黎平黄牛体重估测公式探讨

Study on the Formula of Estimated Body Weight for Liping Yellow Cattle

随机实测２６１头黎平黄牛的胸围、体斜长和体重，根据体重等于体积乘以密度（比重）的原理，采用回归分析方法进行了黎平黄牛体重估测公式的推导与验证。结果表明，黎平黄牛的性别对体尺与体重回归关系的影响差异不显著（Ｐ＞０．０５），合并公母牛的体尺体重数据，得出该品种总的体重估测公式：体重（ｋｇ）＝胸围２（ｍ）×体斜长（ｍ）×８８－８（ｒ＝０．９９７１，Ｓｙ／ｘ＝４．７０１）。胸围、体斜长对体重的回归关系极显著（Ｐ＜０．０１），估测体重的离回归标准误为４．７０１ｋｇ，平均估重误差为１．７５％。而约翰逊公式用于估测黎平黄牛的体重，相差１６．８ｋｇ～２２．１ｋｇ，平均估重误差为７．７５％，说明应用本回归公式估测黎平黄牛体重可更为准确地反映黎平黄牛的实际体重。

Chest measu rement(CHM),body length(BL)and body weight(BW)of 261 Liping Yellow Cattle were randomly measured on the spot to ascertain and verify the formula of its estimated BW in accordance with the principle of that BW is equal to volume timed by density(specific gravity)using regression analysis method.The findings show that the influence on regression between males and females has no significant difference(P>0.05).Therefore the data of both sexes were merged and a total formula of its estimated BW was made;BW(kg)=CHM 2(m)×BL(m)×88-8(r=0.9971,S y/x =4.701).There is a significant regression between CHW,BL and BW(P<0.01).Its standard error of estimate is 4,701 kg and mean error for estimted BW is only 1.75%.However,the BW of this variety is highly estimated by 16.8kg to 22.1kg with Johnson’s formula and its mean error is 7.75% comparatively.It indicates that estimated BW with the formula mentioned in this paper can more accurately represent the actual BW of Liping Yellow Cattle.