THE EFFECTIVENESS OF PHYTASE IN BROILER DIETS IN IMPROVING PRODUCTION PERFORMANCES AND BONE FEATURES

The possibilities of use of microbial phytase in maize/soybean meal diets for broilers from 21 to 42 days of age with different dietary total and available phosphorus (TP and AP) levels were investigated. A 22-day experiment was carried out on 240 Arbor Acres broilers of both sexes divided into six groups. The broilers were given diets with 0.43%, 0.23% or 0.10% AP, with or without phytase supplementation. During the experiment, health status and mortality, physical, chemical and morphological bone characteristics were investigated. Reduction of the mineral source of P from the diet increased mortality and health problems. Addition of phytase decreased mortality and alleviated negative effects of dicalcium phosphate exclusion. Histological, physical and chemical analysis of broiler tibia indicates that the extent and significance of changes depend on P deficiency and phytase addition. Phytase efficacy was greater in diets with a reduced level of dicalcium phosphate.