Sparing effect of phytase enzyme on inclusion of inorganic phosphorus sources (dicalcium phosphate) in broiler diets
P.C. BOLKA, B.S.V.REDDY, R.G.GLORIDOSS, A.S.RAJENDIRAN 1,
T. R. SRINIVASA KUJA AND B. N. SURESH
Department of Animal Nutrition
VeterinaryCollege, University of Agricultural Sciences
Hebbal, Bangalore-560 024
1 SRRC [CSWRI], Kodaikanal - 624 103
A broiler study was conducted to evaluate the sparing effect of phytase-2000 on the inclusion of inorganic phosphorus sources in which three levels of phytase (0, 0.05 and 0.1%) each at two levels of available phosphorus (Pav) (0.1 and 0.2%) and in turn each of such combinations at two levels of calcium (0.8 and 1.0%) formed 12 diets besides a standard BIS specified control. Each of 13 diets was offered to duplicate groups of 10 chicks (equal sex) each and were reared in battery brooders for 42-days. The cumulative mean body weight gain (953.5 to 1566g/bird), feed consumption (2570 to 3545 g/bird) and feed conversion ratio (2.70 to 2.27 g feed/g gain) were significantly different (P<0.05) through out the experiment. Groups with low dietary Pav (0.1%) showed leg weakness, ruffled feathers and ascites. The terminal dressing percentage of birds ranged from 64.06 (0 phytase, 0.1Pav, 1.0 % Ca) to 72.96 (0.05 phytase, 0.2 Pav, 0.8 % Ca). The mean meat: bone ratio and weights of heart, liver and gizzard (as % body weight) were found to be non significant (P>0.05). The bone ash profile revealed that incorporation of phytase in the broiler diets led to higher tibial ash and toe ash contents as a result of the increased utilization of minerals due to hydrolysis of phytate by the phytase (0.10%) with higher calcium (1.0%) and higher Pav (0.20%) when compared to control group. The mean plasma inorganic phosphorus and the serum calcium (mg/dl) were found to be statistically similar (P>0.05) indicating that Ca uptake and its homeostasis in the blood are independent of the levels of phytase, Pav and Ca. The net returns ranged from as low as Rs.-0.026/bird to Rs.11.86/bird. It was concluded that phytase-2000 enzyme supplementation at 0.10 per cent level to diets containing the Pav level of (0.2%) at low level of calcium (0.80%) was found to be beneficial for broilers.