EFFECT OF MICROBIAL PHYTASE SUPPLEMENTATI ON ON PERFORMANCE DATA AND METABOLISM OF PHOSPHORUS, CALCIUM AND NITROGEN AT DIFFERENT LEVELS OF CALCIUM SUPPLY IN BROILERS

In a 2factorial fattening experiment with broilers microbial phytase w as added to the diet (corn, wheat and sop extracts) in levels of 0, 20 0, 400, 600, 1000 U/kg at different dietary Ca contents (0.62%, 0.79%) . The P content was 0.59%. Up to levels of 600 U/kg the phytase supple mentation improved the performance data of the animals as well as the retention and utilization of P. Retention and utilization of Ca increa sed up to the highest level of phytase supplementation. Retention of N changed proportionally to live weight while N utilization was not aff ected by phytase treatment. At low Ca levels symptoms of Ca deficiency were observed which declined with increasing phytase supplementation. The highest phytase level resulted in a complete compensation of Ca d eficiency symptoms as compared to the Ca rich diet.