AUTHOR=Bao Gaoliang , Liu Xiu , Wang Jiqing , Hu Jiang , Shi Bingang , Li Shaobin , Luo Yuzhu 

TITLE=Effects of Slaughter Age on Myosin Heavy Chain Isoforms, Muscle Fibers, Fatty Acids, and Meat Quality in Longissimus Thoracis Muscle of Tibetan Sheep

JOURNAL=Frontiers in Veterinary Science

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.689589

DOI=10.3389/fvets.2021.689589

ISSN=2297-1769

ABSTRACT=This study investigated the effect of slaughter age on meat quality, fatty acid profile, and expression of myosin heavy chain (MyHC) isoform genes in Tibetan sheep. A total of 24 Tibetan sheep including 4-months-old (4 m), 1.5-years-old (1.5 y), 3.5-years-old (3.5 y), and 6-years-old (6 y) were randomly selected. The results indicated that the MyHC Ⅱx and MyHC Ⅱb mRNAs increased with age, whereas MyHC Ⅱa mRNA decreased. MyHC Ⅰ mRNA was highest at 3.5-years-old (3.5 y). Intramuscular fat (IMF) was highest at 1.5-years-old (1.5 y), the pH45min and pH24h value of 6-years-old (6 y) sheep were lower than the other groups, shear force of the meat increased with age (P<0.05), and drip loss increased with age (P<0.01). Tibetan sheep at 1.5 y had the lowest saturated fatty acid (SFA) contents and highest mono unsaturated fatty acid (MUFA) contents (P<0.05). These results demonstrate the effect of age on meat quality of Tibetan sheep through regulation of expression of the MyHC isoforms which changed the myofiber types, and 1.5-years-old Tibetan sheep meat was more suitable for a healthy human diet.