respectively) compared to EI-N (5.5; P < 0.05). Hair shedding scores were lower for EF-S and EI-S (1.5 and 2.2, respectively) compared to EF-N and EI-N (2.5 and 2.6, respectively; P < 0.05). The number of recruited (2-4mm) follicles was significantly greater in EI-N heifers (13.7) and significantly lower in EF-N heifers (10.6) compared to other heifer groups (P < 0.05; 11.1, 12.2 follicles for EI-S, and EF-S, respectively). No differences were observed (P > 0.05) in the number of selected (5 to 8mm) follicles. Whereas, the number of dominant (> 9mm) follicles was reduced in EI-N heifers (0.52) compared to other heifer groups (P < 0.05; 0.85, 0.87, 0.93 follicles for EI-S, EF-N, and EF-S, respectively). AI pregnancy rates were decreased in EI-N heifers (0%) compared to other heifer groups (P < 0.05; 86, 50, 43% for EI-S, EF-N, and EF-S, respectively). No differences were observed in early embryo growth and development. Based on these data, ergot alkaloids from endophyte-infected tall fescue alter ovarian follicular development, specifically during the selection to dominant stage, potentially contributing to the poor reproductive performance in infected cattle. However, the slick hair genotype appears to aid in offsetting the physiological symptoms associated with fescue toxicosis, resulting in improved pregnancy rates.
Rebecca Poole; T. L. Devine; J. C. Mackey; M. H. Poore; D. H. Poole. 040 Ergot Alkaloids from Endophyte-Infected Tall Fescue Alters Ovarian Follicle Growth and Development in Beef Heifers. Journal of Animal Science 2016, 95, 19 -20.
AMA StyleRebecca Poole, T. L. Devine, J. C. Mackey, M. H. Poore, D. H. Poole. 040 Ergot Alkaloids from Endophyte-Infected Tall Fescue Alters Ovarian Follicle Growth and Development in Beef Heifers. Journal of Animal Science. 2016; 95 (suppl_1):19-20.
Chicago/Turabian StyleRebecca Poole; T. L. Devine; J. C. Mackey; M. H. Poore; D. H. Poole. 2016. "040 Ergot Alkaloids from Endophyte-Infected Tall Fescue Alters Ovarian Follicle Growth and Development in Beef Heifers." Journal of Animal Science 95, no. suppl_1: 19-20.
Fescue toxicosis negatively impacts cattle productivity. Variation in response to endophyte-infected tall fescue within breed indicates differences in genetic tolerance to fescue toxins. The objective of this study was to determine if cattle exhibiting a short hair coat have increased tolerance to physiological symptoms associated with consuming endophyte-infected tall fescue compared to animals with longer hair coat. Purebred Angus cows, 2 to 4 yr old, at 2 locations grazed endophyte-infected tall fescue for 13 wk starting mid-April. Cattle (n = 40) were selected based on hair coat score, and designated as either slick (S) or rough (R). Weekly measurements were collected to monitor animal performance while consuming endophyte-infected tall fescue. Blood samples were collected for fescue tolerance genotyping using T-Snip. Genotype scores range from 0 to 5, with 5 being most tolerant, defined by the manufacturer. Data on hair coat score, body condition score (BCS), rectal temperature, and body weight were analyzed as repeated measures with the MIXED procedure of SAS. Frequency of T-Snip genotypes across hair groups was analyzed with a chi-square test in SAS. As expected, hair coat scores (1 to 5 scale) were significantly (P < 0.05) lower for cattle with S (1.7) compared to R hair coat (3.2). Additionally, shedding scores were lower (P < 0.05) for cattle with S (1.8) compared to R (3.6) hair coats. In 2 yr old cattle at both locations, body weight was greater (P < 0.05) in cattle with S hair coat (601.9 and 475.7 kg; location 1 and 2, respectively) compared to cattle with R hair coat (453.9 and 434.4 kg; location 1 and 2, respectively); this difference was not observed in the other age groups. In 2 yr old cattle, BCS were greater (P < 0.05) for cattle with S (5.9) compared to R (5.1) hair coats, however this difference was not observed in the other age groups. No difference (P > 0.05) was observed in rectal temperature during weekly collection days, however daily fluctuations in body temperature varied among treatment groups (P < 0.05). There was a significant (P < 0.05) deviation from the expected number of T-Snip genotypes between hair coat groups. The number of animals classified as 1, 2, and 3 for the T-Snip test was 1, 14, and 4, for S and 8, 9, and 3, for R hair coat, respectively. Based on these data, cattle with the ability to shed hair display improved productivity, a better thermoregulatory capacity and potential to be more tolerant to the negative effects associated with fescue toxicosis.
K. Mayberry; T. L. Devine; M. H. Poore; N. V. Serão; D. H. Poole. 080 Evaluation of Angus Cattle Hair Coat Length and Its Associations with Tolerance to Fescue Toxicosis. Journal of Animal Science 2016, 95, 40 -40.
AMA StyleK. Mayberry, T. L. Devine, M. H. Poore, N. V. Serão, D. H. Poole. 080 Evaluation of Angus Cattle Hair Coat Length and Its Associations with Tolerance to Fescue Toxicosis. Journal of Animal Science. 2016; 95 (suppl_1):40-40.
Chicago/Turabian StyleK. Mayberry; T. L. Devine; M. H. Poore; N. V. Serão; D. H. Poole. 2016. "080 Evaluation of Angus Cattle Hair Coat Length and Its Associations with Tolerance to Fescue Toxicosis." Journal of Animal Science 95, no. suppl_1: 40-40.
Most tall fescue in the Southeastern states contains an endophyte that causes fescue toxicosis in grazing animals, a serious disease that causes $1 billion in economic losses to the US beef industry. Recently, a new genetic test, T-Snip (AgBotanica, LCC, Columbia, MO), has been developed with the objective of identifying animals with genetic variation for fescue toxicosis tolerance. The aim of this study was to ascertain the accuracy of this new genetic test. Over 13 wk, weekly body weight (BW) data were collected on 148 pregnant purebred Angus cows at 2 locations (Butner and Reidsville, NC) where infected fescue was the only source of feed. Blood cards were collected in every animal for genotyping for T-Snip. This test provides 2 scores: tolerance index and rating, ranging from 0 to 50 and 0 to 5 respectively, with lower scores representing less tolerant animals. In our data, a total of 33, 89, 25, and 2, had ratings of 1, 2, 3, and 4, respectively. Tolerance index averaged 13.2, 21.1, 29.6, and 36, for ratings 1, 2, 3, and 4, respectively. At the end of the trial, average weekly gain (AWG) was calculated as the slope of the linear regression of BW on weeks. AWG was analyzed in a model including the fixed effects of location, parity, and initial body weight (covariate), and the random additive genetic effect (3-generation pedigree with 2,532 animals) in ASReml4. Pre-adjusted phenotypes (AWG* = additive genetic + residuals) were used for subsequent analysis. The accuracy of the T-Snip was determined using Spearman's rank correlation between AWG* with both T-Snip scores in R. This was done in 3 scenarios: all animals, and only animals in each location separately. Correlations between AWG* and T-Snip scores using all animals were −0.002 and 0.01 for the tolerance index and rating, respectively. For one location (Butner) correlations were positive low, with 0.34 (index), and 0.36 (rating). However, at Reidsville, correlations were negative low, with −0.29 (index), and −0.23 (rating). Interestingly, levels of toxic fescue are historically higher at Reidsville compared to Butner, which contrasts with results obtained in this study assuming a high accuracy of this genetic test for fescue toxicosis. Thus, these results suggest that the T-Snip test does not accurately identify animals with genetic potential for response to fescue toxicosis in Angus cows. Studies using other breeds are needed to test the accuracy of this test in different breeds.
J. M. Galliou; P. Khanal; K. Mayberry; M. H. Poore; D. H. Poole; N. V. Serão. 113 Evaluating the Accuracy of a New Commercial Genetic Test for Response to Fescue Toxicosis in Cattle. Journal of Animal Science 2016, 95, 55 -56.
AMA StyleJ. M. Galliou, P. Khanal, K. Mayberry, M. H. Poore, D. H. Poole, N. V. Serão. 113 Evaluating the Accuracy of a New Commercial Genetic Test for Response to Fescue Toxicosis in Cattle. Journal of Animal Science. 2016; 95 (suppl_1):55-56.
Chicago/Turabian StyleJ. M. Galliou; P. Khanal; K. Mayberry; M. H. Poore; D. H. Poole; N. V. Serão. 2016. "113 Evaluating the Accuracy of a New Commercial Genetic Test for Response to Fescue Toxicosis in Cattle." Journal of Animal Science 95, no. suppl_1: 55-56.
Anti-Müllerian hormone (AMH) produced by granulosa cells has previously been proposed to play a role in regulating granulosa cell differentiation and follicle selection. Although AMH receptor type II (AMHR2) dimerizes with a type I receptor to initiate AMH signaling, little is known about the regulation of AMHR2 expression in bovine granulosa cells and the role of AMH in follicle development. The primary objectives of this study were to: (1) characterize AMHR2 expression in granulosa cells during follicle development; (2) identify factors that regulate AMHR2 mRNA expression in granulosa cells; and (3) examine the role of AMH signaling in granulosa cell differentiation and proliferation. Bovine granulosa cells were isolated from 5- to 8-mm follicles before selection and deviation, as well as from 9- to 12-mm and 13- to 24-mm follicles after selection. Analyses revealed that expression of AMHR2 was greater in 5- to 8-mm follicles compared with 13- to 24-mm follicles (P < 0.05). Granulosa cells treated with bone morphogenetic protein 6 (BMP6) or BMP15, but not BMP2, significantly increased AMHR2 expression when compared with control cultured cells (P < 0.05). In addition, expression of AMH was greater in granulosa cells cultured with BMP2, BMP6, or BMP15 when compared with controls (P < 0.05). Finally, treatment with recombinant human AMH, in vitro, inhibited CYP19A1 expression in a dose-related (10-100 ng/mL) fashion, and reduced granulosa cell proliferation at 48 and 72 hours (P < 0.05). Results from these studies indicate that AMH signaling plays a role in both regulating granulosa cell proliferation and preventing granulosa cells from 5- to 8-mm follicles from undergoing premature differentiation before follicle selection.
Daniel H. Poole; Olga M. Ocón-Grove; Alan L. Johnson. Anti-Müllerian hormone (AMH) receptor type II expression and AMH activity in bovine granulosa cells. Theriogenology 2016, 86, 1353 -1360.
AMA StyleDaniel H. Poole, Olga M. Ocón-Grove, Alan L. Johnson. Anti-Müllerian hormone (AMH) receptor type II expression and AMH activity in bovine granulosa cells. Theriogenology. 2016; 86 (5):1353-1360.
Chicago/Turabian StyleDaniel H. Poole; Olga M. Ocón-Grove; Alan L. Johnson. 2016. "Anti-Müllerian hormone (AMH) receptor type II expression and AMH activity in bovine granulosa cells." Theriogenology 86, no. 5: 1353-1360.
Stockpiled tall fescue can provide adequate winter forage for beef cattle, although unsupplemented replacement heifers may display marginal performance before breeding. The objective of this study was to determine if protein supplementation and/or additional forage improves growth and reproductive performance of replacement heifers grazing stockpiled fescue. Cattle averaging 272 ± 1.59 kg were stratified by BW and then randomly assigned to 1 of 4 plots within a pasture replication. Treatment combinations were assigned in a 2 × 2 factorial arrangement and included 1) a conservative forage allocation (“normal,” targeting 85% forage use) and mineral supplement (normal forage allocation with mineral supplement [FM]), 2) normal forage allocation with protein tub (FT), 3) more liberal forage allocation (“extra,” targeting 70% forage use) and mineral supplement (extra forage allocation with mineral supplement [EM]), and 4) “extra forage allocation with protein tub (ET). Treatments were administered for 8 wk from early November to early January. Heifers were fed fescue hay for 1 wk before breeding in late January. Heifers were synchronized with the 7-d CO-Synch + controlled internal drug release device protocol and inseminated in late January. Heifers were checked for pregnancy by ultrasonography at 35 and 90 d after AI. Main and interaction effects between the 2 treatments were determined. Total supplement intake was greater for protein tub than mineral supplement (0.36 vs. 0.11 kg·heifer–1·d–1, respectively; P < 0.0001), and the additional dietary protein in the tub groups resulted in greater serum urea N concentrations (P < 0.0001; 8.15 vs. 10.4 mg/dL for mineral and protein tub, respectively). Forage utilization efficiency was greater for normal than extra forage allocation (74.7 vs. 65.8%, respectively; P < 0.0001). Main effects of both treatments on ADG were significant (P < 0.0001; 0.28, 0.43, 0.43, and 0.51 kg·heifer–1·d–1 for FM, FT, EM, and ET, respectively). There was an interaction effect of the 2 treatments on change in BCS (P < 0.05; 0.12, 0.10, 0.18, and 0.31 for FM, FT, EM, and ET, respectively). Reproductive tract scores, pelvic area, and AI pregnancy rates were not different between treatments (P > 0.05). Overall, feeding a protein supplement or providing extra forage increased gain and interacted to increase BCS but did not have an effect on reproductive performance. Supplementing with protein and providing extra forage are strategies that can increase gain in heifers, which could aid heifers in reaching puberty before estrous synchronization. Copyright © 2016. American Society of Animal Science.
S. E. Lyons; A. D. Shaeffer; M. E. Drewnoski; M. H. Poore; D. H. Poole. Effect of protein supplementation and forage allowance on the growth and reproduction of beef heifers grazing stockpiled tall fescue1. Journal of Animal Science 2016, 94, 1677 -1688.
AMA StyleS. E. Lyons, A. D. Shaeffer, M. E. Drewnoski, M. H. Poore, D. H. Poole. Effect of protein supplementation and forage allowance on the growth and reproduction of beef heifers grazing stockpiled tall fescue1. Journal of Animal Science. 2016; 94 (4):1677-1688.
Chicago/Turabian StyleS. E. Lyons; A. D. Shaeffer; M. E. Drewnoski; M. H. Poore; D. H. Poole. 2016. "Effect of protein supplementation and forage allowance on the growth and reproduction of beef heifers grazing stockpiled tall fescue1." Journal of Animal Science 94, no. 4: 1677-1688.
Cow-calf production within the Southeastern U.S. includes small to medium systems that incorporate low levels of management inputs. Implementing more intensive management across the region has been difficult to achieve due to environmental, economic and social pressures. Toxic tall fescue is part of the problem in that it is tolerant to overgrazing and is well suited to a heavy hay feeding system. There is great potential for improved forage yield and utilization efficiency through better fertility and grazing management, and by the introduction of complimentary alternative forages. One positive attribute of tall fescue is it's potential as stockpiled forage for winter grazing. Intensive winter strip-grazing is a practice that takes relatively little grazing management expertise and fence infrastructure so it is a good practice to get producers started with more intensive grazing. Winter strip-grazing can result in high forage utilization efficiency, and while cow-calf and yearling gains may be restricted, increased animal carrying capacity with comparable breeding rate appears to favor intensive utilization. However, problems with fescue toxicosis are common, and management systems that mitigate this problem will be important to future improvement of fescue-based systems. The toxins present in endophyte-infected tall fescue have a myriad of effects, with many of the more severe problems related to constriction of blood vessels and reduced blood flow in most tissues studied. Strategies to manage fescue toxicosis include both animal focused and agronomic solutions. Each have potential, but a combination of the two approaches will likely be needed. Non-toxic endophyte infected fescue is being gradually adopted with varying success, but many areas are not well suited to renovation. It has been long known that using heat tolerant cattle such as Bos Indicus breeds or Senepol imparts some tolerance to fescue, but because of market forces, using these breeds is not well accepted in much of the fescue region. Recently the discovery of the “slick hair gene” in Senepol and other tropical breeds allows the potential for inserting this trait into cattle with highly desirable growth and meat quality. Many farmers in the Mid-Atlantic region are interested in local finishing systems for beef. High prices for local beef and a resurgence of small processors areas have stimulated these production systems. Finishing a significant portion of calves requires major structural changes to the farm system to improve post-weaning performance and to balance forage availability.
M. H. Poore; D. H. Poole. 127 Potential for more intensive Cow-Calf production in the Southeast Region. Journal of Animal Science 2016, 94, 62 -62.
AMA StyleM. H. Poore, D. H. Poole. 127 Potential for more intensive Cow-Calf production in the Southeast Region. Journal of Animal Science. 2016; 94 (suppl_1):62-62.
Chicago/Turabian StyleM. H. Poore; D. H. Poole. 2016. "127 Potential for more intensive Cow-Calf production in the Southeast Region." Journal of Animal Science 94, no. suppl_1: 62-62.
Fescue toxicosis is a disease common in cattle grazing tall fescue (Festuca arundinacea) containing an endophytic fungus (Epichloë coenophiala) that produces ergot alkaloids. Ergot alkaloids cause vasoconstriction to the extremities, however it remains undetermined how blood flow to the reproductive organs are affected. Therefore, the objective of this study was to determine if ergot alkaloids from endophyte-infected fescue reduces blood flow to the reproductive organs thus hindering reproductive functions. Angus heifers (n=36) naïve to ergot alkaloids 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 75d. Weekly measurements were taken to monitor the heifer’s growth and performance. Reproductive measurements, including ovarian structures, diameter of uterine (UT) and ovarian (OV) artery and veins, and hormone analysis were collected after 30d of exposure to ergot alkaloids. Following estrous synchronization, ovarian measurements and blood samples were taken at 0, 5, 10 and 17 d of the estrous cycle. Data were analyzed using repeated measure in the PROC MIXED procedure of SAS. Average daily gain was decreased for the EI group (0.8 kg/d) compared to EF heifers (1.0 kg/d; P0.05). Vasoconstriction occurred in the caudal artery, but not the caudal vein, of heifers exposed to the EI fescue seed (P<0.05). No differences were observed in antral follicle counts or CL area. Circulating progesterone concentrations tended to be lower in EI heifers compared to EF heifers (P<0.1). Vasoconstriction occurred in the UT artery (P<0.05; 109 vs. 80.6 cm2 for EF, and EI, respectively) and UT vein (P<0.05; 116.9 vs. 93.1 cm2 for EF, and EI, respectively) of heifers exposed to the EI fescue seed from d 10 through 17 of the estrous cycle. Likewise, there was a significant decrease in OV artery (P<0.05; 15.8 vs. 12.0 cm2 for EF, and EI, respectively) and OV vein (P<0.05; 18.6 vs. 13.6 cm2for EF, and EI, respectively) diameter in the mid to late estrous cycle. This reduction in blood flow to the reproductive organs during the critical period of maternal recognition of pregnancy may contribute to the reduced pregnancy rates associated with fescue toxicosis. Copyright © 2016. American Society of Animal Science.
D. H. Poole; S. E. Lyons; J. C. Mackey; A. M. Tyson; G. Shaeffer; M. H. Poore. 060 Ergot alkaloid induced vasoconstriction of bovine uterine and ovarian blood vessels. Journal of Animal Science 2016, 94, 29 -30.
AMA StyleD. H. Poole, S. E. Lyons, J. C. Mackey, A. M. Tyson, G. Shaeffer, M. H. Poore. 060 Ergot alkaloid induced vasoconstriction of bovine uterine and ovarian blood vessels. Journal of Animal Science. 2016; 94 (suppl_1):29-30.
Chicago/Turabian StyleD. H. Poole; S. E. Lyons; J. C. Mackey; A. M. Tyson; G. Shaeffer; M. H. Poore. 2016. "060 Ergot alkaloid induced vasoconstriction of bovine uterine and ovarian blood vessels." Journal of Animal Science 94, no. suppl_1: 29-30.
Most tall fescue (Festuca arundinacea) is infected with a fungal endophyte (Epichloë coenophiala) that produces ergot alkaloids; hindering reproductive success by decreasing pregnancy rates and suppressing progesterone (P4) concentrations. The objective of this study was to determine if progesterone supplementation following timed AI or embryo transfer (ET) increases pregnancy rates (PR) of cattle consuming endophyte-infected tall fescue. Nulliparous and multiparous cattle were maintained on stockpiled endophyte-infected tall fescue. All cattle were synchronized using the standard 7d CO-Synch +CIDR® program. Cattle were inseminated 60-66 hr post-CIDR removal for TAI. In the ET group, cattle received either a fresh or frozen embryo on day 10 post- CIDR removal. Cattle received either a CIDR blank (control) or active CIDR ten d post-CIDR removal. Pregnancy and embryo area were determined by ultrasonography at d 30 of gestation. Data was analyzed using a PROC GLIMMIX procedure of SAS and examined for effects of treatment, year, location, and age. Statistical significance was determined at P < 0.05 and a tendency at 0.050.05) or nulliparous cattle (P4-41.7% vs. control-41.7%; P>0.05). However, PR in heifers receiving P4 supplementation tended to differ by location (location1- 43.3% vs. location2 - 71.7%). There was a significant effect of year (P7 yrs old (P4-98.7% vs. control-57.2%; P0.05). However, supplemental P4 tended to increase pregnancy rates in Angus cattle receiving embryos (P4-43.8% vs. control-17.6%; P<0.10), but was not observed in crossbred cattle. Additional progesterone did not affect embryo area in either the TAI or ET groups. While progesterone supplementation throughout maternal recognition of pregnancy significantly increased PR in cattle receiving embryos in year 1, it did not show significant impact in year 2 or following TAI in cattle consuming endophyte-infected tall fescue for both years.
J. C. Mackey; T. L. Devine; A. M. Tyson; M. H. Poore; D. H. Poole; P. M. Kennedy. 034 Impact of Progesterone Supplementation on Pregnancy Rates Following Timed AI or Embryo Transfer in Beef Cattle Consuming Endophyte-Infected Fescue. Journal of Animal Science 2016, 94, 17 -17.
AMA StyleJ. C. Mackey, T. L. Devine, A. M. Tyson, M. H. Poore, D. H. Poole, P. M. Kennedy. 034 Impact of Progesterone Supplementation on Pregnancy Rates Following Timed AI or Embryo Transfer in Beef Cattle Consuming Endophyte-Infected Fescue. Journal of Animal Science. 2016; 94 (suppl_1):17-17.
Chicago/Turabian StyleJ. C. Mackey; T. L. Devine; A. M. Tyson; M. H. Poore; D. H. Poole; P. M. Kennedy. 2016. "034 Impact of Progesterone Supplementation on Pregnancy Rates Following Timed AI or Embryo Transfer in Beef Cattle Consuming Endophyte-Infected Fescue." Journal of Animal Science 94, no. suppl_1: 17-17.
Fescue toxicosis impacts cattle consuming endophyte-infected tall fescue (Festuca arundinacea) resulting in substantial economic losses annually to the beef industry. Symptoms of this disease include increased respiration and body temperature, retained winter hair coat and vasoconstriction. Originally identified in Senepol cattle, the slick gene creates for short, slick hair and cattle that more effectively regulates body temperature. Therefore, the objective of this study was to determine if cattle expressing the slick gene have increased tolerance to physiological symptoms associated with ergot alkaloids from endophyte-infected tall fescue. Angus × Senepol heifers (n=31) were blocked by weight and hair type, (Slick; S or Normal; N) and placed in Calan gates then randomly assigned to receive either endophyte-infected fescue haylage (E+) or non-infected fescue haylage (E-; control) for 63d. Weekly measurements were collected to monitor physiological responses during exposure to ergot alkaloids. Data were analyzed using repeated measure in the PROC MIXED procedure of SAS. Average daily gain was decreased in E+N heifers (0.48 kg/d) compared to other heifer groups (P0.05); however blood pressure decreased in E+ heifers compared to E- heifers (P0.05) across all groups. Although no difference was observed in rectal temperature during weekly collection days, daily fluctuations in body temperature varied among treatment groups. As expected, skin surface temperature was increased E+N heifers (38.1oC) compared to other heifer groups (P<0.05; 37.1, 37.2 and 36.8 oC for E+S, E-N, and E-S, respectively). Hair coat scores (1-5 scale) were significantly lower for E-S and E+S (1.7 and 2.2, respectively) compared to E-N and E+N (2.9 and 3.1, respectively; P<0.05). Additionally, shedding scores were lower for E-S and E+S (1.5 and 2.2, respectively) compared to E-N and E+N (2.5 and 2.6, respectively; P<0.05). Based on these data, incorporating the slick hair phenotype in to cattle may be advantageous to help offset some of the negative effects associated with fescue toxicosis.
T. L. Devine; J. C. Mackey; G. Shaeffer; M. H. Poore; D. H. Poole. 077 Hair Coat Phenotype in Heifers Alters Physiological Responsiveness to Ergot Alkaloids Commonly Found in Endophyte-Infected Tall Fescue. Journal of Animal Science 2016, 94, 38 -38.
AMA StyleT. L. Devine, J. C. Mackey, G. Shaeffer, M. H. Poore, D. H. Poole. 077 Hair Coat Phenotype in Heifers Alters Physiological Responsiveness to Ergot Alkaloids Commonly Found in Endophyte-Infected Tall Fescue. Journal of Animal Science. 2016; 94 (suppl_1):38-38.
Chicago/Turabian StyleT. L. Devine; J. C. Mackey; G. Shaeffer; M. H. Poore; D. H. Poole. 2016. "077 Hair Coat Phenotype in Heifers Alters Physiological Responsiveness to Ergot Alkaloids Commonly Found in Endophyte-Infected Tall Fescue." Journal of Animal Science 94, no. suppl_1: 38-38.
The use of fixed-time artificial insemination (FTAI) provides producers with numerous benefits including the use of superior genetics, shorter breeding and calving seasons, and a more uniform calf crop. However, the cost of implementing FTAI protocols is one of the several drawbacks hindering their use in the beef industry. Potential injection-site lesions from intramuscular injections of the hormones necessary for estrus synchronization are also a cause of concern for carcass quality. The objectives of this experiment were to (1) determine whether or not a twice-used controlled internal drug release (CIDR) device would be effective in an FTAI protocol without adversely affecting pregnancy rate and (2) whether or not the subcutaneous administration of PGF2α affects pregnancy rate. Nulliparous females (n = 99) between 13 and 27 months of age and multiparous cows (n = 43) between 48 and 74 months of age were synchronized for estrus using the 7-day CO-Synch + CIDR protocol. The females were randomly assigned to one of the two treatments: (1) a once-used CIDR (control) or (2) a twice-used CIDR device (treatment) incorporated into their synchronization protocol. The females were also randomly assigned to have their injection of PGF2α administered either intramuscularly or subcutaneously. Blood was taken in a random subset of nulliparous females (n = 52) just before device removal and assayed for concentration of progesterone. The concentration of progesterone was higher (P = 0.01) in the animals that received once-used CIDR devices than that in those received twice-used CIDR devices (3.4 ± 0.5 and 1.4 ± 0.5 ng/mL, respectively). There was no significant effect of parity (P = 0.82), artificial insemination technician (P = 0.60), PGF2α administration (P = 0.83), or treatment (P = 0.67) on pregnancy rates to artificial insemination which were 75.4 ± 6.0% and 71.7 ± 6.4%, for animals that received once- and twice-used CIDR devices, respectively. This study provides evidence that although concentration of progesterone is decreased in animals treated with a twice-used CIDR device, there is still a sufficient release of progesterone from the device to effectively synchronize estrus without adversely affecting the fertility of a herd.
A.M. Muth-Spurlock; D.H. Poole; C.S. Whisnant; Press Enter Key For Correspondence Information. Comparison of pregnancy rates in beef cattle after a fixed-time AI with once- or twice-used controlled internal drug release devices. Theriogenology 2015, 85, 447 -451.
AMA StyleA.M. Muth-Spurlock, D.H. Poole, C.S. Whisnant, Press Enter Key For Correspondence Information. Comparison of pregnancy rates in beef cattle after a fixed-time AI with once- or twice-used controlled internal drug release devices. Theriogenology. 2015; 85 (3):447-451.
Chicago/Turabian StyleA.M. Muth-Spurlock; D.H. Poole; C.S. Whisnant; Press Enter Key For Correspondence Information. 2015. "Comparison of pregnancy rates in beef cattle after a fixed-time AI with once- or twice-used controlled internal drug release devices." Theriogenology 85, no. 3: 447-451.
A growing body of literature provides evidence of a prominent role for bone morphogenetic proteins (BMPs) in regulating various stages of ovarian follicle development. Several actions for BMP6 have been previously reported in the hen ovary, yet only within postselection (preovulatory) follicles. The initial hypothesis tested herein is that BMP6 increases FSH receptor (FSHR) mRNA expression within the granulosa layer of prehierarchal (6–8 mm) follicles (6–8 GC). BMP6 mRNA is expressed at higher levels within undifferentiated (1–8 mm) follicles compared with selected (≥9 mm) follicles. Recombinant human (rh) BMP6 initiates SMAD1, 5, 8 signaling in cultured 6–8 GC and promotes FSHR mRNA expression in a dose-related fashion. In addition, a 21 h preculture with rhBMP6 followed by a 3 h challenge with FSH increases cAMP accumulation, STAR (StAR) expression, and progesterone production. Interestingly, rhBMP6 also increases expression of anti-Müllerian hormone (AMH) mRNA in cultured 6–8 GC. This related BMP family member has previously been implicated in negatively regulating FSH responsiveness during follicle development. Considering these data, we propose that among the paracrine and/or autocrine actions of BMP6 within prehierarchal follicles is the maintenance of both FSHR and AMH mRNA expression. We predict that before follicle selection, one action of AMH within granulosa cells from 6 to 8 mm follicles is to help suppress FSHR signaling and prevent premature granulosa cell differentiation. At the time of selection, we speculate that the yet undefined signal directly responsible for selection initiates FSH responsiveness. As a result, FSH signaling suppresses AMH expression and initiates the differentiation of granulosa within the selected follicle.
O. M. Ocón-Grove; D. H. Poole; A. L. Johnson. Bone morphogenetic protein 6 promotes FSH receptor and anti-Müllerian hormone mRNA expression in granulosa cells from hen prehierarchal follicles. REPRODUCTION 2012, 143, 825 -833.
AMA StyleO. M. Ocón-Grove, D. H. Poole, A. L. Johnson. Bone morphogenetic protein 6 promotes FSH receptor and anti-Müllerian hormone mRNA expression in granulosa cells from hen prehierarchal follicles. REPRODUCTION. 2012; 143 (6):825-833.
Chicago/Turabian StyleO. M. Ocón-Grove; D. H. Poole; A. L. Johnson. 2012. "Bone morphogenetic protein 6 promotes FSH receptor and anti-Müllerian hormone mRNA expression in granulosa cells from hen prehierarchal follicles." REPRODUCTION 143, no. 6: 825-833.
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; 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. Copyright © 2011. American Society of Animal Science.
C. L. Pickworth; S. C. Loerch; S. G. Velleman; J. L. Pate; D. H. Poole; F. L. Fluharty. Adipogenic differentiation state-specific gene expression as related to bovine carcass adiposity1. Journal of Animal Science 2011, 89, 355 -366.
AMA StyleC. L. Pickworth, S. C. Loerch, S. G. Velleman, J. L. Pate, D. H. Poole, F. L. Fluharty. Adipogenic differentiation state-specific gene expression as related to bovine carcass adiposity1. Journal of Animal Science. 2011; 89 (2):355-366.
Chicago/Turabian StyleC. L. Pickworth; S. C. Loerch; S. G. Velleman; J. L. Pate; D. H. Poole; F. L. Fluharty. 2011. "Adipogenic differentiation state-specific gene expression as related to bovine carcass adiposity1." Journal of Animal Science 89, no. 2: 355-366.