Consumption of toxic endophyte-infected tall fescue 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 - 3, 4 - 7, and > 7 y), body weight (BW), and breed; and then randomly assigned to graze either novel (EN; <5% infection rate; n = 27 Year 1, n = 16 Year 2) or toxic endophyte-infected tall fescue (EI; 99% infection rate; n = 27 Year 1, n = 17 Year 2). Weekly BW, body condition scores (BCS), hair coat scores (HCS), 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 (AI) pregnancy rates were measured. Data were analyzed using the MIXED procedure of SAS. Cows grazing EI pastures had reduced ADG, 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 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 endophyte-infected tall fescue 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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检查麦角生物碱对胎儿小母牛发育以及随后的生长和繁殖性能的长期影响


食用有毒内生菌感染的高羊茅会导致家畜繁殖性能较差。本研究的目的是评估妊娠中期（妊娠第 93 天至 188 天）暴露于麦角瓦林对母畜性能、雌性胎儿生长以及妊娠期间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 - 3、4 - 7 和 > 7 岁）、体重 (BW) 和品种进行分组；然后随机分配放牧新的（EN；％3C5％感染率；n = 27年1，n = 16年2）或有毒内生菌感染的高羊茅（EI；99％感染率；n = 27年1， n = 17 年 2)。每周体重、身体状况评分 (BCS)、毛皮评分 (HCS)、脱发评分 (HSS) 和用于黄体酮 (P4) 分析的血液样本收集自 2017 年 4 月中旬至 7 月（第一年）和 2018 年（第 1 年）。第 2 年）。测量妊娠长度、出生体重、胎盘特征、小母牛生长、青春期开始、卵巢特征和人工授精 (AI) 妊娠率。使用 SAS 的 MIXED 程序分析数据。与 EN 牧场上的奶牛相比，吃 EI 牧场的奶牛 ADG 降低，BCS 降低，HSS 更高，P4 浓度降低 (P < 0.01)。母牛在妊娠中期暴露于 EI 牧场的小母牛的出生体重有所下降 (P < 0.01)。在研究的任一年中，小母牛怀孕率均未受到妊娠期间 EI 牧场暴露的影响。然而，暴露于 EI 的小母牛在第 2 年的妊娠率出现了按年处理的效果；第二年暴露于 EI 的小母牛在两次授精中的妊娠率有所增加。 综合起来，这些数据证实，在妊娠期间食用有毒内生菌感染的高羊茅会对母鼠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，以阐明妊娠期间接触麦角瓦林可能产生的终生影响。