Predicting live weight using body measurements in Afar goates in north eastern Ethiopia

Abstract

Regression analysis was performed for developing live weight prediction models for Afar goats using data on live weight and linear body measurements of randomly selected 318 goats of different age and sex categories in Gulina woreda, Zone Four of Afar region. Adjusted R 2 , root mean square error, conceptual predictive criterion and Akaike information criterion were used to choose the best fitted regression model and the developed models were verified using 173 bucks of the same breed. In both sexes of young goats (0PPI, zero or no pairs of permanent incisors), live weight was significantly and strongly correlated (r=0.80-0.90) with chest girth, body length, height at withers and neck circumference. In young female goats (0PPI), the relationship between live weight and body measurements was higher than male kids. In the pooled data, significant and strong correlation (r=0.81-0.94) between live weight and body measurements chest girth and body length was noted. Whereas the association between live weight and body measurements height at withers, rump height and pelvic width were found to be significant and moderate (r=0.60-0.65). Model based on body length separately was able to explain 89% of the variation in live weight in females while in males models based on chest girth separately explained 35% of variation in live weight. In the pooled data model based on chest girth alone explained 67% of the variation in live weight. Models developed for animals at younger age and for female goats in the pooled data scored higher R 2 . Models based on two or more measurements were better in explaining the variation in live weight. In Afar goats, models based on chest girth or a combination of body length and pelvic width were found to be important for predicting body weight irrespective of age and sex.