P UTILIZATION FROM RAPE SEED MEAL AND RAPE EXPELLER BY LAYING HENS AND BROILERS AND ITS IMPROVEMENT BY PHYTASE SUPPLEMENTATION

Semi-purified diets containing either rapeseed meal (RSM) or rape expe ller (RE) as the sole source of dietary P were fed to laying hens and broilers in order to examine the P utilization of RSM and RE in both b ird types, respectively. In addition, all diet types were supplemented with 3 phytase levels (310, 580 and 1240 FTU/kg RE-containing laying hen diets; 350, 660 and 1250 FTU/kg RSM-containing laying hen diets; 6 0, 370 and 790 FTU/kg RE-containing broiler diets and 210, 420 and 850 FTU/kg RSM-containing broiler diets, respectively) to evaluate the ef fectiveness of phytase supplementation in improvement of P utilization in both rape products. P utilization of unsupplemented RSM and RE was found to be 5.9 and 19.1 %, respectively, for laying hens, 50.2 and 3 1.1 %, respectively, for broilers in age period from day 12 to 16 of a ge and 41.4 and 35.2 %, respectively, for age period from day 26 to 30 of age. The differences in P utilization between both bird types are partly affected by different relationships between total P supply and P requirement. The effectiveness of phytase supplementation was estima ted from linear regression of dietary phytase activity on P utilizatio n. The improvement in P utilization per 100 FTU/kg varied between 1.3 and 2.6 % depending on rape product and bird type. However, the effect iveness of phytase supplementation was statistically not different bet ween all treatments.