不同放牧强度对滩羊生产性能影响的研究

五种不同放牧强度，历期154d的滩羊放牧试验结果表明：滩羊的采食量随着放牧强度的加重而降低，同一放牧强度下，随着放牧时间的推移，采食量先是逐渐增大，尔后又下降；不同放牧强度下，滩羊的体重随着时间的推移总体上都呈增加的趋势，但放牧强度轻的处理日增重峰值较高，持续时间较长：滩羊个体增重与放牧强度之间存在着强的负相关，单位草地面积(1hm^2)增重与放牧强度之间呈强的正相关：随着放牧强度的加重，饲料报酬先增大后减小，在同一放牧强度下，饲料报酬随着时间的推移先升高后降低；当放牧强度超过0．750只／hm^2以后，滩羊出现了空怀、产羔率降低和推迟怀孕的现象。综合考虑各研究指标，本类草地放牧强度以不超过0．750只／hm^2为宜。

Studies on Effects on Productivity of Tan Sheep Under Different Grazing Intensity

There were five different grazing intensities, it was studied on the grazing of Tan sheep in 154 days. The results showed that: Feed intake of Tan sheep decreased as the grazing intensity became heavier. Under the same grazing intensity, feed intake increased at first, and then decreased as the time passed. The live weight of Tan sheep appeared increasing tendency as the time passed under the different grazing intensity, but the peak figure of ADG under the lighter grazing intensities was higher and lasted longer. There was negative correlation between the live weight gain per sheep and the grazing intensity. There was positive correlation between the live weight gain per hectare and the grazing intensity. Feed conversion increased at first, and then decreased as the grazing intensity became heavier. Under the same grazing intensity, feed conversion increased at first, then decreased as the time passed. After the grazing intensity over 0.750sheep/hm2, the barren rate of tan sheep rose, the lambing percentage dropped and the pregnant time postponed. Considering the different research index, the grazing intensity of this type range ought not to overtake 0.750sheep/hm2.