Antioxidant action in diets with ground soybeans on ruminal microbial production, digestion, and fermentation in buffaloes

ABSTRACT The objective of this study was to evaluate the effect of adding ground soybeans and antioxidants to diet of buffaloes on intake, ruminal microbial production, total and ruminal digestibility of nutrients, and ruminal fermentation parameters. Four crossbred buffaloes with a mean weight of 506±29 kg were distributed in a 4×4 Latin square. Four diets were tested: control; diet with ground soybeans; diet with ground soybeans and supplementation with yerba mate; and diet with ground soybeans and supplementation with yerba mate and vitamin E. The addition of ground soybeans had negative effects on intake of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber, as well as ruminal digestibility of neutral detergent fiber and total carbohydrates but did not influence total digestibility of nutrients. Yet, the ground soybeans diet increased the concentration of butyrate and microbial production in the rumen. The diet with ground soybeans supplemented with yerba mate decreased the concentration of acetate and increased the concentration of propionate and increased the efficiency of synthesis and the production of microbial protein in the rumen. There was a positive additive effect of vitamin E in the presence of yerba mate, enhancing the synthesis and production efficiency of microbial protein. Thus, the addition of ground soybeans and antioxidants to diet of buffaloes improves the efficiency of microbial protein synthesis and increases the production of butyrate, without, in general, altering the total digestibility of nutrients.

摘要 本研究旨在探究在水牛日粮中添加磨碎大豆与抗氧化剂，对其采食量、瘤胃微生物生成量、养分总消化率与瘤胃消化率，以及瘤胃发酵参数的影响。选取4头平均体重为506±29 kg的杂交水牛，采用4×4拉丁方试验设计。共设置4种试验日粮：空白对照组、仅添加磨碎大豆的日粮、添加磨碎大豆并补充马黛茶（yerba mate）的日粮，以及添加磨碎大豆、补充马黛茶与维生素E的日粮。磨碎大豆的添加会显著降低干物质、有机物、粗蛋白质、中性洗涤纤维与酸性洗涤纤维的采食量，同时降低中性洗涤纤维与总碳水化合物的瘤胃消化率，但对养分总消化率无显著影响。然而，饲喂添加磨碎大豆的日粮可提升瘤胃内丁酸浓度与微生物生成量。饲喂添加磨碎大豆并补充马黛茶的日粮，可降低瘤胃内乙酸浓度，同时提升丙酸浓度，并提高瘤胃微生物蛋白质的合成效率与生成量。在添加马黛茶的基础上补充维生素E可产生正向叠加效应，进一步提升微生物蛋白质的合成效率与生成量。综上，在水牛日粮中添加磨碎大豆与抗氧化剂，可提升微生物蛋白质合成效率并增加丁酸生成量，且总体上不会改变养分的总消化率。