Phytase Studies-Rainbow Trout
Three experiments were conducted to evaluate the effects of microbial phytase (Ronozyme P(L)) on the apparent digestibility of dry matter, crude protein, amino acids and minerals in soybean-based diets for rainbow trout. In experiments 1 and 2, the fish were fed soy protein concentrate and soybean meal-based semi-purified diets, respectively. In experiment 3, a soybean meal-based practical was fed. In experiments 1 and 2, phytase supplementation significantly increases the apparent digestibility coefficients of minerals (except copper and iron), but not dry matter. In experiment 3, phytase supplementation significantly increased the apparent digestibility coefficients of dry matter, crude protein, amino acids (except tryptophan and tyrosine) and minerals (except copper and iron). The optimum level of phytase in rainbow trout diets was approximately 500FTU/kg diet.

Cheng, Z.J.J., and co-workers. 2005. Effects of microbial phytase supplementation and dosage on apparent digestibility coefficients of nutrients and dry matter in soybean product-based rainbow trout Oncorhynchus mykiss. J. World Aquaculture Soc. 35(1): 1-15.