Effect of dietary phytase at difference phosphorous, high nitrogen on broiler chicks production

الملخص EN

A study was conducted to examine the effects of adding commercial microbial phytase (Ronozyme) FYT / U/ kg diets on the performance in broilers day- fed adequate phosphorus.

Two experiments were run, using seventy two old unsexed Ross-308 broiler chicks, allotted randomly to four treatments× three replicates, each of six chicks, and fed for 42 days.

Experiments used high (0.45 %) and low (0.30%) P with (23 %) (Crude Protein) CP, all at 3(Mega Calorie) Mcal / kg feed.

Data collected in all experiments covered performance, serum metabolites, slaughter and carcass data, tibia bone physical and chemical measurements, Ca and P balances and economical evaluations.

The performance values ((Weight Gain) WG, F I (Feed Intake), (Feed Conversion Ratio) FCR and energy intake) for the 750 FYT /U / kg diets were higher (P < 0.05) in test groups than the control.

Test groups (the 750 FYT / U/ kg diets) mean values for cholesterol and lipids were higher (P < 0.05) than the control except for serum proteins (7.34 ±0 7) in the low nP low CP % plane.

Slaughter and carcass values for the 750 FYT / U/ kg diets revealed that all parameters in slaughter weight, hot and cold carcasses and dressing percentages based upon them and total edible parts % to be higher (P < 0.05) than the control.

All tibia bone measurements for the 750 FYT / U/ kg diets were higher compared to the control.

Total P and Ca consumptions and total P and Ca retentions % for the 750 FYT / U/ kg diets were higher (P < 0.05) compared to the control except for the high (P < 0.05) nP low CP% planes where P and Ca consumptions were lower (P < 0.05) (2960.16 ±4.41 and 4905.60 ± 27.9).Profitability ratios (1.065 and, 1.076,) of the test groups (750 FYT / U) were always higher than the control group.

Results of the present study suggest that the addition of dietary phytase was found to increase the phytin phosphorous utilization and similarly reduce the phosphorous loss in the excreta.