To better understand rumen adaptation during dietary transitions between high- and low-quality forages, 10 rumen-cannulated Hu sheep were randomly allocated to two dietary treatments (five sheep each) with the same concentrate-to-forage ratio and concentration mixture, but different forage sequences: (i) alfalfa hay (AH) to corn stover (CS) and back to AH; and (ii) CS to AH and back to CS. A significant decrease in the rumen microbial protein concentration was observed on day 6 after dietary transition whether the transition was from AH to CS or from CS to AH, and this was accompanied by an increase in the ammonia nitrogen concentration as well as a decrease in the total volatile fatty acids concentration and pH. However, after transitioning back to the original forage, the rumen fermentation parameters returned to their initial levels within 2 weeks. Our findings suggest that abrupt substitutions of forages with large nutrient differences could influence rumen function to some extent, but recovery can occur within 2 weeks without detrimental effects. Furthermore, we speculate that the variation of fermentation in the first 6 days may indicate an important rumen transition stage that requires further study.

中文翻译：

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牧草变化对绵羊瘤胃发酵动态变化的影响。

为了更好地了解高品质草料和低品质草料之间的饮食转换过程中的瘤胃适应性，将10只瘤胃插拔的Hu羊随机分配到两种饮食处理中（每只五只羊），它们的精料比和浓度混合物相同，但不同饲草顺序：（i）苜蓿干草（AH）到玉米秸秆（CS），再回到AH；（ii）CS转换为AH，然后返回CS。无论是从AH过渡到CS还是从CS过渡到AH，在饮食过渡后第6天，瘤胃微生物蛋白浓度均显着降低，这伴随着氨氮浓度的增加和氨氮浓度的降低。总挥发性脂肪酸浓度和pH。但是，过渡到原始草料后，瘤胃发酵参数在2周内恢复到初始水平。我们的研究结果表明，营养成分差异较大的草料的突然替代可能会在一定程度上影响瘤胃功能，但可以在2周内恢复而无有害影响。此外，我们推测前6天发酵的变化可能表明重要的瘤胃过渡阶段需要进一步研究。