Dry whole corn optimizes rumen fermentation and gastrointestinal nutrient digestion in sheep by regulating cazymes-microbial synergy in the rumen

Processing corn grain alters its ruminal degradation rate and nutritional value in small ruminants. In this study, feeding DWC to sheep prolonged ruminal retention time compared with DRC or DGC, resulting in slower, more sustained starch release. This led to higher total-tract and foregut starch digestibility, increased ruminal propionate production, enrichment of starch-degrading bacteria (e.g., Bacteroides and Pseudobutyrivibrio spp.) and carbohydrate-active enzymes, and reduced starch flow and fermentation intensity in the hindgut. No differences were observed in blood parameters. Overall, DWC optimized energy utilization and rumen health, supporting its use in high-starch diets for sheep and potentially other small ruminants such as dairy goats.