Abstract: The research was studied the effect of grazing intensity and grassland type on the lamb performance in agro pastural interlocked region in North China.The results indicated that the effect of the grazing intensity on lamb performance was related with grazing season.The effect of the grazing on the lamb liveweight gain was significant at the early grazing period and late graing period(P<0.01,P<0.05).The grazing intensity had no significant effect on the lamb liveweight at the end of grazing(P<0.05),however the production of the grassland per unit was different under the different grazing intensity(P<0.01).The lamb liveweight production per unit was 533.9kg/hm² (High stocking rate),446.25kg/hm²(medium stocking rate)and 262.91kg/hm²(light stocking rate) respectively.Grassland type had significant difference on the lamb daily gain(P<0.05).The alfalfa Russian wildrye crested wheatgrass was better than the other two kinds,but the others also could apply the nutrient of the lamb growth and liveweight gain.The grazing intensity and grassland kind both had effect on the lamb performance(P<0.01),which showed the different grassland kind,adapted with different stocking rate.The daily dry matter intake and crude protein intake decreased with stocking rate increasing.

Key words: Grazing intensity, Grassland type, Lamb daily gain, Lamb liveweight

摘要： 在华北农牧交错带坝上地区,研究放牧强度和草地类型对肥育羔羊生产性能的影响。结果表明,在育肥期间,放牧强度对育肥羔羊个体增重的影响主要与季节有关。试验结束时,供试羔羊体重间差异不显著(P>0.05),但是单位面积家畜生产性能之间差异极显著(P<0.01),其中以重牧区畜产品产量最高,达192.53kg/hm²×108d,中牧和轻牧区分别为181.6和110.9kg/hm²×108d。杂花苜蓿—扁穗冰草—新麦草草地对羔羊育肥增重效果最为显著(P<0.05)。放牧强度和草地类型互作对羔羊的增重差异极显著(P<0.01)。不同草地类型适宜的放牧强度各异。羔羊干物质和蛋白质日采食量均随着放牧强度的增加而降低。

关键词: 放牧强度, 草地类型, 羔羊日增重, 羔羊活重