Validation of ME prediction equations and the impact of feeding diets containing corn distillers dried grain with solubles (DDGS) with variable oil content on growth performance of growing-finishing pigs

Abstract Text:

Previous studies have demonstrated that ether extract (EE) concentration poorly predicts ME content among DDGS sources. Equations to predict ME content in DDGS have been developed and published, but not validated. The objective of this experiment was to determine growth performance and carcass composition responses of growing-finishing pigs fed diets containing DDGS with similar predicted ME concentrations, but variable concentrations of EE (% as fed basis). Pigs (n = 432) were blocked by initial BW (25.8 ± 0.4 kg) and, within blocks, pens were allotted randomly to 1 of 4 diets (9 pigs/pen, 12 replicates/treatment) in a 4-phase feeding program. Dietary treatments consisted of: 1) corn-soybean meal (CON), 2) 40% low-oil DDGS (5.9% EE; LOW), 3) 40% medium-oil DDGS (9.9% EE; MED), and 4) 40% high-oil DDGS (14.2% EE; HIGH). Diets contained similar standardized ileal digestible AA and digestible P within phase, but ME content of CON diets was higher than LOW, MED, and HIGH diets. Data for ADFI, ADG, and G:F were analyzed as repeated measures using MIXED procedure of SAS, with pen and block as random effects and diet as the fixed effect. Overall ADFI of pigs fed CON was greater (P < 0.05) than MED and HIGH, but not different from LOW. Overall ADG of pigs fed LOW, MED, and HIGH was not different, but lower (P < 0.05) than pigs fed CON. However, pigs fed LOW had reduced (P < 0.05) G:F compared with the other treatments. Pigs fed CON had greater (P< 0.05) HCW, dressing percentage, backfat depth, and loin muscle area than those fed the DDGS diets, but there were no differences among DDGS treatments. No treatment differences were observed for percentage of carcass fat-free lean. In conclusion, DDGS EE content did not affect growth performance and carcass composition of growing-finishing pigs, but the ME prediction equation overestimated ME content of low-oil DDGS based on reduced G:F, compared with the medium and high-oil DDGS sources.

		40% DDGS
	CON	LOW	MED	HIGH	SEM
Predicted ME in DDGS, kcal/kg1		3,346	3,422	3,319
ADFI, kg	2.72a	2.65ab	2.61b	2.60b	0.029
ADG, kg	0.97a	0.92b	0.92b	0.93b	0.009
G:F	0.368a	0.356b	0.365a	0.367a	0.003
1Predicted ME (kcal/kg, DM basis) = -261 + 1.05DE - 7.89CP + 2.47NDF - 4.99EE. DE = -2,161 + 1.39GE - 20.7NDF - 49.3EE. GE = 4,583 + 50.61EE - 0.12 × Particle Size.

Keywords: distillers dried grains with solubles, ME prediction, pigs