Effects of corn-, wheat- or triticale dry distillers' grains with solubles on in vitro fermentation, growth performance and carcass traits of lambs

McKeown, L. E., Chaves, A. V., Oba, M., Dugan, M. E. R., Okine, E. and McAllister, T. A. 2010. Effects of corn-, wheat- or triticale dry distillers' grains with solubles on in vitro fermentation, growth performance and carcass traits of lambs. Can. J. Anim. Sci. 90: 99-108. The objective of this study was to determine the effect of replacing a mixture of canola meal and barley grain with corn-, wheat- or triticale dry distillers' grains with solubles (DDGS) at 20% of dietary dry matter (DM) on in vitro ruminal fermentation in bovine ruminal fluid and on growth performance and carcass characteristics of lambs. Sixty ram lambs (22.6 +/- 3.0 kg) were randomly assigned to one of four dietary treatments and given individual ad libitum access to feed until they attained slaughter weight. The control diet consisted (DM basis) of 54% barley grain, 16% sunflower hulls; 11.5% beet pulp, 10% canola meal, 2.5% canola oil and 6.0% molasses, vitamins and minerals mixture. For the three DDGS dietary treatments, 10% barley grain and 10% canola meal were replaced with 20% corn-, wheat-or triticale-DDGS. The source of DDGS did not influence (P >0.51) dry matter intake (DMI) or average daily gain (ADG). Feed conversion (feed:gain) of lambs fed wheat DDGS was approx. 12% poorer (P <0.05) than that of lambs fed control or corn DDGS diets. In vitro data suggest that the inefficient gain may have been attributable to greater (P <0.05) ammonia concentration at 24 h and lower digestibility of wheat DDGS. Carcass traits, including hot carcass weight, body wall thickness and saleable meat yield, were not affected (P >0.60) by dietary treatment. Total saturated, mono-unsaturated and polyunsaturated fatty acids in subcutaneous fat were also not affected by DGGS source (P >= 0.13). There was no treatment effect (P =0.33) on concentrations of t11-18:1, but feeding triticale DDGS increased the concentration (P =0.04) of c9, t11-conjugated linoleic acid (CLA). In conclusion, DDGS from corn, wheat or triticale can replace a mixture of barley grain and canola meal at 20% of dietary DM without adversely affecting DMI. ADG or carcass characteristics of growing lambs, although wheat DDGS may reduce feed conversion ratio (feed:gain). Including triticale DDGS may also improve the fatty acid profile of subcutaneous fat.