PREDICTION OF BODY FATNESS FROM BODY MEASUREMENTS IN NEW ZEALAND WHITE RABBITS

Abstract

Possibilities of predicting body fatness from body measurements were examined using 121 New Zealand White rabbits aged 90 days. Body measurements included body weight at marketing age (FBW), heart girth (HG), abdomen circumference (AC) and chest width (CW). The fatness indicating traits (FIT) were weights of total body fat (TBFW), non-carcass fat (NCFW), subcutaneous fat (SCFW) and inter muscular fat (IMFW) and TBFW as percentage of marketing body weight (TBFP). Each of FIT was highly significantly correlated with FBW (0.79 to 0.91), HG (0.76 to 0.86), AC (0.70 to 0.85) and CW (0.73 to 0.81). Several prediction equations based on final body weight and linear body measurements alone (simple regression) and on final body weight and linear measurements simultaneously (stepwise regression) were developed. Prediction of FIT based on final body weight alone was more accurate (R2 = 0.62 to 0.82) than that based on individual linear body measurements with the HG being the most accurate predictor within this group. The inclusion of final body weight and linear body measurements into one equation did not increase the accuracy of prediction (+ 2% to +9%). The results further indicate that final body weight alone is a reasonably accurate predictor for body fatness expressed in gram using the equation: TBFW= -120.39 + 0.102 FBW (R2 = 0.82) or as percentage of final body weight using the equation: TBFP= -2.96 + 0.004 FBW (R2 = 0.67) or expressed in grams of non-carcass fat: NCFW= -63.89 + 0.053 FBW (R2 = 0.82) or subcutaneous fat: SCFW= -22.73 + 0.019 FBW (R2 = 0.62) or inter muscular fat: IMFW= -33.66 + 0.029 FBW (R2 = 0.76).