Two experiments were conducted with young pigs and chicks to assess the effect of microbial phytase on protein utilization with growth performance as the response criterion. Chick weight gain, gain/feed, and body protein accretion increased linearly as a function of protein intake, but microbial phytase did not increase the slope of the accretion curves. Pigs fed 24% crude protein from soybean meal had significantly greater weight gains and gain/feed responses than pigs fed 125 crude protein from soybean meal. Again, no significant differences were observed with the addition of 1200 units/kg of microbial phytase regardless of crude protein level fed. These results indicated that feeding 1200 units/kg of a microbial phytase did not affect protein utilization of soybean meal fed to young chickens or pigs as assessed by growth assays.

Peter, C.M., T.M. Parr and D.H. Baker. 2000. Protein-amino acid utilization in soybean meal for young chickens and pigs as affected by microbial phytase. Abstract 152 presented at the Midwestern Section of ASAS and Midwest Branch ADSA 2000 Meeting, Des Moines, IA.