Effects of supplemental phytase on nutrient excretion and retention in broilers fed different cereal based diets

Abstract

A 21-day experiment with day-old broilers was conducted in order to assess the effect of phytase supplementation to different cereals-soybean meal based diets on nitrogen, calcium, total and phytate phosphorus excretion and retention. Diets were formulated to contain 4 different cereals (maize, wheat, triticale and barley), 2 levels of dietary calcium (0.6 and 1.0%) and 3 levels of supplemental phytase (0, 500 and 1 000 PU/kg). Nutrient intake, excretion and retention were determined in the first three days of the 2nd and 3rd week of trial. The increasing phytase level resulted in reducing phytate phosphorus excretion and increasing its retention. Significant differences were obtained only in the 2nd week (excretion P < 0.024 and retention P < 0.044). Phytase supplementation significantly influenced total phosphorus excretion in the 3rd week (P < 0.048) and retention in the 2nd week (P < 0.015). The effects of 500 and 1 000 PU/kg were not statistically different from each other. No significant influence of phytase supplementation on nitrogen and calcium excretion and retention was observed.