Research On The Difference In Body Structure And Weight Estimation Of Donkeys In Western Liaoning

The donkey industry in China has a long history and is one of the most abundant and diversified countries in the world.In recent years,with the popularity of donkey products such as e-jiao,donkey meat and high-grade donkey milk,the donkey industry in China has ushered in a new period of development opportunities.The western area of Liaoning province is one of the main areas of the donkey in China.The body size and weight are the characteristics of the donkey.The body size and weight constitute the body structure of the donkey.Therefore,the correlation between the body size indexes and the influence of body size on the body weight of donkeys in western Liaoning can provide a theoretical basis for the future breeding work of donkeys in western Liaoning.In this study,variance analysis,correlation analysis,principal component analysis and regression analysis were used to analyze the differences in body size structure of donkeys with different body heights and the key body size traits affecting body weight.The results of this study are as follows:1.The body length rate,forehead width rate,chest circumference rate,shoulder length rate,bottom width rate,bottom height rate,bottom width and bottom height ratio of the short(S)group were significantly higher than those of the M and H groups(P<0.05).Therefore,body height is not the optimal standard in the breeding of donkey for meat.2.Through principal component analysis,we obtained two independent principal factors from the 15 body size traits of donkeys in western Liaoning province.The contribution rate of the first principal component was the largest,which basically reflected the appearance and structure characteristics of donkeys in western Liaoning province.3.Chest circumference,body length and body height are important indicators affecting donkey weight in western Liaoning.The optimal regression equation of body weight and chest circumference was Y=3.476x1-270.962.4.The results of the weight estimation formula were close to the results of the loadometer measurement,and the adjustment of Carroll and Huntington's formula(changing the divisors from 11900 to 11700)was applicable to the donkeys in western Liaoning.