日粮纤维的物理有效性对奶牛咀嚼活动、瘤胃发酵、产奶性能的影响

Effects of dietary physical availability fiber on chewing,rumen fermentation and milk production performance in dairy cows

本研究旨在评估以水稻秸秆和木薯为粗饲料的日粮纤维物理有效性对奶牛泌乳性能、咀嚼活性、瘤胃发酵和养分消化率的影响。试验选择8头泌乳期荷斯坦杂交奶牛,随机分为两组,分别饲喂两种日粮。平衡日粮水稻秸秆、木薯和浓缩料的比例,使两种日粮中中性洗涤纤维物理有效性分别为15.5%和20.2%。结果:低纤维物理有效性组较高纤维物理有效性组显著提高了奶牛中性洗涤纤维和酸性洗涤纤维摄入量(P<0.05),相反,高纤维物理有效性组奶牛非纤维碳酸化合物摄入量较高(P<0.05)。高纤维有效性组较低纤维有效性组显著降低了粗脂肪消化率(P<0.05)。日粮中性洗涤纤维物理有效性对奶牛瘤胃发酵特性和咀嚼活动无显著影响(P>0.05)。结论:日粮纤维高水平物理有效性在不影响瘤胃发酵的情况下可以改善乳成分,但如果考虑饲料成本而大量使用木薯粉时,日粮配方需要考虑中性洗涤纤维的物理有效性。

The purpose of this study was to evaluate the effects of dietary fiber physical effectiveness on lactation performance,masticatory activity,rumen fermentation and nutrient digestibility of dairy cows fed with rice straw and cassava.Eight Holstein hybrid cows with lactation period were randomly divided into two groups and fed with two diets.By balancing the proportion of rice straw,cassava and concentrate in the two diets,the physical effectiveness of neutral detergent fibers in the two diets was 15.5%and 20.2%,respectively.Results:the intake of neutral and acidic detergent fibers in the group with low fiber physical availability was significantly increased in the group with high fiber physical availability(P<0.05),while the intake of non-fiber carbonates in the group with high fiber physical availability was higher(P<0.05).The digestibility of crude fat was significantly lower in the high fiber availability group than in the low fiber availability group(P<0.05).The physical availability of dietary neutral detergent fibers had no significant effect on rumen fermentation characteristics and chewing activities in cows(P>0.05).Conclusion:high levels of physical availability of dietary fiber can improve milk composition in dairy cows without affecting rumen fermentation,but if cassava is used in large quantities due to feed costs,the dietary formula needs to consider the physical availability of neutral detergent fiber.