EFFECTS OF FEEDING LOW-PROTEIN GROWER DIETS ON BODY COMPOSITION, NITROGEN EXCRETION AND BLOOD PLASMA PARAMETERS OF BROILER CHICKENS

One day old, 120 mixed sex (Cobb 500) broiler chicks were used to evaluate the effects of protein levels in grower diets (4 – 6 wks) of age on carcass parts, breast chemical composition, nitrogen retention and excretion and some blood parameters. Broiler chicks were fed a common starter diet from (0 – 3 wks) of age and from (4 to 6 wks) of age broiler were attributed to the 4 grower experimental treatments with 3 replicates (10 broilers each). The experimental design consisted in a high CP grower diet (T1; 100%, CP = 19%) and those low CP diets (T2, 95% =18, T3, 90% = 17% and T4, 85% = 16%).The results indicated that:Broiler received diet containing 100% of protein required in growing period (T1) had significantly highest breast muscles and drumstick percentages than those in (T4) 85% CP.Chemical composition of breast meat (OM, ASH and E.E%) showed significant figures when broiler chickens fed different dietary treatments.Broiler chickens fed (T4, 85% CP) grower diet retained significantly nitrogen and lower excretion value than Those T1, T2 and T3.All blood plasma parameters were in the normal range except glucose levels which means that no negative effects on decreasing level of protein requirements during growing period on broilers health.Based on the results obtained it can be concluded that feeding broiler chickens lower crude protein diets during the grower period significantly affected carcass parts, chemical composition of breast meat, nitrogen retention and excretion