Inclusion of live yeast and mannan-oligosaccharides in high grain-based diets for sheep: Ruminal parameters, inflammatory response and rumen morphology

The objective of this study was to evaluate the effects of dietary supplementation with live yeast (Saccharomyces cerevisiae), mannan-oligosaccharides and the combination of these additives on the inflammatory response, ruminal parameters and rumen morphology of sheep fed a high grain-based diet. Thirty-Two Dorper x Santa Ines crossbred lambs with an average weight of 24±2 kg were distributed in a completely randomized design. The animals were housed in individual stalls and fed ad libitum. Diet treatments were: Control (without additive); LY (2 g/kg DM of live yeast, Saccharomyces cerevisiae), MOS (2 g/kg DM of mannan-oligosaccharides) and LY+MOS (2 g/kg DM of LY + 2 g/kg DM of MOS). The experiment lasted 42 days. The supplementation with MOS alone and the additives combination resulted in increased ruminal pH (P3) concentration in the rumen decreased (P3 concentrations and LPS translocation into the bloodstream. Diets containing MOS and LY+MOS enhanced the health of the ruminal epithelium by reducing the thickness of the stratum corneum, and diets containing LY and LY+MOS decreased the incidence and severity of hepatic abscesses.本研究旨在评估日粮添加活性酵母（Saccharomyces cerevisiae，酿酒酵母）、甘露寡糖（mannan-oligosaccharides，MOS）以及二者联合添加对饲喂高精粮日粮绵羊的炎症反应、瘤胃参数及瘤胃形态的影响。选取32只平均体重为24±2 kg的杜泊×圣伊内斯杂交肉羊，采用完全随机设计进行分组。试验羊单栏饲养并自由采食。日粮处理组分为：对照组（无添加剂）、LY组（每千克干物质[Dry Matter，DM]添加2 g活性酵母，即酿酒酵母）、MOS组（每千克干物质添加2 g甘露寡糖）以及LY+MOS组（每千克干物质添加2 g活性酵母与2 g甘露寡糖）。试验周期为42天。单独添加MOS与联合添加两种添加剂可提高瘤胃pH值，同时降低瘤胃内脂多糖（Lipopolysaccharide，LPS）浓度，进而减少脂多糖向血液循环的易位。添加MOS与LY+MOS组日粮可通过降低角质层厚度改善瘤胃上皮健康；而添加LY与LY+MOS组日粮可降低肝脓肿的发生率与严重程度。