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.

中文翻译：

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检查麦角生物碱对小母牛胎儿发育和随后的生长和繁殖性能的长期影响


食用有毒内生真菌感染的高羊茅 （EI） 会导致家畜的繁殖性能不佳。在这项研究中，目的是评估妊娠中期（妊娠第 93 天至第 188 天）麦角瓦林暴露对母牛性能、生长中的雌性胎儿以及妊娠暴露的小母牛犊随后的生长和繁殖性能的影响。怀孕的安格斯奶牛和西门塔尔-安格斯奶牛按年龄 （2 至 3 岁、至 7 岁和 >7 y）、体重 （BW） 和品种进行封闭;然后随机分配放牧新型内生真菌感染的高羊茅（EN;<5% 感染率;n = 27 第 1 年，n = 16 第 2 年）或毒性 EI（99% 感染率;n = 27 第 1 年，n = 17 第 2 年）。从 2017 年 4 月中旬至 7 月（第 1 年）和 2018 年（第 2 年）收集每周体重、身体状况评分 （BCS）、毛发评分、脱发评分 （HSS） 和黄体酮分析血样 （P4）。测量妊娠长度、出生体重、胎盘特征、小母牛犊生长、青春期开始、卵巢特征和人工授精妊娠率。使用 SAS 的 MIXED 程序分析数据。与 EN 牧场上的奶牛相比，在 EI 牧场放牧的奶牛平均日增重降低，BCS 降低，HSS 增加，P4 浓度降低 （P < 0.01）。母牛在妊娠中期暴露于 EI 牧场的小母牛出生体重降低 （P < 0.01）。在研究的任一年，小母牛怀孕率均不受妊娠期间 EI 牧草暴露的影响。然而，在 2 年观察到 EI 暴露小母牛的妊娠率存在逐年处理效应;第 2 年暴露 EI 的小母牛在其中两次授精中提高了怀孕率。 综合起来，这些数据强化了妊娠期间食用有毒 EI 会对母系和后代的性能产生负面影响。需要更多的研究来评估更多的参数，以阐明妊娠期间麦角瓦林暴露可能对终生产生的影响。