Dietary forage to concentrate ratios impact on yak ruminal microbiota and metabolites

Abstract

To improve the rumen fermentation function and growth performance of yaks (Bos grunniens), better understanding of the effect of different dietary forage to concentrate ratios on rumen microbiota and metabolites is needed. In the present study, three diets with different dietary forage to concentrate ratios (50:50, 65:35, and 80:20) were fed to 36 housed male yaks. The changes in the distribution of rumen microorganisms and metabolites and the interactions between them were studied by 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC–MS). The diversity and richness of microorganisms in the rumen varied according to diet. The most abundant phyla were Firmicutes and Bacteroidetes. Firmicutes was the most abundant in the C50 group, and the relative abundance of Bacteroidetes was significantly lower in the C65 group than in the C80 group (p < 0.05). The Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, and Methanobrevibacter had the highest relative abundances at the genus level. Among them, Christensenellace_R-7_group had the highest relative abundance in the C50 group. The Rikenellaceae_RC9_gut_group was significantly abundant in the C80 group compared with the C50 group. The Methanobrevibacter content was higher in the C65 group than in the other two groups. Both the concentration and metabolic pathways of rumen metabolites were influenced by the dietary concentrate ratio; lipids, lipid-like molecules, organic acid metabolites, and organic oxide-related metabolites differed between the groups. Significant changes were found for six metabolic pathways, including arginine and proline metabolism; glycine, serine, and threonine metabolism; glyoxylate and dicarboxylate metabolism; arginine biosynthesis; glycerophospholipid metabolism; glycerolipid metabolism; and nitrogen metabolism.

Deciphering the Impact of Nutrient Composition and Tissue Structure on Rumen Microbiome Dynamics in Roughage Degradation

“…This trend suggests microbial competition for nutrients during the early fermentation stage [68], succeeded by enhanced growth due to nutrient release from cellulose degradation in later fermentation phases [69]. The KEGG pathways analysis revealed that carbohydrate metabolism [70], amino acid metabolism [71], and energy metabolism pathways [71] had elevated relative abundances, underscoring their significance in the degradation of various roughage types [72]. Notably, ABC transporters were the most abundant functional pathway at level-3, indicating the diverse substrate-binding capabilities of the rumen microbiota [73,74].…”

The Effect of Yucca schidigera Extract on Serum Metabolites of Angus Crossbreed Steers with Metabolomics

“…Furthermore, Yi et al [ 30 ] found that YSE reduced the relative abundance of Bacillota and increased the relative abundance of Bacteroidota . Bacteroidota was mainly involved in the degradation of non-fibrous polysaccharides, while Bacillus was mainly involved in the catabolism of fibrous polysaccharides [ 31 , 32 ]. After cellulose is broken down by the cellulase produced by Bacillota , then Bacteroidota can efficiently use glucans, fructans, xylans, and arabinans because they have more genes encoding glycoside hydrolase and polysaccharide lyase [ 33 ].…”

Effects of dietary crude protein levels in the concentrate supplement after grazing on rumen microbiota and metabolites by using metagenomics and metabolomics in Jersey-yak

“…The ratio of Acetate/Propionate in the rumen is different with different feed types or microbial community structures. The higher the proportion of concentrate in the ruminant diet, the lower the ratio of Acetate/Propionate ( Pang et al, 2022a ; Yi et al, 2022a ). In this experiment, the ratio of Acetate/Propionate in the control group was higher than that in the LP and the HP group, which was consistent with the results of Dai et al (2022) .…”

“…Although the effects of dietary nutrient levels on rumen microbials and metabolites in ruminants have been extensively studied, most of them are limited to the level of rumen bacteria using techniques such as 16S rRNA. Moreover, due to the differences in digestive and metabolic characteristics and environmental adaptability between Jersey cattle, yak, and other cattle species, the effects on microbial communities and metabolites may also be different ( Latham et al, 2018 ; Li et al, 2022 ; Pang et al, 2022a ). With the deepening of microbial research, people gradually combine metagenomics and metabonomics to explore the effects of dietary nutrition level on host traits and rumen microbial community, ( Xue et al, 2020 , 2022a ).…”