摘要
Abstract
The purpose of this paper is to explore the growth and development rules of body weight and body size traits of shorthorn cows,and to provide theoretical bases for optimizing the breeding,feeding management and promotion and utilization of short horn cows,so as to achieve the purpose of improving the breeding of this variety.In this study,113 shorthorn cows were used as the research object.The body weight and body height,cross height,body length and chest circumference were measured at five growth stages:birth,6 months,12 months,18 months,and 24 months.The correlation analysis and linear regres-sion analysis were carried out to construct the regression equations of different growth stages.The results showed that the cumulative growth of body weight,body height,cross height,body length and chest cir cumference of short horn cows increased with the increase of month age,while the absolute growth and rel-ative growth decreased with the increase of month age,indicating that the body weight and body size of short horn cows increased with the increase of month age,but the growth intensity and speed decreased continuously,showing that the early growth speed was faster,the late growth speed was slow,and the growth peak was reached at 6 months of age.The regression relationship between body weight and body size indexes of shorthorn cows at each growth stage reached a very significant level(F＞F0.01).The fitting degree of multiple linear regression equation between body weight and body size index of 6-month-old and 12-month-old shorthorn cattle was higher(0.517＜r＜0.765),and that of 18-month-old and 24-month-old shorthorn cattle was lower(0.269＜r＜0.499).There was a significant positive correlation between body weight and cross height and chest circumference(P＜0.01),and the correlation between body weight and chest circumference was the largest.Therefore,chest circumference can be used as the most important re ference index in the breeding of shorthorn cattle,no matter in any growth stage.The body weight of short-horn cattle at 6,12,18,and 24 months of age could be calculated respectively using the following regression equations:Y6=-209.097+3.092X4,Y12=-414.892+4.596 X4,Y18=-102.939+2.963X4 and Y24=-155.042+3.533 X4(X4 indicate bust circumference).关键词
短角牛母牛/体重/体尺指标/回归分析/相关性分析Key words
shorthorn cow/body weight/main body size indicators/regression analysis/correlation analysis分类
农业科技
