Response of Broiler Chicken to Microbial Phytase: Effects on Phytin-Phosphorus, Serum Biochemistry and Carcass Characteristics

Aim: The experiment was conducted to determine phytin-phosphorus in feed, pre-caeca digesta and faecal droppings of broiler chickens and to investigate serum metabolites and carcass characteristics of broiler chicken as affected by phytase supplementation.

Study Design: The experiment employed a completely randomized design. All data generated were subjected to analysis of variance, P= 0.05.

Place and Duration of Study: The study was carried out at the Teaching and Research farm of the Ekiti State University, Ado-Ekiti, Nigeria between February and April, 2011.

Methodology: Two hundred and forty unsexed day-old Anak 2000 strain broiler chicken were used in a 56-day feeding trial. The birds were allotted to five treatments with 4 replicaites per treatment of 12 birds per replicate. Diet 1 was the reference diet with no phytase supplementation but with both plant and animal protein sources. Diets 2 and 3 were duplicate diets with enzyme supplementation only in diet 3. Diets 4 and 5 were also duplicate diets with enzyme supplementation only in diet 5. Diets 2 and 3 had groundnut cake as the major plant protein ingredient while diets 4 and 5 had soybean cake as the major protein ingredient. They were fed ad-libitum. Phytin-phosphorus in feed, pre-caeca digesta and faecal droppings of broiler chickens were determined and the effect of phytase supplementation on serum metabolites and carcass analysis of broiler chicken were also investigated.

Result: The levels of phytin-phosphorus in feed exceeded that detected in pre-caeca digesta of ileo-caeco-colonic junction likewise the levels of phytin-phosphorus in pre-caeca digesta exceeded that detection in faecal droppings. All diets supplemented with or without phytase had no significant influence on all the serum metabolites of broiler finisher investigated in this experiment (P>0.05) but a slight increase in the values of urea, creatinine, cholesterol, triglyceride and high density lipoprotein in the serum of birds with phytase supplementation. There were no significant (P>0.05) differences recorded for the liveweight, dressed weight, eviscerated weight and all carcass cuts percentage of broiler finisher.

Conclusion: The supplementation of broiler diets with or without phytase constituted no danger to the health status of broiler birds. In carcass analysis phytase supplementation promoted muscle accretion.