Improving Phosphorus Availability

Researchers at Mississippi State University conducted a study to determine the effects of graded levels of microbial phytase added to a practical diet for juvenile channel catfish. The researchers measured weight gains, feed consumption, feed conversion, bone ash, bone phosphorus, and phosphorus levels in fecal materials. The results indicated that the addition of 250 units of microbial phytase per kg to practical diets can effectively improve the bioavailability of phytate phosphorus to channel catfish and may possibly eliminate the use of an inorganic phosphorus supplement in channel catfish diets. The researchers caution that the research needs to be confirmed before the supplemental phosphorus is removed from catfish diets and replaced with phytase additions.

Li, M.L. and E.H. Robinson. 1997. Microbial phytase can replace inorganic phosphorus supplements in channel catfish Ictalurus punctatus diets. J. World Aquaculture Soc. 28(4):402-406