Analysis of differences in calf growth under grazing based on energy metabolism as affected by climatic condition

放牧条件下犊牛的生长速度常因不同地区草地植被的季节条件和物种组成而异。从从太阳能输入到有效牧草生长、从牧草供应到牧草采食量、从可消化能到犊牛生长四个阶段分析了犊牛生长速度的差异，转换效率因季节和牧草种类而异。犊牛生长速度与代谢能转化为增重的效率有关，且与植物种类有关。

Growth rate of calf under grazing is often observed to vary with seasonal condition and species composition of pasture vegetation located in different places. The difference in growth rate of calves was anslysed in terms of energy conversion on four steps from solar energy input to available herbage growth, from herbage allowance to herbage intake, from digestible energy to calf growth.The efficiency of conversion varied with season and with species of grasses. Calf growth rate was related to the efficiency from metabolisable energy to gain and the efficiency was related with plant species.