Soybean Meal Response to Phytase

A study was conducted to determine if different commercial available soybean meals respond similarly to a feed with added phytase. Twenty-five soybean meal samples were obtained from U.S. soybean processors and eighteen lots were selected to evaluate the effect of a microbial phytase on phytic phosphorus disappearance using a five-day chick bioassay. The ranges of component values in the soybean meal samples were reported as follows: total phosphorus (0.59-0.87%); phytate phosphorus (0.32-0.42%); calcium (0.28-0.54%); protein (40.4-51.7%); protein solubility (65.1-86.4); neutral detergent fiber (7.8-16.1%); and urease index (.01-0.25 units pH increase). The five-day bioassay was designed to maximize total phosphorus retention and phytate phosphorus disappearance by feeding a 2.5:1 ratio of calcium to total phosphorus and a 3.85:1 ratio of calcium to phytate phosphorus. Results indicated that supplementing the diet with 1000 FTU/kg phytase increased phytate phosphorus disappearance (62.7%), retention of total phosphorus (30.8%), gross energy (1.44%), nitrogen (3.61%) and calcium (21.78%). Feeding phytase significantly improved (P>0.05) body weight, feed consumption and feed utilization in some groups compared to the control diet. Supplementing the diet with phytase increased the range of phytate disappearance from 13.6-37.1% to 76.2-94.1%. On the average, supplementing the diets with phytase resulted in 82.5±0.96% of the phytate phosphorus being utilized in these experiments. The results indicated no correlation between the source of the soybean meal samples and phytate phosphorus disappearance or total phosphorus retention.

Manangi, M.K. and C.N. Coon. 2006. Evaluation of phytase enzyme with chick fed basal diets containing different soybean meal samples. J. Applied Poultry Research 15: 292-306.