the effect of different amounts of dietary protein on growth performance and carcass components of cobb strain broilers

the effect of feeding different protein profiles on growth performance, carcass components and nitrogen content of litter in cobb 500 broiler strain was evaluated using 800 chicks in a completely randomized design with four treatments, five replicates groups of 40 birds per each treatment. the treatments were consisted of four protein feeding profiles (based on cobb strain nutrition guide, recommendation by nrc, 90% protein recommended by nrc and phase feeding). the effect of different treatments on body weight gain, feed intake, energy consumption, protein efficiency ratio and carcass components were not significant. the birds were fed based on cobb strain guide had a better feed conversion ratio (p< 0.05). energy efficiency ratio in broilers fed base on protein profile of cobb strain guide was higher than other treatments (p< 0.05). the amount of litter nitrogen in broilers fed with base on cobb strain guide, 90% protein recommended by nrc and phase feeding were lower than those fed base on protein profile of nrc recommendation (p< 0.05). based on the results of this experiment, the use of protein profile base on cobb strain is more suitable for feeding cobb broiler chickens than other profiles.