Effect of Phytase Level and Form on Broiler Performance, Tibia Characteristics, and Residual Fecal Phytate Phosphorus in Broilers from 1 to 21 Days of Age

SIMPLE SUMMARY: The demand for poultry products is increasing at the same time as the prices of raw materials and other ingredients used in feed manufacturing, leading to the implementation of strategies to improve nutrient utilization in broiler diets and reduce feeding costs. One strategy used in broiler production is the dietary supplementation of phytase, an enzyme that assists in phytate degradation. Phytate is the primary storage form of phosphorus (P) in seeds and it accounts for two-thirds of the P in vegetable feedstuffs. Dietary phytase supplementation has become a common practice because the activity of endogenous phytase in broilers does not allow for the adequate utilization of phytate-bound P. Consequently, the effects of phytase have been widely studied and the beneficial effects on broiler growth performance and reduced P excretion into the environment have been previously described. In the present study, broilers were fed a diet with a combination of two phytase forms (coated and uncoated) to assess the effects on broiler performance, tibia characteristics, and residual fecal phytate P. The results indicated no distinct advantage of combining phytase forms, but this information may be useful for the direction of future research. ABSTRACT: The present study evaluated the individual and combined effects of coated and uncoated phytase on broiler performance, tibia characteristics, and residual phytate phosphorus (P) in manure. Two repeated studies were conducted using 240-day-old Cobb 500 by-product male broilers per trial. For each trial, birds were assigned to four treatments with four replicate battery cages per treatment (60 birds/trt) and grown for 21 days. Treatments included: (1) negative control (NC), (2) NC + 1000 phytase units (FTU) coated phytase (C), (3) NC + 1000 FTU uncoated phytase (U), and (4) NC + 500 FTU coated + 500 FTU uncoated phytase (CU). Data were analyzed with a one-way ANOVA and means were separated using Tukey’s HSD. In the pooled data for both trials, all treatments with dietary phytase had a higher body weight (BW) and feed consumption (FC) than the NC on day 21 (p < 0.05). Similarly, a six-point reduction was observed for day 1 to 21 feed conversion (FCR) for U and CU (p < 0.05). All treatments with phytase inclusion differed from the NC in every evaluated parameter for bone mineralization (p < 0.05) and had significantly lower fecal phytate P concentrations compared to the NC (p < 0.05). Overall, bird performance was essentially unaffected by phytase form, indicating that combining phytase forms does not appear to offer any advantage to the evaluated parameters from day 1 to 21.