Corn and sorghum distiller grains in sheep diets

Dried distiller grains (DDG) represent a protein source alternative in animal feed, but the variation from sources and dietary inclusion level can affect animal nutrition response. We evaluated the effects of replacing soybean meal (SBM) with corn and sorghum DDG in the diet on intake, digestibility, allantoin urinary excretion, and nitrogen (N) balance in sheep. Ten intact male sheep, with body weight (BW) of 22.3 +/- 2.7 kg were blocked by BW in two replicated 5 x 5 Latin squares. Each period lasted 15 d and consisted of 10 d for diet adaptation and 5 d for sampling and data collection. We evaluated five isonitrogenous diets in a factorial arrangement (2 x 2 + 1): two DDG sources (corn or sorghum DDG); two DDG levels in diets (150 and 300 g /kg dry matter (DM) diet), and a control diet (corn grain and soybean meal as concentrate sources). Inclusion of DDG (DDG versus control) did not affect dry or organic matter intake, but it reduced crude protein (CP) and organic matter (OM) apparent totaltract digestibilities, and digestible OM intake. No effects of DDG inclusion were observed on allantoin urinary excretion and N balance. No interactions between DDG source and level were detected in all response variables. Sorghum-DDG diets had lower CP apparent total-tract digestibility than corn-DDG diet, and N body retention efficiency 20% lower. Dried distiller grains level increase of 150-300 g/kg DM diet reduced CP and OM apparent total-tract digestibilities, and digestible OM intake. Sorghum-DDG has protein biology value for ruminant 20% lower than corn-DDG, and 150 g DDG/kg DM seems more appropriate inclusion than 300 g DDG/kg DM diet. Replacing a mixture of SBM and corn with DDG reduces the nutritional value of the diet, but the effect depends on the level and source of DDG.