Metabonomic Responses of Grazing Yak to Different Concentrate Supplementations in Cold Season

Abstract

Supplementation plays an important role in reversing the weight loss of grazing yaks during cold season. However, little is known about the effect of supplementation on the serum metabolites of grazing yaks. The objective of this study was to explore the effects of supplementary feeding on average daily gain (ADG) and serum metabolites with nuclear magnetic resonance (NMR)-based metabolomics method in growing yaks during cold season on the Qinghai-Tibetan plateau. Twenty 1.5-year-old female yaks (91.38 ± 10.43 kg LW) were evenly divided into three treatment groups and a control group (CON) (n = 5 per group). All the yaks were released to graze during daytime, whereas the yaks in the treatment groups were supplemented with highland barley (HLB), rapeseed meal (RSM), and highland barley plus rapeseed meal (HLB + RSM) at night. The whole experiment lasted for 120 days. Results indicated that the ADG of growing yak heifers was increased by concentrate supplementations, and ADG under HLB and HLB + RSM group was 37.5% higher (p < 0.05) than that with RSM supplementation. Supplementary feeding increased the plasma concentrations of total protein (TP), albumin (ALB), and blood urea nitrogen (BUN) of those in the CON group, and concentrations of BUN were higher in the RSM group than in the HLB and HLB + RSM group. Compared with the CON group, serum levels of glutamine, glycine, β-glucose were lower and that of choline was higher in the HLB group; serum levels of lactate were lower and that of choline, glutamate were higher in the HLB + RSM group. Compared with the HLB + RSM group, serum levels of glycerophosphoryl choline (GPC) and lactate were higher, and those of choline, glutamine, glutamate, leucine, N-acetyaspartate, α-glucose, and β-glucose were lower in the HLB group; serum levels of citrate, GPC and lactate were higher, and those of 3-Hydroxybutyrate, betaine, choline, glutamate, glutamine, N-acetylglycoprotein, N-acetyaspartate, α-glucose, and β-glucose were lower in the RSM group. It could be concluded that concentrate supplementations significantly improved the growth performance of growing yaks and supplementation with HBL or HLB plus RSM was better than RSM during the cold season. Supplementation with HBL or HLB plus RSM affected the serum metabolites of grazing yaks, and both treatments promoted lipid synthesis. Supplementation of yaks with HBL plus RSM could improve energy-supply efficiency, protein and lipid deposition compared with HLB and RSM.

Transcriptomic and Metabolomic Analyses Reveal Inhibition of Hepatic Adipogenesis and Fat Catabolism in Yak for Adaptation to Forage Shortage During Cold Season

“…With the extension of the cold season, the content of CP and EE in herbage decreased, and that of PDF and ADF increased in a previous study ( Saul et al, 2009 ; Zhou et al, 2020 ), which is consistent with our research results. In this present, compared within a warm season, the content of DM and ADF increased in the cold season, whereas the content of CP and EE in herbage decreased.…”

“…Glutathione is a tripeptide that plays a pivotal role in reducing oxidative stress, maintaining redox balance, enhancing metabolic detoxification, and regulating immune system function ( Minich and Brown, 2019 ). PC, a glycerophospholipid and principal component of the VLDL monolayer, is the major phospholipid component of all plasma lipoprotein classes ( Cole et al, 2012 ), which may help in lipid transport and metabolism and boost VLDL synthesis in the liver of yak ( Zhou et al, 2020 ), indicating that a decrease in the levels of circulating VLDLs and HDLs ( Cole et al, 2012 ; Mcfadden, 2020 ) was in agreement with the low levels of LDL and HDL in the serum; these results implied free fatty acids as triglyceride for tissues as energy source storage for utilization ( Hocquette et al, 1998 ). Of note, we also observed a significant decrease in metabolites involved in glutathione metabolism, implying that the shortage of forage may increase yak exercise and physical activity, thereby inducing oxidative stress.…”

Dietary Concentrate Supplementation Alters Serum Metabolic Profiles Related to Energy and Amino Acid Metabolism in Grazing Simmental Heifers

“…For example, Leal et al ( 15 ) found that dairy Holstein calves fed different pre-weaning nutrient diets influenced protein and energy metabolism. A recent study suggested that supplementation with highland barley is involved in regulating the metabolism of several lipid-related metabolites ( 16 ). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been widely used for the identification of biomarkers and metabolism pathway characterization in cows due to its high resolution, detection sensitivity and non-derivatization of samples ( 17 ).…”

Prevalence of Cryptosporidium spp. in Yaks (Bos grunniens) in China: A Systematic Review and Meta-Analysis

“…The forage becomes enriched after the end of cold weather. The body weight and resistance of yaks will increase in the warm weather ( Zhou et al., 2020 ). This may be the reason for the lowest prevalence of Cryptosporidium spp.…”