Effects of Grape Pomace Complete Pellet Feed on Growth Performance, Fatty Acid Composition, and Rumen Fungal Composition in Beef Cattle

Grape pomace, a winemaking byproduct, is nutrient- and polyphenol-rich, but research on its use in beef cattle is limited. This study explored the impact of grape pomace-based complete pellet feed on growth, serum biochemistry, fatty acid profile, and rumen microbiota in beef cattle. Fifteen healthy Simmental cattle were randomly divided into three groups (G0, G15, and G20) and fed a complete pelleted ration containing 0%, 15%, and 20% of grape pomace, respectively, for 60 days. The results showed that the addition of grape pomace to the ration markedly increased the average daily feed intake and average daily weight gain in beef cattle. In terms of biochemistry, the levels of total protein (TP) and albumin (ALB) in the G20 group were higher than in the G0 group (<i>p</i> > 0.05). The levels of oleic acid, linoleic acid, and behenic acid were higher in the G20 group than in the G0 group. Grape pomace had no significant effect on rumen fungal diversity and total volatile fatty acids (TVFAs) in beef cattle. The pH and ammonia nitrogen content in the G15 and G20 groups were significantly higher than that in the G0 group. This indicates that grape pomace can be used as feed raw material for beef cattle.