Abstract The present study evaluated the effects of maternal undernutrition induced by a lower natural pasture allowance from 23 days before conception on the distribution and morphometry of muscle precursor cells and the expression of PCNA, Myogenin and Pax 7 in muscles Psoas major, Longissimus lumborum, Semitendinosus, Semimembranosus, Gluteobiceps and Gluteus medius of 70-day old sheep fetuses. Ewes were assigned to two nutritional treatments (complete randomized block design) beginning 23 days before conception: High pasture allowance (HPA) ewes grazed on natural grasslands at 10−12 kg dry matter (DM) /100 kg of live weight (LW)/day, while low pasture allowance (LPA) ewes grazed at 5−8 kg DM /100 kg of LW/day. On day 70 of pregnancy 18 ewes (nine/treatment) carrying single male fetuses were euthanized and samples were taken from fetal muscles. Samples were stained with hematoxylin-eosin to evaluate muscle morphology and treated with immunohistochemical methods to evaluate the expression of myogenic regulatory factors. Maternal undernutrition reduced the ratio of secondary to primary fibers (P

中文翻译：

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母体营养不良以依赖肌肉的方式影响 70 天龄绵羊胎儿的主要肌肉的继发性肌生成

摘要 本研究评估了受孕前 23 天自然放牧量减少导致的母体营养不良对肌肉前体细胞的分布和形态测定以及 PCNA、肌细胞生成素和 Pax 7 在肌肉腰大肌、腰最长肌、半腱肌中表达的影响。 、 70 日龄羊胎儿的半膜肌、臀二头肌和臀中肌。母羊在受孕前 23 天开始接受两种营养治疗（完全随机区组设计）： 在天然草地上以 10-12 千克干物质 (DM)/100 千克活重 (LW)/天，而低放牧量 (LPA) 母羊以 5-8 千克干物质/100 千克 LW/天放牧。在怀孕的第 70 天，对 18 只怀有单雄性胎儿的母羊（9 只/治疗）实施安乐死，并从胎儿肌肉中取样。样品用苏木精-伊红染色以评估肌肉形态，并用免疫组织化学方法处理以评估生肌调节因子的表达。母亲营养不良降低了次生纤维与初级纤维的比率（P