A Iinear Regression Model was Used to Predict the Weight of Brown Cattle for Meat at Different Ages
[Objective]Body size and weight are an important index to measure the growth and development of cattle,and are of great significance for feeding management and seed selection.In order to construct the regres-sion prediction model of body size and weight of Xinjiang brown cattle and cows.[Method]In this study,a total of 2045 Xinjiang brown cattle with good health and obvious breed characteristics at different age stages were select-ed.The body measurements and weight indicators of Xinjiang brown cattle of different ages and genders were meas-ured,and the data were analyzed.By comparing the relationship between 13 body measurements and only 4 body size indicators with the highest correlation coefficient and weight,a corresponding regression model between body size and weight was constructed.[Results]By comparing the established models,we found that chest circumfer-ence and abdominal circumference were the main factors affecting body weight.Especially for bulls and cows aged 0～6 months,the linear regression models established by using 13 body size indicators had the highest fitting de-grees of 0.918 and 0.942,respectively.The linear regression equation of bulls aged 0～6 months is:Y=-165.185+0.028X1-0.088X2-0.035X3+0.239X4+1.668X5+0.109X6+1.053X7-0.439X8+1.068X9+1.796X10+1.573X11-0.802X12-0.258X13(R2=0.918),The linear regression equation of 0～6 month-old cows:Y=-182.399+0.97X1-0.359X2+0.579X3-0.097X4-0.683X5+0.025X6-0.364X7+0.502X8+0.329X9+1.374X10+1.786X11-0.083X12+0.097X13(R2=0.942);The linear regression models based on four body size indicators had the highest fitting degrees of 0.882 and 0.933,respectively.The linear regression equation of 0～6 month-old bulls was Y=-162.511+0.555X2+1.218X9+0.986X11-0.127X12(R2=0.882),and the linear regression equation of 0～6 month-old cows was Y=-175.941+0.436X2+0.449X9+2.073X11-0.213X12(R2=0.933).Cattle of different sexes had different growth and development rates at different ages,except for bulls aged 13～18 months,which develop rapidly,change greatly and had obvious dynamics.The fitting effect of regres-sion model between body size and weight was not very good,but it showed good fitting effect in other models of dif-ferent ages and genders.[Conclusion]There was a significant correlation between body size and weight of Xin-jiang brown cattle,and a linear regression formula for predicting body weight based on body size was established.The model of cattle aged 0-6 months,7～12 months and over 30 months showed that the predicted body weight and the measured body weight were not significant through paired sample T-test,which could be used to predict the body weight of cattle.The growth and development testing of Xinjiang brown cattle of different ages and gen-ders,as well as weight prediction,had provided some practical production experience.
Xinjiang brown cattleregression modelrelevanceweight estimation
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