The present study evaluated the effect of dietary supplementation with fermented-Moutai distillers' grain (FMDG) on the growth performance, meat quality, amino acid composition and blood metabolites of finishing cattle. Thirty cattle (2 years old; 237.55 ± 10.72 kg) were randomly assigned to one of three dietary supplementations: 0% FMDG (control), 15% FMDG (R1) and 30% FMDG (R2) [dry matter (DM) basis]. After 60 days, the inclusion of FMDG had no significant (p > 0.05) effects on the growth performance indices (dry matter intake, average daily gain and feed efficiency), meat quality (cooking yield, shear force, L*, a*, and b* values) or bovine blood biochemical indicators (except albumin and immunoglobulin A). Cattle fed R1 had the lowest (p = 0.001) loin eye area. Supplementation with FMDG significantly (p < 0.05) increased the beef contents of various amino acids (except isoleucine and arginine) compared with the control diet. Specifically, R2 significantly increased (p < 0.05) the total amino acid, essential amino acid, non-essential amino acid and umami amino acid contents in beef, while the difference in bitter amino acid content between different treatments was not significant (p = 0.165). These results suggest that it is feasible to include FMDG at up to 30% DM without affecting the growth performance, meat quality or blood metabolites of finishing cattle.

Dried distiller’s grains with solubles (DDGS) are rich in nutrients and can enhance animals’ growth and immunity. However, there are few reports on the effects of a diet of DDGS on plasma metabolism and the related action pathways in domestic animals. In this study, groups of Guanling yellow cattle (GY) and Guanling crossbred cattle (GC) having a basal diet served as the control groups (GY-CG and GC-CG), and DDGS replacing 25% of the diet of GY and GC served as the replacement groups (GY-RG and GC-RG), with three cattle in each group. Plasma samples were prepared for metabolomic analysis. Based on multivariate statistical and univariate analyses, differential metabolites and metabolic pathways were explored. Twenty-nine significantly different metabolites (p < 0.05) were screened in GY-RG compared with those in GY-CG and were found to be enriched in the metabolic pathways, including choline metabolism in cancer, linolenic acid metabolism, and amino acid metabolism. Nine metabolites showed significant differences (p < 0.05) between GC-RG and GC-CG and were mainly distributed in the metabolic pathways of choline metabolism in cancer, glycerophospholipid metabolism, prostate cancer metabolism, and gonadotropin-releasing hormone (GnRH) secretion. These results suggest that a DDGS diet may promote healthy growth and development of experimental cattle by modulating these metabolic pathways. Our findings not only shed light on the nutritional effects of the DDGS diet and its underlying mechanisms related to metabolism but also provide scientific reference for the feed utilization of DDGS.

In this research we evaluated the effect of exogenous lactic acid bacteria (LAB) and Amomum villosum essential oil (AVEO) on the chemical composition, microbial community composition, microbial functional diversity, and fermentation quality of Broussonetia papyrifera (BP) and Pennisetum sinese (PS) mixed silages. The BP: PS mixing ratios were 100:0, 70:30, 50:50, 30:70, and 0:100. After 3 and 30 days of ensiling at 22–25°C, microbial diversity and function, and fermentation quality, was assessed. Increasing PS content resulted in decreased ammoniacal nitrogen and pH, increased water-soluble carbohydrate content, increased relative abundance of Lactococcus and Acinetobacter, and reduced relative abundance of Caproiciproducens and Pseudomonas. A 50:50 BP: PS ratio effectively improved the fermentation quality compared to anaerobic fermentation with BP or PS alone, while AVEO treatment further improved fermentation quality by increasing Lactococcus relative abundance. Moreover, as fermentation proceeded, ensiling enhanced the “Human diseases”, “Environmental information processing”, and “Cellular processes” functions at the first level, as well as the “Two-component system” and “ABC transporters” functions at the third level. Different additives affected the fermentation of BP and PS mixed silage by regulating microbial community succession and metabolic pathways during ensiling.