Influence of dietary protein and energy concentrations on naked neck and normal broilers

Heterozygous naked neck (Nana) and their normal feathered full sib (nana) broiler chicks were fed ad lib diets containing 2600 or 2750 kcal ME/kg in starter (STR) with corresponding 2750 or 2900 kcal ME/kg in finisher (FSR) phases and 19, 21 or 23% protein in STR with corresponding 16, 18 or 20% protein in FSR, in a 2x2x3 factorial manner from day old till 49 d of age. 144, day-old chicks of either genotype, raised in wire floor battery brooders, were used in the study. Both the genotypes showed similar body weight, DM retention, ready to cook yield and abdominal fat content. Feed intake was higher and feed conversion efficiency, weight of feathers and skin were lower in the Nana chicks than in their nana counterparts. No diet x genotype interaction was seen on performance parameters indicating that the Nana and nana broiler chicks did not differ for their protein and energy requirements. Significantly (P<0.01) higher body weight and feed conversion efficiency were seen in both the genotypes with high energy and high protein regimes.