【摘要】 在河北坝上鱼儿山牧场研究放牧强度对杂种公羔采食氮量、排泄氮量、沉积氮量及增重的影响。结果表明 ,随着放牧强度的增加 ,羊干物质采食量逐渐减少 ,同时采食氮量也相应减少 ,但差异不显著 (P>0 .0 5)。放牧强度对羊体沉积氮占食入氮比例的顺序为中牧 >轻牧 >重牧 ,消化氮的利用率也以中牧区最高。在轻牧与中牧区羊的日增重较快更多还原

【Abstract】 The intake N ,deposition N,dung N, urine N and daily gain of lamb under three grazing intensities (LG 0.134hm 2/lamb, MG 0.08hm 2/lamb and HG 0.067hm 2/lamb, with the increase of live weight, the grazing intensities were changed for LG:0.2hm 2/sheep, MG:0.114hm 2/sheep, HG: 0.072 hm 2/sheep) were carried out on a pasture established using Russian Wildryegrass (Psathyrostachys juncea (Fishch) Nevski) during growing season (from June September ) in 1997 at Yuershan Ranch in the north of Hebei province. The results show with the increase of grazing intensity, the intake N of lamb decreased (P>0.05), and the ratios of deposition of N to intake of N were ranked as MG>LG>HG,and the utilizable rate of digested N at medium grazing site was the highest. The daily gain of sheep in LG and MG was higher than in HG.更多还原