Genetic parameters estimation of fatty acid and related traits in the longissimus Thoracis of Hu sheep

The influence of fatty acids (FAs) on meat quality and health is widely recognized. However, estimates of genetic parameters for FAs in sheep muscle remain scarce. Here, data from 1230 Hu sheep with integrated pedigree information were used to estimate heritability, genetic correlations, and selection response for FA traits in Longissimus thoracis (LT). A total of 44 individual FAs and 33 FA classes were identified. Among the FAs, 12 (C18:2n6t to C18:3n6), 25 (C18:0iso to C16:0), and 7 (C14:0 to C6:0) had low (0.04–0.15), moderate (0.16–0.29), and high (0.35–0.70) heritability, respectively. Indices of FA metabolism also showed high heritability (0.28–0.44). Estimates of heritability for saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids decreased with increase in FA unsaturation. Positive genetic and Spearman correlations were observed among most FAs, particularly among C10 ∼ C18 FAs. The unsaturation index (UI), health-promoting index (HPI), and hypocholesterolemic/hypercholesterolemic ratio (h/H) had strong and negative genetic correlation with SFA, MUFA, unsaturated fatty acids (UFA), and intramuscular fat (IMF). Selecting for improved HPI, UI, and h/H, resulted in a favorable response in several traits including UFA/SFA, PUFA/SFA, MUFA/SFA, thrombogenic index (TI), atherogenic index (AI), SFA, C12:0, C16:0, and C18:0. These findings can be used to formulate breeding strategies to improve the FA profiles of LT in Hu sheep.