Impact of phytase on improving the utilisation of pelleted broiler diets containing olive by-products

Abstract

A feeding trial was run to assess the effect of olive cake (OC) in pelleted diets at 0, 10 and 15% with or without 500 FTU/kg diet of a bacterial E. coli phytase (BECP) for broiler chickens during early growth phase period (7–28 days of age). The experimental set up including six treatments as 3 OC levels × 2 supplementations (no enzyme and 500 FTU of BECP). Each treatment was replicated eight times, having five male chickens each. Phytase supplementation significantly increased growth rate and improved production index regardless of the level of OC. Inclusion of OC in broiler diets at 10 and 15% did not significantly affect growth rate, European production index and economic efficiency irrespective of BECP supplementation. In addition, phytase supplementation significantly increased growth rate, European production index and economic efficiency, irrespective of OC level. Plasma cholesterol and triglycerides were decreased considerably due to phytase supplementation to 10 and 15% OC diets. In addition, phytase supplementation significantly increased plasma inorganic phosphorus of broiler fed different levels of OC, and economic efficiency of broilers fed 10% OC, and decreased plasma triglycerides and cholesterol of 10 and 15% OC diets. In conclusion, broiler chickens during early growth stage can be fed pelleted diet contained up to 15% OC with or with BECP supplementation, without adverse effects on growth performance, carcase characteristics, plasma lipid profiles, while phytase supplementation to 10% OC diets yield the highest return over cost and economic efficiency. Highlights This investigation highlights the use of phytase to improve oil cake utilisation in pelleted broiler diets; the essential findings are: • Inclusion of olive cake in broiler diets at 10 and 15% did not significantly affect growth rate, European production index and economic efficiency irrespective of phytase supplementation. • Phytase supplementation significantly improved, growth, European production index, and economic efficiency, regardless of OC level. • Phytase supplementation also markedly increased plasma inorganic phosphorus of broiler fed different levels of OC, and economic efficiency of broilers fed 10% OC, regardless of olive cake level. • Plasma cholesterol and triglycerides were significantly decreased due to phytase supplementation to 10 and 15% olive cake diets. • Phytase supplementation to 10% olive cake diets yields the highest return over cost and economic efficiency