Effect of Zinc Supplementation With or Without Phytase on Performance, Mineral Accumulation in Tissues and Immune Response of Broiler

The present study was undertaken to assess the effect of supplementation of Zn with or without phytase on the performance, accumulation of mineral in tissues and immune response of broiler chickens. Two hundred Vencobb 400 unsexed day-old broilers were randomly divided into 4 groups with 5 replicates each. The starter (1-10 d), grower (11-22 d), finisher (23-35 d) diet was formulated to meet or exceed the recommendations of standard commercial broiler chicken except Zn which was not added in diet. The four experimental treatments resulted from a 2x2 factorial arrangements, where factors include Zn (0, 15 mg/kg form zinc sulphate) and phytase (0, 500 U/kg). BW at day 21 and 35 were significantly (P <= 0.01) higher in zinc supplemented groups, however feed intake and FCR were unaffected. Phytase supplementation did not alter the BW, feed intake and FCR. Deposition of Zn in bone and liver was significantly (P <= 0.05) higher in Zn and phytase supplemented birds. Tibia ash, Zn content of muscle and Cu and Mn content of bone, liver and muscle were unaffected by Zn or phytase addition. Antibody titre against Newcastle Disease virus vaccine was significantly (P<0.01) higher in Zn supplemented group, however was unaltered due to phytase supplementation. Results indicated that Zn supplementation to a maize-soyabean based diet improved BW, mineral deposition in tissue and immune response. However there is no additional benefit from the use of phytase.