Application and efficiency of body volume formula for predicting live weight in two strains of broiler chickens in Zaria, Nigeria
Keywords:Arbor Acre, Body length, Body volume, Chest girth, Regression, White Rose
Records from 120 day-old Arbor Acre (n = 60) and White Rose (n = 60) broiler strains of mixed sexes were used. The experiment was carried out at the Poultry Unit, Teaching and Research Farm of the Department of Animal Science, Faculty of Agriculture, Ahmadu Bello University Zaria, Kaduna state. Traits considered from day old to 8 weeks included body weight (BW), body length (BL) as well as chest girt (CG). The chickens were assigned to two treatments with three replications each having twenty chickens per replicate and were fed the same type of feed. The weights were taken on weekly basis. The feed consumed was also measured on daily basis. The body parameter such as body length and chest girth was also taken on weekly basis. The chick's body volume (BV) was estimated by cylinder volume using a formula derived from the work of Paputungan. Results obtained showed that age significantly (P<0.05) affected BW at all ages where the White Rose strain consistently weigh heavier than Arbor Acre. Similarly the BV of Arbor Acre is less than that of White Rose strain only at week 2. No significant difference (P>0.05) was obtained for the other parameters investigated across age. Coefficient of correlation among parameters obtained in this study were low and insignificant (P>0.05). However, all the values recorded were positive indicating that selection for any trait will lead to correlated response in the others. The multiple regression models for predicting live weight from chest girth, body length and body volume in the two strains revealed that coefficient of determination (R2 ) for BV was higher (0.96 to 0.98) compared with those of chest girth (0.56 to 0.73) and body length (0.81 to 0.88). It was concluded therefore that body volume was more efficient and better predictor of live body weight than BL and/or CG.