Lipidomics and Transcriptome Reveal the Effects of Feeding Systems on Fatty Acids in Yak's Meat

The differences of fatty acids in yak's meat under graze feeding (GF) and stall feeding (SF) regimes and the regulation mechanism of the feeding system on the fatty acids content in yak 's meat was explored in this study. First, the fatty acids in yak's longissimus dorsi (LD) muscle were detected by gas liquid chromatography (GLC). Compared with GF yaks, the absolute content of sigma SFAs, sigma MUFAs, sigma UFAs, sigma PUFAs and sigma n-6PUFAs in SF yak's LD were higher, whereas sigma n-3PUFAs was lower; the relative content of sigma MUFAs, sigma PUFAs, sigma n-3PUFAs and sigma UFAs in SF yak's LD were lower, whereas sigma SFAs was higher. The GF yak's meat is healthier for consumers. Further, the transcriptomic and lipidomics profiles in yak's LD were detected by mRNA-Sequencing (mRNA-Seq) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), respectively. The integrated transcriptomic and lipidomics analysis showed the differences in fatty acids were caused by the metabolism of fatty acids, amino acids, carbohydrates and phospholipids, and were mainly regulated by the FASN, FABP3, PLIN1, SLC16A13, FASD6 and SCD genes in the PPAR signaling pathway. Moreover, the SCD gene was the candidate gene for the high content of sigma MUFA, and FADS6 was the candidate gene for the high content of sigma n-3PUFAs and the healthier ratio of sigma n-6/sigma n-3PUFAs in yak meat. This study provides a guidance to consumers in the choice of yak's meat, and also established a theoretical basis for improving yak's meat quality.

Automated summary

This study investigated the differences in fatty acids in yak's meat under graze feeding and stall feeding, suggesting that grazed yak's meat is healthier for consumers. Transcriptomic and lipidomics analysis identified key genes regulating fatty acid content in yak meat.