PREDICTION OF TOTAL MILK YIELD OF FRIESIAN X BUNAJI HEIFERS IN EARLY LACTATION USING BODY MEASUREMENTS

This study was conducted to determine whether there is a stable relationship between milk yield and body measurements, and if so how accurate could total milk yield (TMY) be predicted in early lactation of Friesian x Bunaji heifers. The data used for the study was collected from 38 primiparous Friesian x Bunaji heifers at the dairy herd of National Animal Production Research Institute (NAPRI) Shika -Zaria Nigeria. Eight body measurements and eight body indices were used to develop the prediction models. Base on the evaluation criteria, the best model that could optimally predicts TMY in early lactation using the original body measurements was the model that combined body weight (BW), body length (BL) and heart girth (HG); TMY= 3484.60-5.20BW+120.44BL-85.21HG. The model explained about 94.49% of the variation in the TMY of the heifers in early lactation with a low prediction error (RMSEP) and AIC values of 70.67 and 52.50, respectively and the P-value of the resultant model was 0.032. The best model for the prediction of TMY in early lactation using the body indices was the model that combined weight index (WI) and body index (BI) in the form TMY= - 11594.00-0.04WI + 213.034BI. This model could explain over 99% (R2-adj =99.43) of the variation in TMY with low prediction error (RMSEP) and AIC values of 29.36 and 42.39, respectively and the P-value of 0.0004.Therefore, findings of this study suggest that body conformation should be included in the evaluation of replacement heifers in dairy production programme.