Recent Advances in the Use of Phytase Enzyme in Diets for Growing Pigs

The effect of phytase enzyme on the digestibility and availability of phosphorus (P) in soya-bean meal was investigated with grower pigs. In addition, the relative effectiveness of different parameters for assessing P availability in slope-ratio assays were compared. The addition of phytase increased growth rate (741 vs 835 g/d; P c 0.05>, lowered the FCR (2.37 vs 2.16; P c O.Ol), increased protein deposition (108 g vs 123 g/d; P c 0.051, and increased the apparent digestibility of P (0.45 vs 0.69; P c 0.01). There were considerable differences in the estimates of P availability depending on whether bone bending moment, total P retention or digestible P intake was the criterion of response. Phytase supplementation increased the availability of P in soya-bean meal from 0.11 to 0.69, when bone bending moment was the criterion of availability.