秦川牛肉用新品系生长发育规律研究

试验旨在研究秦川牛肉用新品系生长发育特点与规律,为秦川牛肉用新品系后续选育改良提供科学依据。选取不同发育阶段(6月龄、12月龄、18月龄、24月龄和36月龄)的秦川牛肉用新品系各10头,公母各半,共50头,测量其在不同月龄的体重和体尺(包括体高、腰高、体斜长、胸围、胸深、管围、腰角宽、尻长、坐骨端宽),测量3次取平均值,计算体尺指数(体长指数、胸围指数、体躯指数、管围指数),分析体尺与体重之间的相关系数。结果发现:①无论是对于公牛还是母牛,它们在6～12月龄这个生长阶段体重和体尺的生长速度都达到最大,体长指数、胸围指数和体躯指数都是随着年龄的增长而增加。②它们的生长发育符合一般牛的生长发育特点,即最先发育的是体高,其次是体长,最后是胸围。③分析秦川牛肉用新品系体重和体尺随月龄变化的变异系数发现,在24～36月龄时生长发育趋于平缓,初步判定新品系在36月龄时就趋于体成熟。④在对体重与体尺的相关性分析中,公牛和母牛有所不同,公牛各体尺与体重的相关性结果是:体高(0.908)、腰高(0.857)、体斜长(0.856)、胸围(0.994)、胸深(0.913)、管围(0.823)、腰角宽(0.931)、尻长(0.842)、坐骨端宽(0.776);母牛各体尺与体重的相关性结果是:体高(0.909)、腰高(0.826)、体斜长(0.952)、胸围(0.985)、胸深(0.904)、管围(0.738)、腰角宽(0.943)、尻长(0.805)、坐骨端宽(0.876);公、母牛均是胸围与体重的相关性最强,且母牛各体尺与体重的相关性普遍高于公牛。综上所述,秦川牛肉用新品系在生长早期生长发育潜力大,应加强此阶段的饲养管理,使其尽快达到体成熟,同时也应注重性别的差异,公母牛要分群饲养管理,以便获得最大养殖效益。

Study on Growth Rules of New Breed of Qinchuan Cattle

To investigate the growth features and rules of the new breed of Qinchuan beef cattle(hereinafter referred to as Qinchuan cattle), and to provide basic data for further breeding and improvement of Qinchuan cattle, 50 Qinchuan cattle at different ages (6-month, 12-month, 18-month, 24-month and 36-month) were selected with 10 cattle per age(including 5 bulls and 5 cows), their weight and body length (withers height, hip height, body oblique length, chest circumference, chest depth, tube circumference, hipwidth, rump length, ischiumwidth) at different ages were measured for three times to obtain the average value, and to calculate the body size index (the index of body length, chest circumference, trunk and cannon circumference), and the correlation index between their body size and weight was analyzed.The results showed that:①For both bulls and cows at 6-12 month, the growth speed of their weight and size reached the maximum. and the index of body length, chest circumference and trunk were gradually increased with age.②Their growth conformed to the growth features of general cattle, that was, the withers height grew first followed by the body length, and then the chest circumference.③ The variable coefficient of withers weight and body size that changed with ages was analyzed, it was found that the growth of Qinchuan cattle tended to be even at 24-36 month, indicating that the cattle grew maturity at 36 months.④ For bulls and cows, the correlations between body weight and body size was different, and the correlations of bulls were listed as follows: withers height(0.908), hip height(0.857), body oblique length(0.856), chest circumference(0.994), chest depth(0.913), tube circumference(0.823), hip width(0.931), rump length(0.842), ischium width(0.776);and for cows: withers weight(0.909), hip height(0.826), body oblique length(0.952), chest circumference(0.985), chest depth(0.904), tube circumference(0.738), hip width(0.943), rump length(0.805), ischiumwidth(0.876). The correlation between chest circumference and body weight was the strongest both in bulls and cows. Moreover, the correlation between body size and body weight in cows was generally higher than that in bulls. It was concluded that the potential of Qinchuan cattle in the early growth stage was lager, and the breeding at this stage should be improved to make the cattle grow mature, meantime, the difference of sex should also be focused, and the bulls and cows should be bred separately to gain best benefit.