Mellor D J, Murray L
Res Vet Sci. 1982 Mar;32(2):177-80.
Fifteen ewes were fed at between 0.6 and 0.8 times the recommended rates in order to reproduce the liveweight changes observed in Scottish Blackface sheep on hill farms. The curved crown-rump length (CRL) of individual fetuses was measured daily between 90 and 142 days of gestation and fetal dimensions and placental weight were measured at 142 days. Fetal growth rate decreased progressively from about 5.9 mm per day between 90 and 111 days of gestation to about 3.6 mm per day by 130 days. At 142 days of gestation the placental weight and the fetal CRL, girth and weight were all significantly lower than in fetuses of well fed ewes. The mechanisms responsible for the reduction in fetal growth rate after 111 days of gestation and the implications for animals on hill farms are discussed.
15只母羊按照推荐饲养量的0.6至0.8倍进行喂养，以重现苏格兰黑脸羊在山地农场观察到的体重变化。在妊娠90至142天期间，每天测量单个胎儿的曲顶臀长（CRL），并在142天时测量胎儿尺寸和胎盘重量。胎儿生长速率从妊娠90至111天期间的约每天5.9毫米逐渐下降至130天时的约每天3.6毫米。在妊娠142天时，胎盘重量以及胎儿的CRL、周长和体重均显著低于喂养良好的母羊所产胎儿。本文讨论了妊娠111天后胎儿生长速率降低的机制以及对山地农场动物的影响。
