#12-146

Complete

Date Full Report Received

07/13/2014

Date Abstract Report Received

07/13/2014

Investigation

Institution:
Primary Investigator:

Industry Summary: Pelleting swine diets is a technology that is widely used in southeastern U.S. feed mills and gaining popularity in the Midwest. Yet, limited research has explored methods to improve pellet quality and subsequent pig performance. Therefore, two experiments were conducted to evaluate the effect of regrinding major feed ingredients on pellet quality and pig performance. For experiment 1, the objective was to determine if adding dried distillers grains with solubles (DDGS) to swine finishing diets or regrinding soybean meal or DDGS improves pellet quality. Diets consisted of two levels of DDGS (0% & 30%), two particle sizes of DDGS (680 & 480 microns) and two particle sizes of soybean meal (1070 & 470). A representative sample from each batch was reserved for determination of pellet quality, as measured by pellet durability index (PDI) and modified PDI. Pellet quality was assessed on the day of manufacture via a tumbling box according to ASAE standard S269.4 (ASAE, 1997). Modified PDI was determined by the addition of three 0.75 in. hexagonal nuts to each chamber of the tumbler box to simulate movement of feed from the feed mill to the barn. For experiment 2, the objective was to determine if regrinding DDGS or reducing pellet fines improves finishing pig performance. The experimental design consisted of four treatments, with two particle sizes of DDGS (640 vs. 450 microns) and two levels of pellet fines (0 vs. 25%). Mixed sex pigs (n = 760) were housed at Murphy-Brown’s research facility near Harrells, NC from July 18 to November 11, 2013. Housing consisted of a curtain sided barn with mechanical ventilation and totally slatted flooring. Diets were delivered and pen feed intake recorded using the FeedPro (Feedlogic Corp., Wilmar, MN) delivery system. In experiment 1, adding 30% DDGS to swine finishing diets improved modified PDI by 9.5%. Regrinding soybean meal improved modified PDI by 4.7% yet regrinding DDGS did not impact modified PDI. In experiment 2, neither regrinding DDGS nor level of pellet fines effected average daily gain, average daily feed intake or feed efficiency. Results suggest adding DDGS and regrinding soybean meal improves pellet quality in swine finishing diets. Yet regrinding DDGS is unnecessary.
Key findings:
• Diets containing 30% DDGS improved pellet durability index and modified pellet durability index by 1.6 and 9.5%, respectively in comparison to corn-soy based diets
• Regrinding soybean meal from 1070 to 470 microns improved pellet durability index and modified pellet durability index by 1.5% and 4.7%, respectively
• Regrinding DDGS from 680 to 480 microns did not impact pellet durability index and modified pellet durability index
• Regrinding DDGS did not impact average daily gain, average daily feed intake or feed efficiency
• Level of pellet fines (0 vs. 25%) did not influence average daily gain, average daily feed intake or feed efficiency