Effects of Replacing Corn and Soybean Meal with Dried Distillers Grains with Solubles on Blood Metabolites, Milk Yield and Composition of Dairy Goats during Late Lactation

In the southern USA, warm season grasses make up the bulk of the roughage consumed by livestock including small ruminants. Digestibility of grasses generally declines with maturity, such that these forages may not always provide the necessary nutrients to support optimal animal performance or maintain product quality. Supplementation with protein and moderate level of grain generally increases forage intake and digestibility. The diversion of corn away from human and animal feed for biofuel production has created a need for alternative energy supplements. Dried distillers grains with solubles (DDGS), high in bypass protein and digestible fiber, is a good alternative to replace corn and soybean meal (SBM) in small ruminant diets. The objective of this study was to determine intake, blood metabolites, milk yield and composition of Alpine and Saanen dairy goats, in late lactation, consuming ground eastern gamagrass (EGG; Tripsacum dactyloides L.) or Bermudagrass hay (BG; Cynodon dactylon) supplemented with DDGS or corn and SBM. The does were stratified based on milk yield and allotted to four groups. The groups were randomly assigned to one of four treatments (9 does/trt). The does were group fed daily to allow ad libitum intake. The supplement and hay was mixed together and consumed by the does. The trial lasted 19 days. Blood plasma samples from each animal were analyzed for plasma urea nitrogen (PUN), glucose, and NEFA concentrations. Combined morning and evening milk samples were analyzed for protein, fat, lactose and total solids. Data were analyzed as a mixed model for a completely randomized design using SAS. Replacing corn and SBM with DDGS did not affect (P > 0.05) milk yield (0.93 ± 0.155 kg) plasma glucose, milk protein or lactose. However PUN and milk fat were significantly different (P < 0.05). BG increased PUN (37.02 and 35.04 ± 1.71 mg/dL) relative to EGG treatments (29 and 32.6 ± 1.71 mg/dL). Supplementing EGG with DDGS increased the NEFA concentration (209.3 ± 22.02 µEq/L) compared to BG and EGG with corn supplementation (120.6; 114.3; and 126.8 ± 22.02 µEq/L). Replacing corn with DDGS over a short feeding period does not affect milk yield and its basic components.