Dietary Energy Levels Affect Carbohydrate Metabolism-Related Bacteria and Improve Meat Quality in the Longissimus Thoracis Muscle of Yak (Bos grunniens)

Abstract

The effects of different dietary energy levels on the ruminal bacterial population, selected meat quality indices, and their relationship in yak longissimus thoracis (LT) muscle were assessed in this study. A total of 15 castrated yaks were randomly assigned to three groups with low- (NEg: 5.5 MJ/Kg, LE), medium- (NEg: 6.2 MJ/Kg, ME), and high- (NEg: 6.9 MJ/Kg, HE) dietary energy levels and occurred in the cold season (March to May). All yaks from each treatment group were humanely slaughtered and sampled on the day of completion of their feeding treatment. The results showed that the water content and crude fat levels of the LT muscle were markedly elevated in the HE group (P < 0.05), while the shear force was drastically reduced (P = 0.001). Methionine, aspartic acid, and glycine levels in the LT muscle were higher in the LE group compared with the ME and HE groups (P < 0.05). The glutamic acid level in the ME group was greater in comparison to the LE and HE groups (P < 0.05), while the histidine level in the ME group was higher than that in the HE group (P < 0.05). Additionally, the HE diet significantly elevated (P < 0.05) the abundance of carbohydrate metabolism-associated bacteria including Prevotella_1, Lachnospiraceae_NK4A136_group, U29_B03, Ruminiclostridium_6, and Ruminococcaceae_UCG_013 in the rumen. The results of the Spearman's rank correlation analysis showed that the abundance of uncultured_bacterium_f_vadinBE97 and uncultured_bacterium_f_Lachnospiraceae showed a significant influence on the indicator of IMF and SF. In conclusion, a high dietary energy level improved the meat quality in the LT muscle of yak mainly by increasing the relative abundance of ruminal amylolytic bacteria to provide substrates for fatty acid synthesis.

Metabolomics approach reveals high energy diet improves the quality and enhances the flavor of black Tibetan sheep meat by altering the composition of rumen microbiota

“…In the previous research, we discovered that indoor feeding increased the content of fat in sheep's LL by regulating the lipolysis in the adipocyte pathways of muscles ( 10 ). Moreover, previous reports show that the increased carbohydrate metabolism could generate more energy and substrate for the host for the synthesis of fat in muscles ( 38 , 39 ). In this study, we found a strong correlation between the fat content and the metabolism of lipids (ether lipid, glycerolipid, and glycerophospholipid) and carbohydrates (carbohydrate digestion and absorption, sucrose and starch, and galactose).…”

“…This result eventually produced the difference in metabolic levels in the muscle due to a direct correlation amid the abundance of four species at the genus level ( Quinella, Ruminococcus 2, Succinivibrionaceae UCG-001, and (Eubacterium) coprostanoligenes ) and the content of the products of carbohydrate metabolism (stachyose, isomaltose, D-lactose, and maltotrios) in the LL. The high energy supply promoted the rapid proliferation of these bacteria, which in turn degrade carbohydrates ( 38 ). This process provides substrates and energy to fat synthesis and VOCs formation in the LL and thus, generates better mouthfeel, nutrition, and flavor of Black Tibetan sheep mutton.…”

Metabolome and microbiome analysis revealed the effect mechanism of different feeding modes on the meat quality of Black Tibetan sheep

“…As such, it was a better choice for producing healthy mutton products (Wang et al, 2021). Furthermore, Du et al (2021) found that a high-energy diet could enhance yak's muscle quality, including fat content and shear force of the LL. This was achieved through an increase in amylolytic bacteria and their fermentation products which were required for fatty acid synthesis (Du et al, 2021).…”

“…Furthermore, Du et al (2021) found that a high-energy diet could enhance yak's muscle quality, including fat content and shear force of the LL. This was achieved through an increase in amylolytic bacteria and their fermentation products which were required for fatty acid synthesis (Du et al, 2021). Most importantly though, the current authors previously reported that a high-energy diet could affect Black Tibetan sheep's muscle metabolism by altering the composition of rumen microbiota, with this change improving meat quality and flavor (Zhang et al, 2022).…”

Effect of Supplementary Levels of Rumen-Protected Lysine and Methionine on Growth Performance, Carcass Traits, and Meat Quality in Feedlot Yaks (Bos grunniens)

“…Recent studies observed that dietary N utilization was improved in beef cattle as a result of the supplementation with rumen-protected methionine (RPM) [ 13 , 14 ]. Furthermore, Liu et al reported [ 15 ] that supplementation with RPL and RPM could affect rumen bacterial communities, which was positively associated with improved meat quality in yaks [ 16 ]. Cao et al [ 17 ] demonstrated that the addition of RPL and RPM to the diet also had a positive effect on growth performance of yak calves.…”