Effect of P source and phytase supplementation on apparent digestibility of P in piglets

摘要

The objective of the experiment was to examine the effect of phytase addition on absorption and apparent digestibility of P when a maize-soybean diet was supplemented by different levels of inorganic phosphate. An isotope ("P) metabolic experiment was carried out on crossbred barrows (15-18 kg BW). Dietary treatments were arranged in a 2 X 2 factorial design with two levels of total P (A:0.67 and L:0 59%) having different levels of P bioavailability (A:0.36 and L: 0.28%), and two levels of microbial phytase (0 and 500 FTU/kg of diet). In phase 1 the pigs fed without phytase, in phase 2, with enzyme supplementation. The apparent digestibility of nutrients was unaffected by phytase. Piglets digested 52.3% of the total P in group 1/A and 1/L with phytase supplementation, it was increased by 7% in group 2/A and 23% in group 2/L. Digestibility of P originating from inorganic P supplementation (MCP) decreased by 11 and 4% in groups 2/A and 2/L, respectively. Phytase supplementation enhanced the apparent digestibility of phytate P from 31.6 to 43.9% and from 35.8 to 54.5% in diet 2/A and 2/L, respectively. These results show that faecal excretion of inorganic P increases and absorption of phytate-P improves by the action of phytase. In summary, the amount of inorganic P supplementation can be decreased and it has environmental benefit.