Date Full Report Received


Date Abstract Report Received



Primary Investigator:
This project specifically evaluated the impact of ultra-high doses of phytase on pork production parameters. Past research efforts have demonstrated positive effects of phytase supplementation at approximately 1,500 to 3,000 FTU/kg, but higher inclusion levels have not been adequately tested in a commercial production environment. The cost of phytase has decreased substantially; therefore, inclusion of ultra-high levels of phytase (beyond those required for P release) becomes economically feasible. In the present study with 2,150 pigs, we demonstrated that mega-dosing of phytase (3,000, 4,500, or 6,000 FTU/kg) linearly improved daily gain and feed efficiency and that this improvement was most dramatic during the final finishing phase (95 to 125 kg of body weight), improving feed efficiency from 3.76 to 3.41 (9.3% improvement). The final finishing phase represents a period of increased stress related to decreasing floor space per unit of pig body weight, resulting in a relatively profound reduction in pig performance. These data suggest that a targeted application of mega-doses of phytase during the final phase of production may be economically attractive compared to supplementation of phytase for the entire growth period.

Key Findings:
• Supplementation of fat improved daily body weight gain and feed efficiency, with the largest effect being observed during the last feeding phase before the first marketing cut.
• Supplementation of phytase at up to 6,000 FTU/kg improved daily gain and feed efficiency, especially during the final feeding phase before marketing.
• Supplementation of phytase (3,000 FTU/kg) to diets with added fat (4% choice white grease) did not impact performance of pigs.
• Supplemental phytase reduced the number of viable pigs (representing mortalities, light, and cull pigs), which was not observed in previous studies. This potential impact of phytase needs to be further evaluated.
• Collectively, data indicate that mega-doses of phytase during the final phase of production may be economically attractive compared to feeding phytase for the entire growth period.

Contact: Eric van Heugten
North Carolina State University
Raleigh, NC 27695-7621
Phone: (919) 513 1116
E-mail: Eric_vanHeugten@ncsu.edu