Comparative Analysis of the Composition of Fatty Acids and Metabolites between Black Tibetan and Chaka Sheep on the Qinghai—Tibet Plateau

Abstract

The objective of this study was to investigate and compare fatty acids and metabolites in the longissimus dorsi muscle between Black Tibetan and Chaka sheep grazing in a highly saline environment. A total of eight castrated sheep (14 months old) with similar body weights (25 ± 2.2 kg) were selected. The experimental treatments included Black Tibetan (BT) and Chaka sheep (CK) groups, and each group had four replications. The experiment lasted for 20 months. All sheep grazed in a highly saline environment for the whole experimental period and had free access to water. The results showed that the diameter (42.23 vs. 51.46 μm), perimeter (131.78 vs. 166.14 μm), and area of muscle fibers (1328.74 vs. 1998.64 μm2) were smaller in Chaka sheep than in Black Tibetan sheep. The ash content in the longissimus dorsi was lower in Chaka sheep than in Black Tibetan sheep (p = 0.010), and the contents of dry matter (DM), ether extract (EE), and crude protein (CP) in the longissimus dorsi showed no differences (p > 0.05). For fatty acids, the proportions of C10:0, C15:0, and tC18:1 in the longissimus dorsi were higher in Chaka sheep than in Black Tibetan sheep (p < 0.05). However, all other individual fatty acids were similar among treatments, including saturated fatty acids (SFAs), unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and the ratios of n-6 PUFAs to n-3 PUFAs and PUFAs to SFAs (p > 0.05). A total of 65 biomarkers were identified between the two breeds of sheep. Among these metabolites, 40 metabolic biomarkers were upregulated in the CK group compared to the BT group, and 25 metabolites were downregulated. The main metabolites include 30 organic acids, 9 amino acids, 5 peptides, 4 amides, 3 adenosines, 2 amines, and other compounds. Based on KEGG analysis, eight pathways, namely, fatty acid biosynthesis, purine metabolism, the biosynthesis of unsaturated fatty acids, renin secretion, the regulation of lipolysis in adipocytes, neuroactive ligand–receptor interaction, the cGMP-PKG signaling pathway, and the cAMP signaling pathway, were identified as significantly different pathways. According to the results on fatty acids and metabolites, upregulated organic acid and fatty acid biosynthesis increased the meat quality of Chaka sheep.

Insights into the effects of saline forage on the meat quality of Tibetan sheep by metabolome and multivariate analysis

“…Pyruvate, as a product of glycolysis and a precursor of the TCA cycle, also undergoes inhibition in its synthesis. Guo ( Guo et al, 2022 ) found the same characteristics in the metabolism of saline and alkaline stress in wheat seedlings.…”

“…Additionally, the n-6/n-3 ratio in the M group was >6, with this value considered as unfavorable for health ( Molendi-Coste, Legry, & Leclercq, 2011 ). Guo et al ( Guo et al, 2022 ). found that up-regulated fatty acids contributed to superior meat quality in Tibetan sheep that are adapted to high-salt environments compared to traditional plateau ones.…”

“…Currently, the Qinghai Province possesses mostly saline-alkali types of grassland, and therefore, in areas such as the Hainan Tibetan Autonomous Prefecture, the Haixi Mongolian-Tibetan-Kazakhstan Autonomous Prefecture or other areas along the Qinghai Lak ( Yang et al, 2023 ), the Tibetan sheep have traditionally been recognized for their superior food and nutritional values. For instance, Guo ( Guo et al, 2022 ) revealed that, compared to traditional grazing, the high-salt environments experienced by Chaka Tibetan sheep increased the fatty acids and metabolic products in the longest muscle on their backs, and this was translated into improved meat quality, with Xu ( Xu et al, 2023 ) further reporting the enhanced texture and flavor of such meat. In addition, K.L.…”

Investigating the Nutritional and Functional Properties of Protaetia brevitarsis Larvae and Isolated Soy Protein Mixtures as Alternative Protein Sources

“…In contrast, the PB:ISP mixture highlights a distinct profile by possibly combining the high protein content of PB larvae with the balanced amino acid and fatty acid profiles provided by ISP, which may offer an advantageous alternative especially in diets restricting traditional meats. Rabbit and goat meats are noted for their healthful fatty acid profiles and lower cholesterol levels, features that are crucial for dietary considerations focused on cardiovascular health [27][28][29]. Our mixture aims to replicate these benefits through a strategic combination of PB and ISP, targeting a profile rich in essential amino acids and healthier fats.…”

Evaluation of the Longissimus Thoracis et Lumborum Muscle Quality of Chaka and Tibetan Sheep and the Analysis of Possible Mechanisms Regulating Meat Quality

“…Chaka sheep originate from Wulan County, Haixi Mongolian and Tibetan Autonomous Prefecture, Qinghai Province. As a semi-fine wool sheep originating from the Qinghai-Tibet Plateau, Chaka sheep is listed as a valuable breed of the Qinghai-Tibet Plateau because of its tender meat, fat but not greasy, fresh but not fatty, and rich in mineral and vitamin characteristics, which received the National Geographical Indication in 2013 [7]. Tibetan sheep is one of the three original sheep breeds in China, and it is native to Tibet, China, though it can also be found in Qinghai, the northwest of Sichuan, and the south of Gansu.…”