Effects of protease, duration of fattening period and sex of broilers on carcass conformation measures

Abstract

This study analyses the effect of different protein levels in broiler feeds (supplemented with protease), different lengths of fattening period and sex on body conformation in fast-growing Cobb 500 broilers. Complete feeds for broilers in experimental groups E-I and E-II contained 4 and 6% less crude protein than the control (C) and were supplemented with protease (Ronozyme Pro Act) at a concentration of 200mg/kg feed and 300mg/kg feed respectively. At 49 and 63 days of age, 10 male and 10 female broilers were randomly selected from each experimental group and slaughtered. Body conformation measurement included absolute carcass conformation measures (metatarsus length, keel length, breast depth, breast angle, thigh girth) and relative body conformation measures - conformation indices (body weight/metatarsus length, body weight/keel length, body weight/breast depth, body weight/thigh girth). The results showed that dietary treatment did not affect conformation measures, as well as that the time of slaughter and sex of chickens had a significant effect on the examined carcass quality parameters. Namely, the length of the fattening period affected all conformation indices, as well as some absolute measures of carcass conformation - metatarsus length, keel length and thigh girth, while sex had a significant effect on the values of the all absolute values of carcass conformation (except for breast angle) and indices body weight/keel length and body weight/breast depth.