Abstract

A 3×2 factorial experiment was used to investigate the effect of varying dietary crude protein levels; optimum (control, 19.64% CP), low (17.72% CP) and high (21.66% CP) diets, fed ad libitum and on skip-a-day bases on the performance and carcass characteristics of broiler chickens. The diets were iso-energetic. A total of 180 3-week old broiler chicks were used at three replicates per treatment and 10 birds per replicate. The feeding trial lasted for 5 weeks. Weight gain was lowest for chickens on low protein diet compared with those fed the optimum (P>0.05) and high protein diets (P<0.05). Chickens fed ad libitum gained more weight (1.62±0.13 kg/bird) than those fed on skip-a-day basis (0.95±0.07 kg/bird). Chickens fed on skip-a-day basis had higher (P<0.05) feed conversion ratio (2.86±0.27) than those fed ad libitum (2.59±0.27). Water intake of the birds significantly (P<0.05) increased with increasing dietary protein. Abdominal fat deposition was promoted (P<0.01) by the low protein diet but reduced (P>0.05) by skip-a-day feeding method. Other carcass characteristics were not influenced (P>0.05) by dietary protein levels but a higher energy to protein ratio promoted the development of organs. Higher values were recorded for carcass characteristics of birds on ad libitum feeding compared with skip-a-day feeding. This study reiterates the benefit of feeding a balanced (optimum) protein diet, ad libitum to broiler chicken finishers.

Key words: Broiler chickens, feed protein, feeding regime, performance.