The effect of addition high rape cake and phytase on nutritive value of diets for broiler chickens

Abstract

diet denoted RC LP+ Phy was supplemented with an enzyme preparation containing phytase at a quantity of 875 FYT.kg -1 . Application of 15% of rape cake into starter and 20% into grower diets (RC HP) allowed for similar body weights and feed conversion ratio as the control group, whereas reduction of phosphorus and calcium content in the starter diet (RC LP) significantly decreased body weight at day 21. The addition of phytase to the starter diet with low level of phosphorus and calcium showed the tendency to improve body weight in this period. Application of rape cake into starter and grower diets had poor effects on fat digestibility in all groups, whereas supplementation of grower diets with a low level of phytase phosphorus and calcium improved the digestibility of total phosphorus in comparison to the control and RC HP diets. A tendency to improve the performance results for diets with rape cake (RC HP) in comparison to the control diet in the second period of fattening (grower diets) was observed. Application of rape cake into the diets had a significantly beneficial effect on slaughter yield, fleshiness and fatty acid composition of meat, but not so on the heart muscle, whereas phytase did not have an