PSVII-8 Efficacy of corn dried distillers grains with solubles as a replacement for soybean meal in a Boer goat diet

Due to increased use of dried distillers grains with solubles (DDGS) in animal feed and accessibility of ethanol plants in the Midwest, this study evaluated the effect of feeding DDGS in place of soybean meal (SBM) on the fecal microbiome of Boer goats. Twenty-four Boer goat kids (apx. 70 d of age; 28.21 ± 0.96 kg) were blocked by BW and randomly assigned to 1 of 2 treatment diets for 47 d. Treatments were 0% (0DDGS) and 100% (30DDGS) DDGS in place of SBM. Goats were placed in 8 pens (4 pens/treatment; 3 goats/pen) with ad libitum access to feed and water. Fecal pellets were collected on d 47 via rectal grab and stored at -80°C until microbiome sequencing was performed. The V4 region of the 16S rRNA gene was sequenced by MR DNA (MR DNA, Shallowater, TX) on the Illumina HiSeq 2500 platform (Illumina, Inc., San Diego, CA). Data were analyzed using ANOVA with Tukey’s test for pairwise comparisons. Genera impacted by DDGS inclusion with individual relative abundances greater than 1% included increased Ruminococcus (P = 0.01) and Methanobrevibacter (P = 0.009) and decreased Lachnoclostridium (P = 0.02). Ruminococcus and Methanobrevibacter most likely increased in 30DDGS due to greater amounts of soluble fiber passing through the rumen, thus being fermented in the hindgut. The overall percentage of the phyla Bacteroidetes (P = 0.36) and Firmicutes (P = 0.12) did not differ between treatments; however, Firmicutes:Bacteroidetes increased (P = 0.05) in the 30DDGS diet. Treatment did not impact β-diversity (P = 0.47) although species richness increased (P = 0.09) in DDGS-fed goats as more soluble fiber was available for fermentation in the hindgut. In all, results of this study found replacing SBM with DDGS did not greatly alter the fecal microbiome of Boer goats.