Dr. JAYANAIKVIDYASAGAR2021-01-252021-01-252017-09https://krishikosh.egranth.ac.in/handle/1/5810160579The effects of phytase supplementation on growth performance, mineral retention, bone and blood Minerals content, carcass characteristics and economy in Giriraja birds were studied from 1 to 42 d of age. Four hundred twenty one-day-old Giriraja chicks were assigned at random to seven dietary treatments. The basal diet Control (0.45% available P -T1), Low P diet (0.35% available P -T2), low P diet (0.3% available P -T3), Low P diet (0.35% available P + Phytase 500 FTU/kg -T4), Low P diet (0.3% available P + phytase 500 FTU/ kg-T5), Low P diet (0.35% available P + Phytase 1000 FTU/kg -T6), Low P diet (0.3% available P + Phytase 1000 FTU/kg -T7) were fed to respective experimental group of birds. The supplementation of phytase in Giriraja birds diets improved the body weight gain, feed intake and feed conversion ratio at the end of 42nd d of age. Phytase enzyme was effective in significantly improving mineral retention (Calcium and Phosporus). It was also revealed significant (P≤0.05) effect in bone mineral retention (Ca and P) The blood Calcium was not affected significantly by feeding of phytase enzyme but had significant effect on blood phosphorus. The phytase based diets did not show any significant difference in abdominal fat per cent, liver and gizzard weights. However, there was significant comparable effect on dressing percentage and heart percentage. There was significant (P≤0.05) difference in economy in control when compared to experimental groups.EnglishThesis