This study aimed to evaluate the effects of supplementing Saccharomyces cerevisiae (SC) during the pre‐ and post‐weaning periods on growth, metabolic and hormonal responses, and rumen fermentation in calves. Three‐week‐old Holstein calves were assigned to either control (n  = 12) or SC group (n  = 12), the latter of which received 2 × 10⁹ cfu/day of SC. The experiment was conducted over a period of 7 weeks around weaning. Daily gain (DG) in the SC group was higher (p < .05) than that in the control group. In the SC group, plasma glucose, insulin, and growth hormone (GH) concentrations were higher (p < .05) and concentrations of glucagon and insulin‐like growth factor 1 (IGF‐1) tended to be higher (p < .1) than in the control group. Proportion of rumen propionate and concentration of rumen ammonia nitrogen at 10 weeks of age were greater (p < .05) in the SC group than that in the control group. Supplementation of SC around weaning may improve dietary nutrient and energy availability and increase plasma GH and IGF‐1 concentrations. These changes observed in SC‐supplemented calves could be closely related to the improvement of DG.

中文翻译：

---

酿酒酵母补充剂对断奶前后荷斯坦犊牛生长性能、血浆代谢物和激素以及瘤胃发酵的影响。

本研究旨在评估在断奶前后补充酿酒酵母(SC) 对犊牛生长、代谢和激素反应以及瘤胃发酵的影响。三周大的荷斯坦小牛被分配到对照组 ( n  = 12) 或 SC 组 ( n  = 12)，后者 每天接受 2 × 10 ^{9 cfu 的 SC。}实验在断奶前后进行了 7 周。SC 组的日增重 (DG) 高于对照组 ( p < .05)。在 SC 组中，血浆葡萄糖、胰岛素和生长激素 (GH) 浓度较高 ( p <.05) 和胰高血糖素和胰岛素样生长因子 1 (IGF-1) 的浓度往往高于对照组 ( p < .1)。SC 组在 10 周龄时的瘤胃丙酸盐比例和瘤胃氨氮浓度高于对照组 ( p < .05)。在断奶前后补充 SC 可以改善膳食营养和能量的可用性，并增加血浆 GH 和 IGF-1 的浓度。在补充 SC 的小牛中观察到的这些变化可能与 DG 的改善密切相关。