| 摘要: |
| 【目的】研究不同饲喂水平活性干酵母对肉牛饲料瘤胃有效降解率和发酵相关指标的影响，为活性干酵母在肉牛生产中的应用提供依据。【方法】以3头装有永久性瘤胃瘘管的秦川肉牛为试验动物，采用3×3拉丁方设计，分为3期，每期30 d(预试期10 d，试验期20 d)，每期对3头牛分别饲喂不同水平(0，30，60 g/（d·头）)活性干酵母（混入相同的精料中饲喂），在试验第26～30天，采集瘤胃液，测定其pH及氨态氮和挥发性脂肪酸含量。采用尼龙袋法分别测定4种粗饲料（青贮玉米、苜蓿干草、小麦麦秸、酒糟）和3种蛋白饲料（豆粕、菜粕、棉粕）的干物质（DM）、粗蛋白（CP）和中性洗涤纤维（NDF）的有效降解率。【结果】活性干酵母可显著提高瘤胃液pH、挥发性脂肪酸含量和乙酸相对含量（P＜0.05），显著降低氨态氮含量和丙酸相对含量（P＜0.05），促进瘤胃乙酸型发酵。饲喂活性干酵母有助于提高苜蓿干草DM、NDF、CP，青贮玉米DM、NDF及菜粕CP的有效降解率，其中以60 g/（d·头）的饲喂量效果较好，但对其他饲料的有效降解率无显著影响。【结论】饲喂活性干酵母可显著改善瘤胃发酵相关指标，提高苜蓿干草DM、NDF、CP，青贮玉米DM、NDF及菜粕CP的有效降解率，其中以60 g/（d·头）的饲喂量效果较好。 |
| 关键词: 活性干酵母 肉牛饲料 降解速率 发酵指标 |
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| 基金项目:国家重点研发计划项目（2018YFD0501700）；国家肉牛牦牛产业技术体系项目（CARS-37） |
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| Effect of active dried yeast on rumen degradation of beef cattle diet |
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LIANG Jiaye,ZHANG Song,SONG Yu,et al
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| Abstract: |
| 【Objective】This study analyzed the effects of different feeding levels of active dry yeast on effective rumen degradation rate and fermentation related indexes of beef cattle feed to provide basis for application of active dry yeast in beef cattle production.【Method】Three Qinchuan beef cattle with permanent rumen fistula were fed on same basal diet in three periods.Each period last for 30 days with 10 days for pre trail and 20 days for experiment,and cows were fed with three yeast levels (0,30 and 60 g/(d·head)).During days 26-30,the degradation rates of dry matter (DM),crude protein (CP) and neutral detergent fiber (NDF) of four forages (corn silage,alfalfa,wheat straw,and distiller grains) and three proteins (soybean meal,rapeseed meal,and cottonseed meal) were determined by nylon bag method.The rumen pH,ammonia nitrogen and concentration of volatile fatty acids were also measured.【Result】Active dry yeast could significantly increase pH,volatile fatty acid content and relative acetic acid content of gastric tumor fluid (P<0.05),significantly reduce ammonia nitrogen content and propionic acid content (P<0.05),and promote rumen acetic acid type fermentation.Active dry yeast feeding also improved the effective degradation rates of DM, NDF and CP of alfalfa hay,DM and NDF of silage corn and CP of rape meal.The level of 60 g/(d·head) was the best,and had no significant effect on effective degradation rates of other feeds.【Conclusion】Feeding active dry yeast can significantly improve relevant indicators of rumen fermentation and improve effective degradation rates of DM,NDF and CP of alfalfa hay,DM and NDF of silage corn and of CP cabbage meal.The feed amount of 60 g/(d·head) is recommended. |
| Key words: active dry yeast beef cattle feed degradation rate fermentation indicators |
