西门塔尔牛、南德温牛杂交改良秦川牛效果研究

目的]为研究西门塔尔牛、南德温牛对秦川牛的杂交改良效果.方法]对秦川牛、南德温牛与秦川牛杂交一代（南秦F1）、西门塔尔牛与秦川牛杂交一代（西秦F1）共282头母牛的体高、十字部高、体斜长、胸围、腹围、管围等6项体尺指标进行了测定.以体尺指标为基础材料,对比分析了它们的体重与体尺数据在不同月龄的表现特点;计算分析了它们的各项体尺指数;构建了1～2岁秦川牛各项体尺指标对体重的主成分回归模型.结果]表明：西秦F1比南秦F1的杂交改良效果好,6～24月龄的秦川牛、南秦F1、西秦F1随着月龄的增加,胸围和体重快速增长,西秦F1的各项体尺指标总体上高于南秦F1与秦川牛,秦川牛与南秦F1差异不显著（P＞0.05）;从育肥指数上来看,24月龄的西秦F1比秦川牛平均高7.2％,差异显著（P＜0.05）,西秦F1比南秦F1高6.8％,差异显著（P＜0.05）,南秦F1与秦川牛差异不显著（P＞0.05）,西秦F1育肥效果优于南秦F1.结论]对1～2岁秦川牛通过逐步回归得到了估测体重的多元线性回归方程,拟合度较好.

Improving Effects of Hybrids on Simmental and Qinchuan Cattle,South Devon Cattle and Qinchuan Cattle

Objective]To study the improving effects of hybrids of Simmental, South Devon cattle on Qinchuan cattle. Method]Several body sizes, such as body height, body length, heart girth, and body weight were recorded from 282 Qinchuan cows. Qinchuan cows （NQF1） and the first generation The first generation of South Devon cattle hybridizing of Simmental hybridizing Qinchuan cows （XQF1） were carried out in Lingtai Prefacture of Gansu province, respectively. Based on these data, their body weight and body size data were comparatively analyzed at the level of the performance characteristics in different age, as well as their body size indexes were also alculated and analyzed. Moreover, established to predict the body weight of Qinchuan cattle at 1-2 years old. Results regres ]The sion model was results showed ifican Qin demonstrated no significant difference （P〉0.05）. From the fattening index, at 24 months of age, XQ is 7.2% higher on average body height than that of Qinchuan cattle, and statistical difference was cant （P〈0.05）. However, no significant difference （P〉0.05） between Qinchuan cattle and NQ tly F1 F1 signifi- F1 was found. The XQF1 cattle showed 6. 8% higher than the NQFlcattle （P〈0.05）. Totally, the point of whole fattening effect of XQF1 cattle is better than NQF1 cattle. Conclusion] Through the method of stepwise regression for 1-2 years old Qinchuan cattle, the regression equations of multiple linear were ob- tained and the fitness is better.