日粮不同氮硫比对肉羊瘤胃营养物质发酵特性及养分降解的影响

Influence of Different Ratios of Nitrogen to Sulfur in Diet on Rumen Nutrient Fermentation and Degradation in Sheep

为研究不同水平的含硫量及氮硫比对肉用绵羊瘤胃发酵及养分降解的影响,本试验选取16只体重相近(40.78±3.65)kg、装有永久瘤胃瘘管的杂交一代羯羊,随机均分为4组,定量饲喂4种不同含硫量和氮硫比(0.15%,N∶S=10.5、0.20%,N∶S=9、0.25%,N∶S=7.5和0.30%,N:S=6)的日粮。结果表明:肉羊日粮中增加硫或降低氮硫比瘤胃pH不受影响,但NH3-N浓度显著下降、瘤胃总挥发性脂肪酸明显增加。肉羊日粮中添加适宜的硫和氮硫比可促进瘤胃纤维和蛋白的降解。肉羊日粮中适宜的含硫量为0.25%、氮硫比为7.5。

The experiment was aimed to study the effects of different sulfurs or ratios of nitrogen and fermentation and nutrient degradation in sheep. Twenty healthy wethers with an average weight （56.78 sulfur on rumen ± 3.65） kg were divided randomly into d groups which were fed with 4 diets supplied either 0.15%, 0.20%, 0.25% and 0.35% of sulfur or ratios of nitrogen and sulfur （10.5：1, 9.0：1, 7.5：1 and 6.0：1）,respectively. Increasing dietary sulfur or decreasing the ratio of nitrogen and sulfur showed no influence on rumen pH, the significant decrease in the concentration of NH3-N and the significant increase in total volatile fatty acids. Supplementation of the optimum sulfur or the ratio of nitrogen and sulfur in sheep diet could improve the tureen degradability of fiber and protein. The optimum sulfur or the ratio of nitrogen and sulfur were recommended to be 0.25% or 7.5 in sheep diet.