Sorghum is used as an alternative to corn due to its lower cost and wide availability. However, conventional sorghum contains high concentration of tannin and phytate, which act as antinutritional factors. Use of microbial phytase may hydrolyze phytate and subsequently improve P absorption. High-lysine sorghum is a new variety of sorghum which may be comparable to other cereal grains and may serve as alternative to corn for pigs. However, there are at this point no data for effects of adding phytase to diets containing sorghum and no data to demonstrate the nutritional value of high-lysine sorghum.
Therefore, 2 experiments were conducted to test the hypothesis that inclusion of 500 phytase units (FTU)/kg of microbial phytase improves the standardized total tract digestibility (STTD) of P in sorghum varieties. The second hypothesis was that the STTD of P, as well as concentrations of digestible energy (DE) and metabolizable energy (ME) in high-lysine sorghum is not different from that of corn and other sources of sorghum.