Use of Saccharomyces cerevisiae-based products and effects on rumen environment and performance of sheep subjected to dietary changes

ABSTRACT: Natural additives in ruminant diet optimizes animal performance by controlling or modifying the rumen fermentation pattern. The aim of this study was to evaluate the effects of using Saccharomyces cerevisiae products during abrupt changes in dietary starch concentration on ruminal pH maintenance, performance and metabolism of confined sheep. Twenty adult ewes, crossbred Texel x Corriedale(44.7±6.97 Kg BW) were divided into three groups: Control (n=6), Cultron X (yeast culture; n=7) and Cultron Pro (hydrolyzed yeast; n=7), administered at a dose of 5 g/sheep/day (10x1010CFU/g DM). The experiment lasted 20 days divided into four periods, alternating between 40 and 60% concentrate. Blood and ruminal fluid were collected at the end of each period, and daily dry matter intake was measured to determine the average daily gain (ADG). Blood tests included blood count and biochemical parameters such as glucose, urea, total plasma proteins (TPP), liver enzymes, acute phase proteins and minerals. There was an upward trend in ADG in group Cultron X compared to control in period 3. Although, ruminal pH did not differ between groups, protozoan motility was higher in animals supplemented with hydrolyzed yeast. The Cultron Pro group showed an increase in TPP in periods 3 and 4, and AST in periods 2 and 3 compared to the control group. There was no difference in other metabolites. Yeast supplementation is a potential tool in times of feeding challenge, in which yeast culture is the most effective for improving performance of confined sheep being in improving performance of confined sheep.

摘要：反刍动物日粮中的天然添加剂可通过调控或改变瘤胃发酵模式，优化动物生产性能。本研究旨在评估日粮淀粉浓度骤变期间，使用酿酒酵母（Saccharomyces cerevisiae）产品对舍饲绵羊瘤胃pH维持、生产性能及代谢水平的影响。选取20只特克塞尔×考力代杂交成年母羊，初始体重为(44.7±6.97 kg，将其分为3组：对照组（n=6）、Cultron X组（酵母培养物，n=7）及Cultron Pro组（水解酵母，n=7），每日给药剂量为5 g/只/天（10×10^10 CFU/g 干物质（DM））。本试验为期20天，分为4个阶段，精料占比在40%与60%交替更换。在每个阶段结束时采集血液及瘤胃液，并测定每日干物质采食量，以计算平均日增重（ADG）。血液检测指标包括血常规及生化指标，如葡萄糖、尿素、血浆总蛋白（TPP）、肝脏酶类、急性期蛋白及矿物质。在第3阶段，Cultron X组的平均日增重较对照组呈上升趋势。尽管各组间瘤胃pH无显著差异，但饲喂水解酵母的受试动物的原虫运动性更高。与对照组相比，Cultron Pro组在第3、4阶段的血浆总蛋白水平升高，第2、3阶段的天冬氨酸氨基转移酶（AST）活性升高。其余代谢指标无显著差异。在饲喂应激阶段，酵母添加是一种潜在的应对策略，其中酵母培养物对提升舍饲绵羊生产性能的效果最为显著。