Effect of substituting fish meal with poultry by-products meal in broiler diet on nitrogen excretion and litter characteristics

This study was carried out to investigate the effects of dietary replacment of fish meal (FM) with poultry by-product meal (PBM) at 0, 25, 50, 75 and 100% using 360 one day-old Arian broiler chicken. The mean weight gain, feed intake and feed conversion ratio were significantly decreased in the birds fed on diets containing greater levels of PBM as compared to the control birds during 1 to 21 days of age (P<0.01). Replacement of FM at different levels with PBM significantly affected serum concentrations of urea and uric acid (P<0.05). The serum concentrations of urea and uric acid were lower in the birds that received 100%-PBM containing diets. The mean nitrogen content of litter was similar among the experimental diets, while the moisture content of litter tended to be lower for the birds fed on diets containing 25% PBM as compared to the other birds (P<0.10). Litter pH was similar among the dietary. Treating the litter samples by alum significantly decreased their pH values (P<0.01). The results suggest that, substitution of FM with PBM at different levels had no impact on nitrogen contents of litter.   Key words: Nitrogen excretion, broiler chicken, poultry by-product meal.