Enhancement of phytate phosphorus availability in the diets of commercial broilers and layers

Abstract A reference diet (10.0 g Ca and 4.5 g nonphytate phosphorus, NPP kg −1 ) and two basal diets (basal diet A, 10.0 g Ca and 3.0 g NPP and basal diet B, 7.5 g Ca and 3.0 g NPP kg −1 ) with or without additives were fed to broilers from 3 to 30 days of age. Phytase (500 and 500 phytase units, kg −1 ), cholecalciferol (100 or 200 μg kg −1 ), yeast culture (13.5 × 10 9 Saccharomyces cerevisiae cells kg −1 ) were supplemented to basal diet A and phytase (250 phytase units kg −1 ) or cholecalciferol (100 or 200 μg kg −1 ) were added to basal diet B. Phytase supplementation to basal diet A significantly ( P  ≤ 0.05) improved weight gain compared to unsupplemented basal diet A. Supplementation of either phytase or cholecalciferol to basal diet B resulted in comparable weight gain and feed efficiency as those fed the reference diet. Tibia ash content was not improved when the above supplements were added to basal diets compared to reference diet fed birds. However, supplementation of cholecalciferol at 200 μg kg −1 basal diet A significantly improved the tibia ash content. Highest P retention and serum inorganic P were observed, when both the basal diets were supplemented with phytase. A reference diet (36.0 g Ca and 2.0 g NPP kg −1 ) and two basal diets (basal diet A: 36.0 g Ca and 1.0 g NPP kg −1 and basal diet B: 36.0 g Ca and 1.5 g NPP kg −1 ) were prepared. No inorganic P supplement was present in basal diet A. Both the basal diets were supplemented with phytase (250 PU), cholecalciferol (200 mcg kg −1 ) or yeast culture (13.5 × 10 9 Saccharomyces cerevisiae cells kg −1 ). All the diets were fed to layers for 57 days from 338 to 394 days of age. Feeding of basal diet A resulted in significantly ( P  ≤ 0.05) lower egg production (62.8 eggs per 100 birds per day) compared to those fed the reference diet (90.8 eggs per 100 birds per day), however, phytase supplementation to this diet improved ( P  ≤ 0.05) egg production (91.0 eggs per 100 birds per day), feed per dozen eggs, egg weight, shell quality and final body weight ( P  ≤ 0.05) to the level of birds fed reference diet. Cholecalciferol or yeast culture supplementation failed to improve the layer performance. Feeding of basal diet B with or without supplementation resulted in layer performance that was similar to the reference diet fed layers, suggesting that under this experimental conditions 1.5 g NPP kg −1 diet is sufficient for WL layer. Results of this study indicate that dicalcium phosphate can completely be replaced with phytase (250 phytase units kg −1 diet) in WL layer diet.