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

Abstract

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, monounsaturated 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.Key words: Lamb, corn, wheat, triticale, distillers’ grains, performance, carcass characteristics