Item No. 1 of 1

INVESTIGATOR: Duckett, S.

PERFORMING INSTITUTION:
CLEMSON UNIVERSITY
CLEMSON, SOUTH CAROLINA 29634

IMPACT OF FESCUE TOXICOSIS ON FETAL DEVELOPMENT AND POSTNATAL GROWTH

NON-TECHNICAL SUMMARY: Tall fescue is the primary cool season perennial grass utilized in the eastern US and the majority of tall fescue contains an endophyte, which produces compounds (ergot alkaloids) toxic to grazing livestock but beneficial to the plant. Tall fescue toxicosis is a major forage and livestock issue that seriously impacts animal production causing over $1 billion in production losses. Our hypothesis is that exposure to these toxins during gestation reduces fetal growth and subsequent postnatal growth of the offspring. We will conduct two main experiments that will: 1) determine how exposure to these toxins at specific times of gestation alter fetal growth and development, and 2) examine the impact of these toxins on fetal growth, lactation, and subsequent postnatal growth. The completion of this research will allow us to establish when tall fescue exposure is most critical to fetal growth and development. The results will be used to develop alternative management strategies for ruminants that can decrease the impact of tall fescue on fetal growth and increase lifetime production efficiency.

OBJECTIVES: The long-term goal of this research is to develop a greater understanding of the in utero effects of ergot alkaloids in order to mitigate their impact on ruminant animal production efficiency and quality.

APPROACH: Our hypothesis is that exposure to ergot alkaloids during gestation reduces fetal growth due to vasoconstriction and/or placental insufficiency, which negatively impacts secondary muscle fiber development, postnatal growth, carcass quality, and production efficiency of these offspring. We will conduct two main experiments that will: 1) determine how ergot alkaloid exposure during specific times of gestation alter fetal development, placentation, vasoconstriction, and secondary muscle fiber development, and 2) examine the impact of ergot alkaloids fed during critical periods of gestation on fetal growth, lactation, and subsequent postnatal growth.

PROGRESS: 2015/04 TO 2019/03
Target Audience:The target audience reached by our research project was livestock producers and extension agents in southeastern US in field days and workshops, and fellow scientists in the US and internationally at American Society of Animal Science and Reciprocal Meat Conference. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Andrae, J., C. Roberts, M. Poore, and G. Pent. 2018. Fescue Toxicosis: A Brief Overview. Presented at Blackstone VA, Mt. Ulla NC, Newberry SC, Calhoun GA, Mt. Vernon MO, and Princeton KY as a portion of a day long workshop to approximately 400 producers. March 11-20, 2019. Workshops were sponsored and organized by Alliance for Grassland Renewal. Andrae J. G. and S. K. Duckett. 2019. Impact of fescue toxicosis on fetal development and postnatal growth. Clemson Veterinary Continuing Education Conference, Clemson SC, February 24, 2019. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

IMPACT: 2015/04 TO 2019/03
What was accomplished under these goals? Two experiments were conducted to examine the impact of fescue toxicosis on fetal development and postnatal growth. Suffolk ewes (n = 36 in expt. 1; n = 60 in expt. 2) were fed endophyte-infected (E+; 1.77 mg hd-1 d-1 ergovaline and ergovalinine) or endophyte-free (E-; 0 mg hd-1 d-1 ergovaline and ergovalinine) tall fescue seed at equal amounts in a total mixed ration during two stages of gestation (MID, d 35 - 85 / LATE, d 86 - 133). In experiment 1, terminal surgeries were conducted on d 133 of gestation to assess changes in placental function and fetal development at similar gestational ages. In experiment 2, ewes went to term and changes in milk production, lamb birth weight, and lamb postnatal growth were examined. Experiment 1: Feeding endophyte-infected tall fescue seed (E+) during MID and LATE gestation induces fescue toxicosis in pregnant ewes as indicated by suppressed prolactin levels and elevated excretion of urinary ergot alkaloids. Our results indicate that exposure to ergot alkaloids during LATE (d 86 - 133) gestation has the greatest impact on placental development by lowering uterine and placentome weights; which reduced total fetal weight per ewe by 15% in ewes fed E+ seed during LATE gestation (E-/E+ and E+/E+). Exposure to E+ fescue seed during LATE gestation appears to stunt development of the placenta, likely due to the vasoconstrictive effects of ergot alkaloids, during an especially crucial stage of gestation when placental remodeling and the majority of fetal growth occurs. The effect of feeding toxic endophyte-infected seed resulted in a suppression of vasoactivity in both the maternal and fetal sides. This suppression of vasoactivity associated with ergot alkaloid exposure combined with the sensitivity of the umbilical artery are indications of vasoconstriction occurring on the fetal side. Feeding E+ seed to dams during LATE gestation (E-/E+ and E+/E+) produced smaller fetuses with higher brain to empty body weight ratio. This confirms that E+ fescue exposure, specifically during LATE gestation (d 85 - 133), results in the development of intrauterine growth restricted (IUGR) fetuses. These reductions in fetal development altered skeletal muscle fiber formation and miRNA expression associated with cytokine signaling and the Jak-STAT pathway. Future research is needed to investigate mechanisms by which ergot alkaloids disrupt normal developmental processes as well as strategies that can be employed to mitigate these disruptions. Experiment 2: Feeding endophyte-infected tall fescue seed (E+) during MID and LATE gestation induces fescue toxicosis in pregnant ewes as indicated by suppressed prolactin levels and elevated excretion of urinary ergot alkaloids. Exposure to E+ tall fescue seed during LATE gestation reduced gestation length (-1.4 d), lamb birth weight (-12%), and lamb weaning weight (-14%). Early milk production in ewes fed E+ tall fescue seed during MID and LATE gestation was reduced by over 40% compared to E- seed. At weaning, ewe lambs were moved to endophyte-free tall fescue pastures and supplemented to achieve weight gains of 200 g/d and wethers were individually fed high concentrate diet ad libitum to market weight (55 kg). Ewe lambs born to dams fed E+/E+ seed remained lighter in weight and took longer to reach puberty. Wether lambs born to dams fed E+/E+ seed had higher gains and reached market weight at similar ages compared to wethers from E- dams. Feed efficiency, carcass weight or meat quality in wethers was not altered by exposure to ergot alkaloids fed during gestation. Exposure to E+ seed during late gestation significantly reduced early milk production, lamb birth and weaning weight. Ewe lambs born to E+/E+ dams continued to have delayed growth rates post-weaning and later puberty attainment; however, wethers born to E+/E+ dams were able to compensate post-weaning and achieve similar gains, feed efficiency, carcass and meat quality when finished on concentrates ad libitum. In summary, ergot alkaloid exposure from feeding endophyte-infected tall fescue seed (E+) during gestation suppresses vasoactivity and sensitivity of the umbilical artery, which demonstrates that vasoconstriction was occurring. Exposure to E+ fescue seed during late gestation appears to stunt development of the placenta during an especially crucial stage of gestation when placental remodeling and the majority of fetal growth occurs. This produces smaller fetuses with higher brain to empty body weight ratio, which confirms intrauterine growth restriction (IUGR). Exposure to E+ seed during mid and late gestation reduced early milk production in the ewes and lamb weaning weights. The ability of these E+ offspring to compensate for lower birth and weaning weight depends on energy content of the growing/finishing diet.

PUBLICATIONS (not previously reported): 2015/04 TO 2019/03
1. Type: Journal Articles Status: Published Year Published: 2019 Citation: Britt, J. L., M. F. Miller Jr., B. M. Koch, J. Klotz, G. Aiken, S. L. Pratt, N. M. Long, J. R. Strickland, J. G. Andrae, F. N. Schrick, R. Powell, T. Bruce and S. K. Duckett. 2019. Ergot alkaloid exposure during gestation alters: 1. Maternal characteristics and placental development of pregnant ewes. Journal of Animal Science, skz068, https://doi.org/10.1093/jas/skz068
2. Type: Journal Articles Status: Published Year Published: 2019 Citation: Klotz, J., J. L. Britt, M. F. Miller Jr., M. A. Snider, G. E. Aiken, N. M. Long, S. L. Pratt, J. G. Andrae, and S. K. Duckett. 2019. Ergot alkaloid exposure during gestation alters: 2. Uterine and umbilical artery vasoactivity. Journal of Animal Science, skz069, https://doi.org/10.1093/jas/skz069
3. Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Greene, M. A., J. L. Britt, R. R. Powell, F. A. Feltus, W. C. Bridges Jr., T. Bruce, J. L. Klotz, M. F. Miller Jr., and S. K. Duckett. 2019. Ergot alkaloid exposure during gestation alters: 3. Fetal growth, muscle fiber development and miRNA transcriptome. J. Anim. Sci. (In revision).
4. Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Andrae, J. G., J. L. Britt, M. F. Miller Jr., J. Klotz, G. Aiken, and S. K. Duckett. 2018. Impact of prenatal tall fescue toxicosis on ewe milk production and postnatal lamb growth. AFGC Proceedings, http://www.afgc.org/proceedings/2018/.
5. Type: Journal Articles Status: Under Review Year Published: 2019 Citation: Britt, J. L., R. R. Powell, C. McMahan and S. K. Duckett. 2019. Ergot alkaloids present in endophyte-infected tall fescue seed alter the microscopic morphology of the ovine placenta. Placenta (In author review).
6. Type: Journal Articles Status: Under Review Year Published: 2019 Citation: Britt, J. L. and S. K. Duckett. 2019. Consumption of tall fescue seed containing ergot alkaloids during gestation alters the cotyledon transcriptome in the ovine placenta. Placenta (In author review).
7. Type: Journal Articles Status: Under Review Year Published: 2019 Citation: Britt, J. L., M. A. Greene, S. A. Wilbanks, G. Aiken, J. L. Klotz, W. C. Bridges Jr., J. G. Andrae, F. N. Schrick, M. F. Miller Jr. and S. K. Duckett. 2019. Impact of feeding endophyte-infected tall fescue seed to ewes during mid and/or late gestation on milk production, lamb birth weight and and postnatal growth. J. Anim. Sci. (In author review).

PROGRESS: 2017/04/01 TO 2018/03/31
Target Audience:Presentations were given to livestock producers throughout the Southeastern US and also to scientists at professional meetings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?In July 2017, seven abstracts were submitted and presentations made at the Annual Meeting of the American Society of Animal Science. An abstract was also submitted and presented at the American Forage and Grasslands Council in January 2018. Several presentation were made to livestock producers in SC and the southern region on the results of these studies. Six abstracts were submitted to American Society of Animal Science for presentation at the 2018 Annual Meeting. What do you plan to do during the next reporting period to accomplish the goals?Several journal and extension articles are in progress and will be submitted for publication. We are finalizing all analyses on the puberty attainment in the ewe lambs, and muscle fiber typing and miRNA in the muscles from the wethers. We will continue to present our results to the scientific community and to producers. The results from both experiments are conclusive that exposure to toxic (E+) fescue during late gestation has a negative impact on milk production, and birth weight, weaning weight, and postnatal growth of their offspring.

IMPACT: 2017/04/01 TO 2018/03/31
What was accomplished under these goals? Two experiments were conducted to examine the impact of fescue toxicosis on fetal development and postnatal growth. In Experiment 1, pregnant Suffolk ewes (n =32) were randomly assigned to two fescue treatments of endophyte-infected tall fescue seed (E+; 1772 ug of ergovaline + ergovalinine/hd/d) or endophyte-free tall fescue seed (E-; 0 ug of ergovaline + ergovalinine/hd/d) fed at two stages of gestation (MID, d 35 to 85 or LATE, d 85 to 133) in a 2 x 2 factorial arrangement of treatments. Ewes were fed individually the same amount of a total mixed ration and fescue seed on a daily basis to d 133 of gestation. Maternal and fetal necropsies were performed at d 133 of gestation. Body weight gain was reduced in ewes fed E+ during LATE gestation. The reduced body weight was likely related to lower dry matter intake of these E-/E+ ewes due to increased refusals after switching to the E+ treatment in LATE gestation. Ewes fed E+ LATE had reduced placentome weights by 24%. Fetal lamb weight at d 133 of gestation was reduced by 10% in ewes fed E+ during LATE gestation. Fetal muscle mass was reduced, and changes in muscle fiber type and miRNA were also observed. Feeding E+ seed during MID gestation did not alter placenta weights, fetal lamb weight, or muscle mass. Exposure to E+ fescue significantly reduced placental and fetal weights when fed during LATE gestation. In Experiment 2, pregnant Suffolk ewes (n = 60) were genotyped for the dopamine receptor 2 (DRD2) single nucleotide polymorphism (SNP g270a). Ewes were stratified by genotype (AA, AG, GG) to two fescue treatments of endophyte-infected tall fescue seed (E+; 1772 ug of ergovaline + ergovalinine/hd/d) or endophyte-free tall fescue seed (E-; 0 ug of ergovaline + ergovalinine/hd/d) fed at two stages of gestation, MID (d 35 to 85) or LATE (d 85 to 133) in a 3 x 2 x 2 factorial arrangement of treatments. Ewes were fed individually the same amount of a total mixed ration and fescue seed on a daily basis to parturition. Gestation length was shorter (-2.9 d) for ewes fed E+ fescue seed during LATE gestation. Lamb birth weight was reduced by 10% for ewes fed E+ fescue seed during LATE gestation. Lamb birth weight was higher by 10% for GG ewes compared to AA or AG; however, there was no interaction between genotype and fescue treatment for birth weight. Milk production during the first two days of lactation was reduced by 50% in ewes fed E+ fescue seed during LATE gestation. Milk production at d 21 of lactation was lower in ewes fed E+ seed in MID gestation. Lambs from ewes fed E+ during LATE gestation had lower weaning weights. There was an interaction bewteen ewe genotype and fescue treatment for average daily gain from birth to weaning. Lambs born to GG ewes that were fed E+/E+ fescue seed had lower growth rates than lambs from GG ewes from other fescue treatments. Overall, feeding E+ seed to ewes during late gestation reduced lamb birth and weaning weight, and greatly reduced early milk production. After weaning, ewe lambs (n = 38) grazed non-fescue pastures and were supplemented with a commercial sheep feed to achieve weight gains of about 200 g/d. Blood samples were also collected weekly to assess puberty attainment. At d 126 post-weaning, ewe lambs from ewes fed E+ during LATE tended to be lighter than ewe lambs from E- LATE ewes. Yearling weights did not differ by fescue treatment. Progesterone analyses are on-going and will be used to assess when ewe lambs reached puberty. Wethers were individually fed a complete grower diet to 41 kg and then switched to a finisher diet to 59 kg BW or 185 d on feed post weaning. Wethers were slaughtered at the Clemson University Meat Lab and weights were obtained for the pelt, head, brain, organs, digestive tract, and hot carcass weight. At 24 h postmortem, carcasses were split into two sides and weights obtained. Individual muscles were dissected from the left side and weighed, and total lean and fat was removed from the right side and was ground for proximate composition. Differences in digestive tract weights and feed efficiency were observed for fescue treatment by ewe genotype. Lambs from GG ewes fed E-/E+ fescue had heavier reticulum, rumen, and large intestine weights and the shortest number of days to the final live weight endpoint. Feed efficiency was also improved in the growing phase for these lambs. Additional analyses are on-going to assess chemical composition, tenderness, miRNA and muscle fiber type differences in these lambs. Maternal consumption of ergot alkaloids during gestation negatively impacts post-weaning growth and efficiency in their offspring.

PUBLICATIONS: 2017/04/01 TO 2018/03/31
1. Type: Conference Papers and Presentations Status: Accepted Year Published: 2018 Citation: Andrae, J. G., J. L. Britt, M. F. Miller Jr., J. Klotz, G. Aiken, and S. K. Duckett. 2018. Impact of prenatal tall fescue toxicosis on ewe milk production and postnatal lamb growth. American Forage and Grasslands Council (AFGC) Proceedings, http://www.afgc.org/proceedings/2018/.
2. Type: Other Status: Submitted Year Published: 2018 Citation: Britt, J. L., S.K. Adams, M. F. Miller Jr., C. J. Kojima, J. Andrae, and S. K. Duckett. Impact of ergot alkaloids fed during mid to late gestation on mammary development and lactation. J. Anim. Sci. (Abstr.; submitted).
3. Type: Other Status: Submitted Year Published: 2018 Citation: Britt, J. L., R. R. Powell, C. L. McMahan, T. F. Bruce, and S. K. Duckett. Placental histology using H&E and Ki67 after exposure to ergot alkaloids during mid and late gestation. J. Anim. Sci. (Abstr.; submitted).
4. Type: Other Status: Submitted Year Published: 2018 Citation: Greene, M. A., J. L. Britt, M. F. Miller Jr., S. K. Adams, B. M. Koch, and S. K. Duckett. Impacts of ergot alkaloid exposure during mid and late gestation on wether preformance and glucose, insulin and NEFA values. J. Anim. Sci. (Submitted).
5. Type: Other Status: Submitted Year Published: 2018 Citation: Britt, J. L., M. F. Miller Jr., S.K. Adams, M. Greene, J. Andrae, and S. K. Duckett. Impact of ergot alkaloids fed during mid to late gestation on postnatal growth and puberty attainment in ewe lambs. J. Anim. Sci. (Abstr.; submitted).
6. Type: Other Status: Submitted Year Published: 2018 Citation: Greene, M. A., J. L. Britt, M. F. Miller Jr., S. K. Adams, B. M. Koch, and S. K. Duckett. Impacts of ergot alkaloid exposure during mid and late gestation on maternal glucose, insulin and NEFA concentrations, and performance of their offspring. J. Anim. Sci. (Abstr.; submitted).
7. Type: Other Status: Submitted Year Published: 2018 Citation: Miller Jr., M. F., J. L. Britt, J. G. Andrae, and S. K. Duckett. Prenatal and postnatal lamb muscle growth as influenced by ergot alkaloid exposure in utero. Reciprocal Meat Conference, AMSA, (Abstr.; submitted).

PROGRESS: 2016/04/01 TO 2017/03/31
Target Audience:Presentations were given to livestock producers throughout the Southeastern United States and also to scientists at professional meetings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Presentations were given at the Southern Section of Animal Science Meeting, American Forage and Grasslands Council Meeting, and six abstracts are submitted for presentation at American Society of Animal Science meeting this summer. Numerous presentations have been given to livestock producers in the SC on the effects of fescue toxicosis on fetal development. What do you plan to do during the next reporting period to accomplish the goals?Experiment 2 is currently in progress and will be completed in the fall of 2017. Results from experiment 2 will be analyzed and presented.

IMPACT: 2016/04/01 TO 2017/03/31
What was accomplished under these goals? Experiment 1: Suffolk ewes (n = 36) were synchronized and bred to a single ram. Ewes (BW 78.02 ± 9.53 kg) identified by ultrasound at d 35 to be pregnant and with twin fetuses were fed endophyte-infected tall fescue seed (E+; 1772 µg/hd/d ergovaline+ergovalinine) or endophyte-free tall fescue seed (E-; 0 µg/hd/d ergovaline+ergovalinine) during the two gestational time periods (d 35-85 or d 86-133). This created four unique dietary treatments E+/E+, E+/E-, E-/E+, and E-/E-. Ewes were pair-fed to maintain similar DMI. Maternal and fetal necropsies were performed at d133 of gestation. Data was analyzed as a randomized block design with a 2x2 factorial with treatment (E+ or E-) , time of gestation (d 35-85 or d 86-133), and two-way interaction in the model. There was no significant difference in placental or overall fetal weight based on d 35 - d 85 treatment (P > 0.41). Ewes receiving E+ treatment between d 86 - d 133 had lower uterine weights (P = 0.003) and lower total placentome weights (P = 0.0005). Cotyledon and caruncle tissue weights were reduced in ewes on E+ treatment between d 86 - d 133 compared to E- treatment (P < 0.002). Cotyledon weights were reduced by 25% and caruncle weights were reduced by 19% . Ergot alkaloid exposure during late gestation may induce uteroplacental insufficiency and lead to reduced fetal growth. Feeding ergot alkaloids during early gestation did not alter (P > 0.05) fetal BW, muscle or organ weights. Feeding ergot alkaloids during late gestation reduced fetal BW at d 133 of gestation by 10% compared to E- treatment. Thoracic circumference was smaller (P < 0.05) for E+ fetuses than E-; crown-rump length and abdominal circumference also tended (P < 0.10) to be smaller for E+ fetuses. Total muscle weight was reduced (P < 0.05) by 13% in fetuses from ewes fed E+ seed during late gestation. Weights of the psoas major, semitendinosus, semimembranosus, and quadriceps femoris were lighter (P < 0.05) for fetuses from ewes fed E+ seed during late gestation. Weight of the heart and liver were lighter (P < 0.05) for fetuses from ewes fed E+ seed during late gestation. There were interactions (P < 0.10) between fescue treatment and time of gestation for kidney, pancreas, spleen, and brain weights. Brain weight expressed on a fetal BW basis was higher (P = 0.01) in fetuses from ewes fed E+ fescue seed indicating asymmetrical fetal growth. Feeding endophyte-infected seed containing ergovaline + ergovalinine during late gestation (d 86-133) reduces fetal growth and muscle mass. Ewes receiving E+/E+ and E-/E+ treatments had decreased vasoactivity in umbilical arteries to serotonin with a dextral shift in concentrations where the response curve initiated (P< 0.05). Interestingly, uterine arteries were not responsive to exposure to ergotamine or ergovaline, whereas umbilical arteries were very responsive. Umbilical arteries collected from ewes receiving E-/E- and E+/E- were more vasoactive to ergot alkaloids (P<0.05). Maternal blood supply to the placenta seems protected from the negative effects of ergot alkaloids; however, umbilical vasculature is not and could negatively affect fetal growth. RNA-Seq. of cotyledon placental tissue showed numerous miRNA transcripts were upregulated (P < 0.01; n = 15) in E+E+ compared to E-E- and included miR-21, miR-221, miR-99a, miR-152, miR-381, miR-30a, miR-143, and miR-122. miR-21 exhibited a 9.89-fold increase in expression level for E+E+ treatment compared to E-E-. miR-21 has previously been implicated as a potential biomarker for fetal hypoxia due to upregulation in both placental and plasma/serum samples. Numerous genes were upregulated (P = < 0.01; n = 131) in E+E+ compared to E-E- and included genes involved in angiogenesis and vasoconstriction (FGA, APOH, HPX), hemostasis and coagulation (KNG1, FGA, PLG, FGB), oxidative reduction (PYROXD2, CYP2E1), cholesterol import and lipoprotein particles (APOC3, APOH, APOA2, GC, PON1), cell activation (FGA), and immune response (KNG1, AHSG). Several genes were down regulated (P < 0.01; n = 56) in E+E+ compared to E-E- and included genes involved in fatty acid metabolism, lipid oxidation, and beta-oxidation (ADIPOQ), G-protein coupled receptor (GPR151), signal transduction (HRH4), and cell proliferation (PODN). The consumption of ergot alkaloids during gestation directly effects the mRNA expression in cotyledon tissues. MicroRNA sequencing of the semitendinous muscle showed known MyomiR (miR-1, miR133a, miR133b, miR206, miR-208b, miR-486, miR-499) in skeletal muscle were present in our samples but not (P > 0.05) differentially expressed due to treatment. miR-148b, miR-300-3p, miR-431-3p, miR-299-3p, and miR-541-5p were up-regulated (P < 0.05) in E+/E+ compared to E-/E- fetal ST muscles. miR-652, miR-628, miR-2427, miR-22-3p, miR-8118-p5, miR-376d, and miR-677 were down-regulated (P < 0.05) in E+/E+ versus E-/E-. Skeletal muscle miR-148b has been shown to reduce glucose uptake in response to insulin in humans. miR-541 promotes vascular smooth muscle cell proliferation. Exposure to ergot alkaloids in utero alters miRNA expression in fetal skeletal muscle. Experiment 2: Suffolk ewes were synchronized in groups weekly (n = 15/group; 5 groups) using a 7-d CIDR protocol followed by PGF2α and mated to a single mature ram. The ram was fitted with a marking harness to estimate breeding date. Pregnancy was confirmed via transrectal ultrasound at d 35. Pregnant ewes (n = 60 ewes) were randomly allotted to four dietary treatments of a total mixed ration containing: 1) E- seed fed from d 35 to parturition [E-/E-], 2) E+ seed fed from d 35 to 85 and E- seed fed d 86 to parturition [E+/E-], 3) E- seed fed from d 35 to 85 and E+ seed fed d 86 to parturition [E-/E+], or 4) E+ seed fed from d 35 to parturition [E+/E+}. Endophyte-free (E-; 0.0 μg ergovaline + ergovalinine/g diet DM) and endophyte-infected (E+; Neotyphodium coenophialum; 0.8 μg ergovaline + ergovalinine/g diet DM) tall fescue seed was analyzed for ergot alkaloid levels according to Aiken et al. (2009) and diets formulated to provide the targeted levels of ergovaline & ergovalinine in the diet [1772 ug/hd/d for E+]. Fescue seed was delivered daily in a total mixed ration (corn, cottonseed hulls, soybean meal, seed) that was formulated to meet NRC requirements for pregnant ewes at each stage of gestation. Ewes were individually fed to deliver the dose of ergot alkaloids to each ewe and monitor feed intake. Ewes were pair-fed so that feed intake was similar across treatments. Color Doppler ultrasonography was performed using a Classic Medical TeraVet 3000 Ultrasound Unit (Classic Universal Ultrasound, Tequesta, FL) with a 12L5-VET (12 MHz) linear array transducer. Cross-sectional area of the left carotid arteries were measured for each ewe to determine luminal area, and a Power Doppler image was collected for measuring peak systolic and end diastolic velocities, heart rate, and pulsatility and resistance indices. Luminal areas were similar (P > 0.5) between E-E- (28.8 ± 1.98 mm2) and E+E- (30 ± 1/85 mm2) treatments, and between E+E+ (17.0 ± 2.06 mm2) and E-E+ (17.5 ± 2.06 mm2). Carotid arteries with E-E- and E+E- treatments were relaxed in comparison to those with the E+E+ and E-E+ treatments. Although there were no treatment effects (P > 0.10) on peak systolic and end diastolic velocities or heart rate, pulsatility and resistance indices were greater (P < 0.05) for E+E+ and E-E+ than for E-E- and E+E- treatments. Results indicated a vasoconstrictive response of the carotid arteries in pregnant ewes exposed to ergot alkaloids, but vascular recovery was demonstrated for sheep that had been switched from E+ to E- diets. Currently, we are in the middle of lambing and data collection process for this experiment.

PUBLICATIONS: 2016/04/01 TO 2017/03/31
1. Type: Other Status: Accepted Year Published: 2017 Citation: Britt, J. L, M. F. Miller Jr., B. M. Koch, N. M. Long, S. L. Pratt, J. G. Andrae, and S. K. Duckett. Effects of ergot alkaloids during mid-late gestation on uteroplacental Sufficiency and Fetal Growth. J. Anim. Sci. 95 (Suppl. 1):29 (Abstr.)
2. Type: Other Status: Submitted Year Published: 2017 Citation: Aiken, G. E., J. G. Andrae, J. L. Britt, M. F. Miller Jr., S. K. Adams, and S. K. Duckett. Vasoconstrictive responses of the carotid artery in pregnant ewes to ergot alkaloid exposure. J. Anim. Sci. 95 (Suppl. 1): submitted (Abstr.).
3. Type: Other Status: Submitted Year Published: 2017 Citation: Miller, Jr., M. F., F. A. Feltus, J. L. Britt, B. M. Koch, and S. K. Duckett. Changes in fetal muscle miRNA expression from exposure to ergot alkaloids in utero. J. Anim. Sci. 95 (Suppl. 1): submitted (Abstr.).
4. Type: Other Status: Submitted Year Published: 2017 Citation: Miller Jr., M. F. J. L. Britt, B. M. Koch, N. M. Long, J. G. Andrae, S. L. Pratt, and S. K. Duckett. Effects of fescue toxicosis at different stages of gestation on fetal development. J. Anim. Sci. 95 (Suppl. 1):submitted (Abstr.).
5. Type: Other Status: Submitted Year Published: 2017 Citation: Britt, J. L, F. A. Feltus, M. F. Miller Jr., B. M. Koch, M. C. Miller, and S. K. Duckett. Altered mRNA expression in placental tissues of ewes exposed to ergot alkaloids during gestation. J. Anim. Sci. 95 (Suppl. 1):submitted (Abstr.).
6. Type: Other Status: Other Year Published: 2017 Citation: Britt, J. L., F. A. Feltus, M. F. Miller Jr., B. M. Koch, M. C. Miller, and S. K. Duckett. Altered expression of placental miRNA in ewes with uterplacental insufficiency due to consumption of endophyte-infected tall fescue seed. J. Anim. Sci. 95 (Suppl. 1):submitted (Abstr.)
7. Type: Other Status: Submitted Year Published: 2017 Citation: Klotz, J. L., M. F. Miller Jr., J. L Britt, M. A. Snider, G. E. Aiken, N. M. Long, S. L. Pratt, J. G. Andrae, and S. K. Duckett. Effects of ergot alkaloid ingestion during gestation on maternal and fetal vasoactivity. J. Anim. Sci. 95 (Suppl. 1):submitted (Abstr.).
8. Type: Other Status: Accepted Year Published: 2017 Citation: Andrae, J. G., J. L. Britt, M. F. Miller Jr., S. L. Pratt, and S. K. Duckett. Impact of fescue toxicosis during mid to late gestation on fetal growth. Am. Forage and Grasslands Council Conference Proceedings, available at: http://www.afgc.org/proceedings/2017/

PROGRESS: 2015/04/01 TO 2016/03/31
Target Audience:Currently, we are conducting experiment one that will determine how ergot alkaloid exposure at specific times of gestation alter fetal development, placentation, vasoconstriction, and secondary muscle fiber formation. The target audience at this time is the scientific community. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This research project has provided many opportunities for training of graduate (n = 3) and undergraduate (n = 10) students assisting with the project. Graduate and undergraduate students have learned about feeding of the ewes, blood and urine collection, ultrasound assessment of pregnancy, and maternal and fetal tissue sample collection. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?We are still in the data collection phase of the experiment. Once the necropsies and sample analyses are completed, we will submit abstracts for presentation at scientific meetings and generate extension bulletins to distribute to livestock producers.

IMPACT: 2015/04/01 TO 2016/03/31
What was accomplished under these goals? Currently, we are in the process of completing experiment one to determine how ergot alkaloid exposure at specific times of gestation alter fetal development, placentation, vasoconstriction, and secondary muscle fiber formation. Fifty commercial ewes that were naive to tall fescue were purchased for this study. Ewes were synchronized and exposed to one ram. Pregnant ewes were randomly allotted to one of four dietary treatments of total mixed ration containing: 1) endophyte-free tall fescue seed [E-; 0.0 μg ergovaline + ergovalinine/g diet DM] from d 35 to 135, 2) endophyte-infected [Neotyphodium coenophialum] tall fescue seed [E+; 0.8 μg ergovaline + ergovalinine/g diet DM] from d 35 to 85 and E- seed from d 86 to 135, 3) E- seed from d 35 to 85 and then E+ seed from d 86 to 135, and 4) E+ seed fed from d 35 to 135. Maternal and fetal necropsy are conducted at d 135 of gestation and samples of maternal and fetal tissues collected for subsequent analyses. At this point, we have completed necropsies on 18 ewes with 22 ewes remaining that will be completed on April 12, 2016. Then we will move into the sample analyses phase of the experiment.

PUBLICATIONS: 2015/04/01 TO 2016/03/31
No publications reported this period.