Effect of supplementation of two different sources of phytase on egg production parameters in laying hens and nutrient digestiblity

Hens were fed corn-soybean meal diets containing 0.35,0.25, 0.15, or 0.10% nonphytate phosphorus (NPP) (40 to 60 wk). Phytases A and B were added at 0 .25, 0.15, and 0.10% at 250 to 300 units of phytase (FTU)/kg feed in a 3 x 3 factorial; 0.35% was a control diet. Treatments were replicated with eigh t cages per treatment (five hens per cage) in a randomized complete block d esign. Phytase supplementation had a significant effect on several producti on parameters: feed intake, feed conversion, and egg mass. Results showed n onsignificant effects (P < 0.06) on feed intake when hens were supplemented with phytase A or B and consumed more feed compared to the basal diet at 0 .10% NPP. The feed conversion of birds fed 0.10% NPP without phytase was th e least efficient compared to the other nine treatments (P < 0.05). Egg mas s was significantly greater for hens supplemented with phytases A and B tha n for hens fed the basal diet at low (0.10%) NPP (P < 0.05). There were no significant differences in egg production, egg weight, specific gravity, Ha ugh units, wet shell, or dry yolk percentages. Dry shell percentage was hig her among basal diets at 0.15 and 0.25% NPP in contrast to phytase, whereas albumen and dry yolk percentages were significantly higher for diets with phytase than for the basal diet at 0.10% NPP. Bone ash percentage was uncha racteristically high in liens fed 0.10% NPP without phytase; however, morta lity was 22% in this group. Phytase supplementation improved Ca and P diges tibilities to varying degrees. Supplementation of phytase in normal, corn-s oybean meal diets improved feed intake, feed conversion, and egg mass and e licited a response in shell quality and egg components at the low (0.10%) N PP.