Nutritional Impact Of Feeding Liquid Ethanol Co-Products And Barley Supplementation To Wean-To-Finish Pigs On Growth Performance And Carcass Characteristics

Abstract

The first objective of this study was to compare dry and liquid feeding systems (The Big Dutchman, Holland, MI, USA) on growth performance in nursery pigs. Four-hundred and eighty early weaned pigs (N=480; initial BW 6.1 ± 0.17 kg; 18 d old; Topigs Norsvin female X Compart Duroc boar) were blocked by weight and randomly assigned to one of two dietary treatment groups via a randomized complete block design (n=240; 10 pigs/pen; 24 pens/treatment). Diets were formulated to be isocaloric and isonitrogenous: (1) Dry, corn-soybean meal. (2) Liquid, water and corn-soybean meal (DM 23%). Pig weights were recorded on d0, d14, d28, and d42 indicating the end of the nursery period. Performance parameters average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency measured as gain-to-feed (G:F) were calculated on pen basis. Data were analyzed using PROC-MIXED procedure of SAS. Statistical significance was set at P ≤ 0.05. Pigs in the dry feeding system had greater ADG, G:F, and final BW (P<0.01). Initially, dry diets had greater ADFI (P<0.01). By the end of the nursery period, liquid fed pigs had greater ADFI than dry fed pigs (P<0.01) In conclusion, feeding nursery pigs dry corn-soybean meal diets resulted in greater ADG and G:F which led to heavier final BW when compared to liquid feeding system pigs (P<0.01). The second objective was to measure nitrogen (N), phosphorus (P), and energy digestibility when feeding the ethanol co-products Dried Distillers Grain with Solubles (DDGS), Corn Distillers Whole Stillage (CDWS), and Corn Condensed Distillers Solubles (CCDS) to growing swine, and to determine the nutrient profile of manure slurry. Thirty-two crossbred barrows (N=32; Topigs Norsvin females X Compart Duroc boars) were selected with a mean initial body weight of 82.5 kg (Final BW 85.1 kg), housed individually in stainless steel metabolism crates, and were randomly assigned to 1 of 4 dietary treatments (n=8): (1) Dry, control corn-soybean meal (2) Dry, control with 30% DDGS (3) Liquid, control corn-soybean meal and water (4) Liquid, control basemix with 20% CCDS and 30% CDWS. Pigs were allowed 4 days for adaptation to crates with 4 days of sample collection including urine, feces, and slurry. Slurry was pooled and allowed to sit to mimic anaerobic pit conditions. Results from this study found that feeding ethanol co-products attained similar N intake and digestible N levels when compared to conventional corn-SBM diets. Feeding ethanol co-products had greater P intake while liquid diets were greater for digestible P (P<0.01). Dry diets were greater for energy intake and DE while feeding CCDS and CDWS reduced energy availability (P<0.01). For slurry characteristics, dry diets were greater in total N and P while being similar in K content (P<0.01). Pigs fed DDGS had the greatest concentration of sulfur in slurry. In conclusion, feeding liquid ethanol co-products can be an alternative to traditional grains for meeting dietary requirements. Furthermore, pigs fed ethanol co-products yield slurry with comparable nutrient content to corn-SBM and have potential as an alternative to crop fertilizer. The third objective was to compare feeding DDGS, CDWS, CCDS, and barley to grow-finish swine in terms of growth performance and carcass characteristics. The fourth objective was to determine the effect of partial replacement of ethanol co-products with barley on belly firmness. Four-hundred and eighty pigs were blocked by weight (25.8 ± 0.43 kg) and randomly assigned to one of six dietary treatment groups via randomized complete block design (N=480; n=80; 10 pigs/pen; 8 pens/treatment). Diets: (1) Dry basal, Control, corn-SBM all phases (2) Dry, DDGS (Phase 1: 20%, Phases 2-4: 30%). (3) Dry, DDGS (Phase 1: 20%, Phases 2 and 3: 30%, Phase 4: 15% DDGS + 15% barley). (4) Liquid basal, control, corn-SBM and water all phases (5) Liquid, Ethanol co-products (Phase 1:16% CCDS + 24% CDWS, Phases 2 and 3: 20% CCDS + 30% CDWS, Phase 4: 24% CCDS + 36% CDWS). (6) Liquid, Ethanol co-products (Phase 1:16% CCDS + 24% CDWS, Phases 2 and 3: 20% CCDS + 30% CDWS, Phase 4: 15% CCDS + 30% CDWS + 15% barley). Pigs were weighed on d0, d28, d56, d84, and d112. Pigs were marketed at 127 kg, therefore liquid fed pigs were allowed two more weeks to meet market weight, and weighed on d126. Growth performance parameters ADG, ADFI, and G:F were calculated on pen basis. Carcasses were measured for hot carcass weight (HCW), fat depth, loin depth, percent lean, and dressing percentage. Across all diets, feeding dry corn-SBM had the greatest performance for final BW, ADG, and G:F (P<0.01). Furthermore, pigs fed barley had reduced ADG and ADFI and lesser loin depth (P<0.01). Feeding DDGS had similar performance however belly firmness was reduced (P<0.01). Feeding liquid ethanol co-products resulted in greater G:F and reduced ADFI when compared to liquid corn-SBM diets (P<0.01). For pigs fed ethanol co-products such as DDGS, CCDS, and CDWS, belly firmness was reduced due to the greater level of poly-unsaturated fatty acids (PUFA) and iodine value (IV) leading to softer bellies (P<0.01). In conclusion, dry feeding was superior in growth performance and carcass merit as they reached market readiness compared to liquid fed pigs. Feeding ethanol co-products is an effective cost savings strategy, however, belly firmness may become an issue with the current feeding method. (Key words: pigs, whole stillage, condensed distillers solubles, ethanol co-products, growth performance, nutrient digestibility, carcass characteristics, belly firmness)