棉粕与豆粕在反刍动物瘤胃内降解动力学的评定分析

Comparative Analysis of Rumen Degradation Kinetics of Soybean Meal and Cottonseed Meal in the Ruminant

本试验旨在评定棉粕与豆粕的干物质(DM)、有机物(OM)、粗蛋白质(CP)在绵羊瘤胃内的降解动力学参数变化及瘤胃降解前后有效赖氨酸的含量变化。选用3只安装有永久性瘤胃瘘管的体重为(28.0±2.97)kg的育肥哈萨克公羊,代谢笼内单笼饲喂,每天饲喂棉籽壳200g、精料500g、小麦秸500g,余料不超过10%。采用尼龙袋技术评定棉粕与豆粕DM、OM及CP的降解动力学参数,计算有效降解率(ED)及瘤胃停留时间(RRT),染料结合法(DBL)测定有效赖氨酸的含量。结果表明,在瘤胃固相食糜的平均外流速度为1.84%/h条件下,豆粕DM、OM及CP的瘤胃降解率及有效降解率均高于棉粕,而瘤胃停留时间均短于棉粕。豆粕经瘤胃内培养16h后有效赖氨酸含量略有升高,而棉粕无明显变化。该试验结果为进一步评定棉粕及豆粕养分的小肠消化率提供参考。

A comparative experiment was conducted to assess the rumen effective degradability of dry matter （DM） ,organic matter （OM） and crude protein （CP） of soybean meal and cottonseed meal in the ruminant and effective lysine content before and after rumen degradation in this study. Three rumen cannulated Kazakh wethers weighed in average （28.0 ± 2.97）kg body weight were housed in metabolic crate singly. The daily diet was composed of cottonseed hull 200 g, concentrate 500 g, wheat straw 500 g,and the daily refusals were less than 10%. The effective degradability of DM,OM,and CP in soybean meal and cot- tonseed meal as well as rumen retention time were evaluated by the standard nylon bag technique. The effective lysine content in both feeds were determined by the dye binding method. The results showed that under the conditions of solid phase in the rumendigesta average outflow velocity of 1.84 %/h, the rumen degradability and effective degradability of DM, OM and CP in soybean meal were higher than that in cottonseed meal, and rumen retention time of soybean meal was shorter than that of cottonseed meal. Effective lysine content of soybean meal after 16 h rumen incubation increased slightly, while no significant changes for cottonseed meal. Results of this study provide some important parameters for further evaluating intestinal digestion of protein and amino acids for future.