Abstract Ruminal acidosis can penalize cattle performance and modify ruminal microbiota composition; in that sense, providing quality forage may be a useful tool to cope with such dysfunction. This assay aimed to control animals’ performance and assess ruminal microbiota shifts and interactions when fattening Holstein bulls are fed corn-based concentrate and different quality forages. Thirty animals (from 119 to 332 d of age and from 164 to 511 kg body weight [BW]) were fed corn-based concentrate and were allotted to three experimental treatments or forage sources: barley straw, considered as control (Hordeum vulgare, CTR), oats haylage (Avena sativa, OATS) or vetch haylage (Vicia sativa, VETCH). Both concentrate and forage were supplied ad libitum in a free choice system and animals had free access to drinking water. Bulls’ BW and concentrate intake were automatically recorded on a daily basis. Feces and ruminal fluid were sampled twice, during the growing period (158 d of age and 220 kg BW) and during the finishing period (280 d of age and 434 kg BW), for digestibility, ruminal fermentation and microbial population characterization. No differences in concentrate intake or BW could be detected between CTR and OATS-fed animals; however, VETCH-fed bulls had lower concentrate intake (P

中文翻译：

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不同饲草来源的精饲料饲喂荷斯坦公牛的营养利用效率、瘤胃发酵和微生物群落

摘要 瘤胃酸中毒会影响牛的生产性能并改变瘤胃微生物群组成；从这个意义上说，提供优质草料可能是应对此类功能障碍的有用工具。该测定旨在控制动物的表现并评估在育肥荷斯坦公牛饲喂玉米浓缩物和不同质量草料时瘤胃微生物群的变化和相互作用。将 30 只动物（119 至 332 天龄和 164 至 511 公斤体重 [BW]）喂食以玉米为基础的浓缩物，并分配到三种实验处理或饲料来源：大麦秸秆，作为对照（大麦，CTR )、燕麦干草 (Avena sativa, OATS) 或野豌豆干草 (Vicia sativa, VETCH)。精料和草料都在自由选择系统中随意供应，动物可以自由获得饮用水。每天自动记录公牛的体重和精矿摄入量。在生长期（158 天龄和 220 kg BW）和育肥期（280 天龄和 434 kg BW）期间对粪便和瘤胃液进行两次采样，用于消化率、瘤胃发酵和微生物种群特征。在 CTR 和 OATS 喂养的动物之间没有检测到浓缩物摄入量或 BW 的差异；然而，VETCH 喂养的公牛的精料摄入量较低（P 在 CTR 和 OATS 喂养的动物之间没有检测到浓缩物摄入量或 BW 的差异；然而，VETCH 喂养的公牛的精料摄入量较低（P 在 CTR 和 OATS 喂养的动物之间没有检测到浓缩物摄入量或 BW 的差异；然而，VETCH 喂养的公牛的精料摄入量较低（P