The overriding objective of this research was to improve the industry-wide lack of knowledge of how wheat particle size and pelleting of complete diets containing wheat for nursery and finishing pigs can improve performance and economic return for swine producers. In order to accomplish this overall objective, two experiments were conducted to evaluate the effects of fine grinding and pelleting wheat on growth performance, nutrient digestibility, carcass characteristics, and economic return of grow-finish pigs. In Exp. 1, hard red or soft white winter wheat was ground to approximately 600, 400, or 200 µ and fed in pelleted wheat-soybean meal diets to grow-finish pigs to measure pig performance and economic costs of particle size reduction and pelleting. In Exp. 2, hard red winter wheat was ground to approximately 800, 600, or 400 µ and fed in meal diets in a similar trial.
Pigs fed hard red winter wheat consumed more feed, grew faster, and had greater DM digestibility than pigs fed soft white winter wheat with no appreciable differences due to grinding finer than 600 µ when fed in pelleted diets. For meal diets, grinding wheat less than 800 microns linearly improved feed efficiency and nutrient digestibility to the smallest micron size fed. Grinding the wheat for meal diets improved the caloric content of the wheat by 100 kcal of NE/lb or approximately 25 kcal NE per 100 microns.
When pelleting, reducing particle size from 600 to 200 µ of both wheat sources increased pellet durability index. Although the impact on cost of production was modest, electrical needs per ton were reduced with fine grinding of soft white winter wheat, but increased with grinding of hard red winter wheat. This difference may be related to the greater pellet durability index achieved with hard red than soft white winter wheat.
Producer bottom line;
• Similar to recent research at Kansas State University with corn, feed efficiency appears to improve as wheat particle size is reduced to less than 600 µ when fed in meal diets, but not when fed in pelleted diets.
• Pigs fed hard red winter wheat had superior daily gain and feed intake compared to pigs fed soft white winter wheat, but feed efficiency was similar between wheat sources.
• It is recommended that wheat be ground to a particle size under 400 µ when feeding hard red winter wheat in meal diets for maximum nutrient digestibility.
Dr. Mike Tokach Jon DeJong
Kansas State University Kansas State University
Department of Animal Sciences & Industry Depart. of Animal Sciences & Industry
222 Weber Hall 217 Weber Hall
Manhattan, KS 66506 Manhattan, KS 66506
[email protected] [email protected]