独龙牛生长发育规律的研究*

 通过对3月龄到132月龄87头独龙牛体重及主要体尺指标进行观测，构建了不同体尺性状与体重间的回归关系，分析了不同类型牛的体尺指数。结果显示，独龙牛的早期生长速率最快，随着年龄增加，生长速率下降，到40～60月龄后生长基本停止，达到体成熟，整个生长期体重增长速率比其它指标快，成年公牛体重可达400kg，母牛可达350kg；成年公、母牛体高、十字高、体斜长、胸宽、胸围、髋宽、坐骨宽差异不显著（P>0.05），额大宽、管围差异极显著（P<0.01）；早期独龙牛的体高较大，随着年龄的增加，体长的生长速度超过了体高，成年时体长大于体高；独龙牛具有较为典型的肉用和役用特征。

Research on Growth and Development of Dulong Cattle

The target of this study was to reveal the regularity for the growing of Dulong cattle in order to provide basic data for the future work of breeding and developmentThrough the observation of the body size and weight of 87 Dulong cattle with age between 3 and 132 months，the regression relation was constructed between the body size and body weight，compared the body size index of different type of cattleThe results showed that the the growth rate of Dulong cattle was the fastest in its early growth stageThe growth rate descended with aging，ceased and it reached its body maturity when it was 40 to 60 months oldThe weight increasing rate was faster than the other indexesThe body weights of adult male and female cattle were 400kg and 350kg，respectivelyThe difference between adult male and female cattle was not significant（P>0.05）in withers height，cross height，body length，chest width，chest girth，thurl width，ischium width and so on，while the difference was extremely significant（P<0.01）in forehead width and shank circumferenceThe body height exceeded its body length at its young age when the growth rate of body length was faster than that of withers heightThe body length was finally longer than the withers height when it grew upThe Dulong cattle had the typical characteristic of beef and draft cattle.