ABSTRACT

In an experiment, the influence of phytase enzyme supplementation in the diet of starter broiler . chickens was evaluated. 180 broiler chicks of Ioda breed were used for the study. The chicks were brooded with a commercial broiler starter mash for one week using standard facilities. Regular heat and light were supplied using electric bulbs throughout the period of the experiment. Brooding temperature was adjusted according to changes in ambient temperature and behavioural changes of the chicks. After a week, they were allotted to five iso-nitrogenous (21.50% CP) and iso-caloric (2977.40 kcal/kg ME) dietary treatments compounded to contain 0g/100kg (T;), 10g/100kg (T2), 15g/100kg (Ts), 20g/100kg (T. 4) and 25g/100kg (Ts) of a commercial phytase enzyme preparation for 21 days in a completely randomized design (CRD). Feed and water were provided to the chicks ad-libitum using feeders and drinkers. Daily feed intake and weekly weight changes were measured. The result showed that the, daily feed intake (g), and daily protein intake (g) were not affected (P>0.05) by enzyme supplementation. Final live weight (g), daily weight gain (g), total weight gain (g) and protein efficiency ratio were significantly (P<0.05) higher in T1 (2.11) than TS (1.80) but similar to T2 (2.05), T3 (2.05) and T4 (1.96). Feed conversion ratio was statistically (P><0.05) different in Ts (2.58) and T; (2.02) but similar (P>0.05) in T1 (2.02), Tz (2028), T3 (2.31) and Ty (2.38). Mortality (%) was lowest in TS (0). Total feed cost per bird (A) and daily feed cost per bird (@¥) were not affected (P>0.05) by - enzyme supplementation while cost per kg of feed (A) and cost per kg weight gain (@¥) were significantly (P<0.05) lower in T, and T2 than Ts but similar (P>0.05) in T;, Tz, T3 and Ty. The result of the study has indicated that phytase enzyme could be supplemented upto 20g per 100 kg in the diet of starter broiler chickens.