Arginine need of heavy broiler males: applying the ideal protein concept.

An experiment was conducted to determine arginine need of male broilers between the ages of 42 to 56 d, in conjunction with dietary protein approaching a previously advocated ideal amino acid pattern. Ross x Ross 308 chicks were reared in floor pens (32 pens with 35 birds each) of an open-sided house on common feeds until 42 d of age. From 42 to 56 d of age, birds were fed a corn-soybean meal diet (17% CP, 3,250 kcal/kg ME, and 0.85% lysine) having basal arginine at 0.80%, and then progressive additions of 0.15% were made until 1.25% was reached to form the dietary treatments. Final body weight together with body weight gain and feed conversion through the 42-to-56-d experimental period were optimized at 0.98% arginine. Weight of the chilled carcass was optimized at 1.00% arginine, whereas depot fat that had been removed from the abdominal cavity continued to decrease to the highest level of supplementation. Additional total arginine to 1.05% was needed to maximize weight recovery of fillets and total breast meat. An arginine requirement for nutritional purposes approximating 1.00% as advocated by NRC (1994) is in general agreement with present results for live production and meat yield; however, carcass incidence of skin scratch infections and parts defects from processing stresses continually responded until the highest level to suggest that additional amounts would be needed for immunological and connective tissue challenges.