摘要
采用6×6拉丁方设计方法,研究了日粮精料水平与秸秆氨化对绵羊瘤胃纤维降解的影响。以氨化与未氨化小麦秸样本瘤胃培养48小时的尼龙袋干物质消失率(ISDMD)作为瘤胃纤维降解程度的度量指标。对瘤胃 PH、VFA 与 NH_3—N浓度等瘤胃参数进行了测定。结果表明,随日粮精料水平的提高,绵羊瘤胃纤维降解程度下降。其中,精料水平由30％提高到50％没有明显下降(P>0.05),而精料水平由50％提高到70％显著下降(P<0.05)。在同一瘤胃环境中培养的氨化麦秸样本 ISDMD 总是明显高于未氨化麦秸样本。在相同精料水平下,饲喂氨化麦秸日粮的绵羊瘤胃纤维降解程度低于饲喂未氨化麦秸粮的动物。对瘤胃纤维降解与瘤胃参数变化的关系进行了讨论。
Effects of dietary concentrate level and ammoniation of straw on the rumen fiber degradation of sheep was investi- gaeted with rumen—cannulated adult sheep in a 6×6 lantin—square designed experiment.The in sacco dry matter disap- pearance(ISDMD)of samples of ammonia—treated wheat straw(AS)and untreated wheat straw(US)incubated in the tureen for 48 hours was used as an indicator of the eaxtent of rumen fiber degradation.Six rumen envirouments were cre- ated by feeding AS and US to sheep at dietary concentrate levels of 30%,50% and 70% on an air dry matter ha- sis.Rumen characteristics including PH value,VFA and NH_3-N concentration were measured.It was shown that the ru- men fiber degradation was depressed as dietary concentrate levels increased.There was a significant depression(P<0.05) with concentrate levels increased from 50% to 70%,but no difference(P>0.05)was found with the levels increased from 30% to 50%.Samples of AS incubated in the rumen of animals given either AS or US diets had higher ISDMD val- ues than those of samples of US when they were incubated in the same rumen enviroument.The fiber degradation in the rumen of sheep fed AS diets was always lower than that in animals given US diets at all concentrate levels.The relationship of changes between the fiber degradation and the tureen characteristics was also discussed in this paper.
关键词
日粮精料水平
秸秆氨化
瘤胃纤维降解
瘤胃参数
Dietary concentrate level
Straw ammoniation
Rumen fiber degradation, Rumen characteristics
