Feeding DDGS to Finishing Pigs in Deep-bedded Hoop Barns

Abstract

The objective of this study was to evaluate pelletted DDGS-based diets fed to finishing pigs in bedded hoop barns. Crossbred finishing pigs, average weight of 163 lb ± 1, were allocated to six pens with five barrows and five gilts per pen (n = 120). Trial 1 was conducted during January, February, and March 2007 at the ISU Western Research Farm, Castana, IA. Trial 2 was conducted during April, May, and June 2007. The pens were in small hoop barns (20 × 36 ft) with two pens per barn. Each pen was assigned to one of three dietary treatments—corn-soy, 20% DDGS, and 40% DDGS. The diets were pelletted and fed ad libitum. Recent plant analysis of DDGS was used in diet formulation. Diets were formulated to be equal in apparent digestible lysine (0.59%). The pellets were evaluated for quality (durability). Evaluation consisted of tumbling 1.1 lb of pellets for 10 minutes with four ¾-in. steel nuts. Quality was recorded as the amount of pellets remaining (relative to the amount of fines) compared with the initial amount of pellets. Durability of pellets was expressed as percentage of whole pellets left after the test. Pellet durability decreased as the percentage of DDGS increased. The diets had 78.9%, 66.8%, and 47.4% durability for the corn-soy, 20% DDGS, 40% DDGS diets, respectively. The pigs were allowed one week of adjustment to their pen and diet. The pigs were then continued in their respective pens on the assigned diets for six weeks. Two carcasses from each pen in Trial 2 were randomly selected for fatty acid and iodine value analyses. End weight averaged 266 lb ± 3 and did not differ (P = 0.36). Feed intake (ADFI) (P < 0.05) and growth (ADG) (P < 0.10) was depressed on the 40% DDGS diet. The feed intake was depressed more than the growth, probably because of the greater energy density of the DDGS. No major differences were noted in backfat BF, loin muscle area (LMA), carcass yield, or fat free lean percentage. The 40% DDGS-fed pigs required less feed per liveweight gain (F/G) and less feed per lean gain (P < 0.10) than the pigs fed the other diets. As DDGS in the diet increased, levels of palmitic and stearic fatty acids decreased and linoleic fatty acid increased. Iodine values were 64.7, 74.8, and 80.5 for the pigs fed the corn-soy, 20% DDGS, and 40% DDGS diets, respectively, suggesting that the 40% DDGS-fed pigs would produce unacceptable carcasses (soft fat). Pelleting may be a viable method to aid in the feeding of DDGS to pigs.