Effects of substituting fish meal with poultry by-product meal in broiler diets on blood urea and uric acid concentrations and nitrogen content of litter

Abstract

This study was carried out to investigate the effects of dietary substitution of fish meal (FM) with poultry by-product meal (PBM) at 0%, 25%, 50%, 75% and 100% using 360, 1-day-old Arian broiler chicken. The birds were randomly allocated to 30 pens (at density of 0.08 m2/bird) in an open system partially controlled house. The chicks were raised under a photo regimen of 23:1h light to darkness up to 42 days. The five dietary treatments were offered to six replicates of 12 chicks each. Data on productive performance, serum concentrations of urea and uric acid and pH, moisture and nitrogen content of litter were collected at different ages. The mean weight gain, feed intake and feed conversion ratio were significantly decreased in the birds fed on diets containing more than 50% PBM compared to the control birds during days 1–21 of age (P < 0.01). Replacement of FM at different levels with PBM significantly affected either serum urea or uric acid concentrations (P < 0.05). The serum urea and uric acid concentrations was 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 compared to the other birds (P < 0.10). No differences in litter pH were pointed out for dietary treatments. Treating the litter samples by Alum significantly increased their pH values (P < 0.01). The results suggest that, substitution of FM with PBM at different levels had no considerable impact on nitrogen contents of litter.