Effect of Phytase Application to Rape Cake Diet on Nutrient Deposition and Bone Quality in Broiler Chickens

The aim of the study was to evaluate the effect of high rape cake content and microbial phytase added to low-phosphorus diet on deposition of nutrients and energy in body of broiler chickens and quality of their bones. At the beginning, seven 1-day-old Ross 308 chickens were weighed, slaughtered, dried, and their bodies were analysed for gross energy and nutrient content. Next, 90 one-day-old chickens were randomly divided into three groups. The group I was fed control diet (RC), which contained 15% (starter) and 20% (grower) of rape cake of Lirajet cultivar with P (7.5 g kg^-1) and Ca (10 g.kg^-1). The group I I was fed diet denoted as RC LP, which contained less P and Ca (5.8 g.kg^-1 and 6.8 g.kg^-1, respectively) than the control diet. The diet for group III, denoted RC LP+ Phy, contained 5.8 g.kg^-1 of P and 6.8 g.kg^-1of Ca, and was supplemented with enzyme preparation containing 0.35g.kg^-1 of phytase. On the 21^st d of life, the chickens were weighed and six birds from each group were slaughtered, dried, and analysed. The rest of the chickens were fed grower mixtures to 49 d of age and then six chickens were slaughtered and the quality of their bones was evaluated. The reduction of P and Ca contents in diets and phytase application did not influence body weight and feed consumption, but significantly improved the deposition of total phosphorus in chicken body at 1-21 d of age. The highest content of total phosphorus was stated in the femur of the chickens fed diet with normal P and Ca contents. The application of phytase to low-phosphorus diet did not influence the quality of bones.