Whole-Plant Corn Silage Improves Rumen Fermentation and Growth Performance of Beef Cattle by Altering Rumen Microbiota
Abstract BackgroundIn recent years, whole-plant corn silage had been widely used in China. Roughage was an important source of nutrition for ruminants and had an important effect on rumen microbiota, which plays an important role in animal growth performance and feed digestion. To better understand the effects of different silages on rumen microbiota, the effects of whole-plant corn silage or corn straw silage on growth performance, rumen fermentation products, and rumen microbiota of Simmental hybrid cattle were studied. Results60 healthy Simmental hybrid cattle were randomly divided into 2 groups with 6 repeats in each group and 5 cattle in each group. They were fed with whole-plant corn silage (WS) diet and corn straw silage (CS) diet respectively. Compared with corn straw silage, whole-plant corn silage significantly increased daily gain and decreased feed-weight ratio of beef cattle. Whole-plant corn silage also decreased the acetic acid in the rumen and the acetate to propionate (A/P) ratio compared with corn straw silage. At the genus level, the relative abundance of Prevotella_1 was significantly increased while the relative abundance of Succinivibrionaceae_UCG-002, Succiniclasticum, norank_f_Bacteroidales_RF16_group, and Ruminococcus_1 was decreased in cattle fed whole-plant corn silage compared with those fed corn straw silage. Prevotella_1 was positively correlated with acetic acid and A/P ratio, Succinivibrionaceae_UCG-002 was positively correlated with propionic acid and butyric acid, and negatively correlated with pH, Succiniclasticum was positively correlated with pH and A/P ratio, and norank_f__F082 and Rikenellaceae_RC9_gut_group were positively correlated with pH, propionic acid and butyric acid. Feeding whole-plant corn silage improved amino acid metabolism, nucleotide metabolism, and metabolism of beef cattle compared with feeding corn straw silage. Correlation analysis between rumen microbiota and metabolic pathways showed that Succinivibrionaceae_UCG-002 was negatively correlated with Carbohydrate Metabolism, Glycan Biosynthesis, and Metabolism, while Prevotellaceae_UCG-003 was positively correlated with Amino Acid Metabolism, and Carbohydrate Metabolism. ConclusionsFeeding whole-plant corn silage can improve the production performance rumen fermentation of beef cattle by altering rumen microbiota, amino acid metabolism, and nucleotide metabolism.