不同放牧制度对大针茅草原营养成分及其消化率的影响

天然草地牧草营养成分含量受生育期影响,随生长季节变化呈逐渐下降趋势.不同放牧制度一定程度上改变了草群营养成分含量及其消化率.研究表明:放牧利用草群的营养成分含量高于无牧对照,其中轮牧区又高于连牧区;放牧绵羊日粮营养成分含量高于天然草地草群营养成分含量,其中轮牧区日粮营养成分含量又高于连牧区.不同放牧制度大针茅草原混合草群及日粮消化率与牧草粗蛋白含量呈正相关,二者均随生长季节变化而降低,但不同放牧制度之间差异不明显.7月以前连牧区放牧绵羊日粮消化率高于轮牧区,7月以后轮牧区日粮消化率高于连牧区.

Dynamic study of nutrilite and digestibility of the herbage on Stipa grandis steppe under the different grazing system

Nutrient content of the herbage on the rangeland is affected by growing period and decreased with changes of the growing season. The dynamics of nutrient content and digestibility of the mixed grasses and the sheep diet change under the different grazing systems. The study demonstrated that the nutrient content of the herbage on the rangeland was higher under grazing than it under no grazing. The nutrient content under rotate grazing (RG) was better than under continued grazing (CG) . The nutrient content of the sheep diet was higher than that on the natural rangeland (no grazing). The quality of the diet in RG was better than that in CG. The digestibility of the mixed grasses and the sheep diet correlate with the nutrient content positively and decrease with the changing seasons. The difference of digestibility among the different grazing systems was not obvious. The digestibility of the diet in CG was higher than that in RG before July, but opposite after July.