Effect of locally produced phytase on growth of layer chicks

The most active and thermo-stable fungus aspergillus niger was isolated and selected as fermenting agent to produce economical microbial phytase on defatted rice polishings through solid-state fermentation (ssf). maximum enzyme activity was obtained at 100 μg /ml after 96 hours of incubation,40% moisture level and 37°c. this enzyme phytase thus produced was biologically evaluated on 180 growing layers of 9 weeks of age. group-a (control group) was without phytase supplementation,however,supplemented with 0.4% non-phytate phosphorus provided by di-calcium phosphate (dcp,1.10%). in groups b,c and d,the phytase levels were kept at 1000,1500 and 2000 μg/kg,respectively. the dcp was added 50% less in all groups as compared to control group. total feed consumption,weight gain,feed conversion ratio of 18 weeks aged pullets in groups a,b,c and d were 2920,2862,2914 and 2931g; 543.15,518.37,549.70 and 568.00g and 5.38,5.52,5.30 and 5.16,respectively. the toe ash percentage was 11.9,11.2,12.1,and 12.7%,respectively and there was significant difference (p<0.05) among different experimental pullet groups. the growth performance was non-significant (p>0.05) among all groups although there was significant availability of phosphorus 42.67,50.00,54.68 and 60.67%,respectively in groups a,b,c and d. there was linear increase (p<.05) in percentage of phosphorus availability with increase in level of phytase. copyright 2010 zoological society of pakistan.