The effects of various organic acids on phytate phosphorus utilization in chicks

Previous research from our laboratory has shown that citric acid improves phytate P utilization in chicks fed a P-deficient corn-soybean meal diet. The current study was conducted to determine if other organic acids also are effective, with an emphasis on gluconic acid. Four experiments were conducted in which 4 replicate groups of 5 crossbred chicks (New Hampshire x Columbian) were fed a P-deficient diet (0.16% nonphyate P) from 8 to 22 d of age. In Experiment 1, chick weight gain and tibia ash were significantly increased (P < 0.05) by 1.5 and 3% sodium gluconate (NaGlu), 1.5% calcium gluconate (CaGlu), 1.5 and 3% glucono-δ-lactone, and 1% 2-hydroxy-4-methylthio butanoic acid (Alimet). In experiment 2, tibia ash was significantly increased (P < 0.05) by 2% NaGlu, CaGlu, and citric acid in chicks fed the P-deficient diet but not in chicks fed a 0.45% nonphytate P diet, indicating that the organic acid responses were due to increased P utilization. In experiments 3 and 4, tibia ash was significantly increased by 3% NaGlu and 3% citric acid, but not by 3% fumaric acid or 0.025, 0.05 and 0.1% EDTA. The results of this study showed that NaGlu, CaGlu, glucono-δ-lactone, Alimet, and citric acid, but not fumaric acid or EDTA, improved phytate P utilization in chicks fed a corn-soybean meal diet.