The response of fast-, medium- and slow-growing chickens to a low protein diet

The aim of the present study was to evaluate effect two dietary protein levels on performance, carcass characteristics, and meat quality parameters in fast- (Ross 308), medium- (JA757), slow-growing (ISA Dual) chickens assess interaction factors. Each genotype divided into a control group fed commercial type feed mixture an experimental low-protein diet (LP). trial terminated after common period fattening each genotype, 20 per (sex ratio 1 : 1) were selected for analysis. results indicated that LP decreased growth (P < 0.001) increased consumption more fast-growing than genotypes; however, reduced mortality detected chickens. had negative European performance efficiency factor (-10%) medium-growing (-6%) but not main characteristics included highest dressing out breast percentage thigh abdominal fat genotype. only minor traits. Regarding characterized by higher contents dry matter crude lower ether extract cholesterol compared individual effects genotypes manifested largest cross-sectional area muscle fibres pectoralis major 0.001). indicate significant negligible composition physical chemical