Biofuel co-products as livestock feed - Opportunities and challenges

214Biofuel co-products as livestock feed – Opportunities and challengesacross treatments. Feeding a mixture of DDGS and RSMresulted in the highest weight gain (1.46 kg/day) comparedwith SBM, RSM or DDGS (1.31 kg/day; Meyer et al., 2010).The results of the experiments with fattening bulls showedthat DDGS as the main protein source compares well withother protein supplements and is able to sustain high productiveperformance. This also indicates that differencesbetween CP sources regarding the amino acid pattern ofthe ruminally undegraded CP (RUP) was not a constraintfor intensive growth.Nutritive value and feeding to non-ruminants –pigsCo-products from biofuel production, such as DDGS,have also been fed to non-ruminant animals, particularlypigs (e.g. Lindermayer, 2004; Richter et al., 2006a; Berk,2007; Hackl et al., 2007; Berk, Lebzien and Flachowsky,2008; Kluge and Kluth, 2008) and poultry (e.g. Dammeand Pegeanova, 2006; Richter et al., 2006b; Trautwein etal., 2008). Patience et al. (2007) summarized mainly NorthAmerican results from feeding studies with DDGS in pigs.Some authors investigated the amino acid pattern ofDDGS and its praecaecal digestibility in pigs (e.g. Richteret al., 2006a; Hackl, Priepke and Henning, 2007; Hacklet al., 2007; Kluth, Wolf and Rodehutscord, 2009). Hackl,Priepke and Henning (2007) and Hackl et al. (2007) studieda wheat DDGS with 386 g CP per kg DM. Comparedwith wheat (32 g lysine per kg CP), DDGS contained only17 g lysine per kg CP. The low concentration and the lowpraecaecal digestibility coefficient of lysine in wheat-DDGS(0.69 compared with 0.872 for wheat) underline the significanceof lysine as the first limiting amino acid in DDGSfor pigs. Although DDGS contains about 2.5–3 times moreCP than wheat, it has only 1–1.5 times the concentrationof praecaecally digestible lysine. Very low praecaecal digestibilitieshave been reported by Hackl, Priepke and Henning(2007) and Hackl et al. (2007) only for sulphur-containingamino acids (0.67–0.69), but not for most of the otheressential amino acids. In broilers, however, Kluth, Wolf andRodehutscord (2009) measured a praecaecal digestibilitycoefficient for lysine in DDGS of 0.79.In a feeding trial with 80 growing-finishing pigs (40females and 40 castrated males) from 35 kg initial liveweight up to 115 kg slaughter weight, Berk (2007) partiallyreplaced SBM and/or RSM by DDGS or a DDGS/RSM mix(Table 7). The feed in mash form and drinking water wereoffered for ad lib intake. Feed intake, total weight andslaughtering results were not influenced (P >0.05) by proteinsource. From this data it can be concluded that DDGScan partially replace SBM in diets for growing-finishing pigsin intensive production systems.Richter et al. (2006a) carried out four feeding trialswith piglets (0–100 g/kg DDGS in the diet; Table 8) as wellthree trials with growing-finishing pigs (0–250 g/kg DDGSin the diet; Table 9). The authors concluded that pigletsbelow 10 kg live weight should not consume DDGS, anddiets of heavier animals could receive DDGS up to 100 g/kg diet.The results suggest that DDGS up to 200 g/kg in thediet of grower-finisher pigs did not influence performance.The lower recommended inclusion level for piglets ismost likely due to the low lysine content of the DDGS.Hence, higher inclusion levels may be possible if lysinelevels are adjusted accordingly. Kluge and Kluth (2008),Punz, Windisch and Schedle (2010) and Schedle, Mair andWindisch (2010) replaced SBM in grower-finisher dietscompletely by DDGS, and observed no adverse effect onfattening and slaughtering variables. Additional non-starchTABLE 7Protein sources for grower or finishers, feed intake, daily weight gain and some slaughter data for pigsProtein source Animal Soybean Soybean/RSM Soybean/DDGS SBM+RSM +DDGSSoybean meal Grower 15.0 6.0 8.0 6.0Finisher 11.0 – 5.0 3.0Rapeseed meal Grower – 10.0 – 5.0Finisher – 15.0 – 6.0DDGS Grower – – 8.0 5.0Finisher – – 10.0 6.0Crude protein (g/kg DM) Grower 178 176 178 175Finisher 163 166 166 169Feed intake (kg/animal/day) total 2.83 2.81 2.83 2.76Weight gain (g/animal/day) 1010 959 998 940Lean meat (%) 54.4 55.6 54.7 55.7Backfat thickness (mm) 29.0 28.0 28.4 25.1Backfat fatty acids (% of total)SFA 40.5 40.1 41.1 39.2MUFA 47.4 49.5 46.8 48.8.PUFA 12.1 10.4 12.0 12.4Notes: SBM = soybean meal; RSM = rapeseed meal; DDGS = dried distillers grain with solubles; SFA = short-chain fatty acids; MUFA = mono-unsaturatedfatty acids; PUFA = polyunsaturated fatty acids. Source: Berk, 2007.