Association of KIRREL3 Intronic Polymorphisms with Carcass Traits, Meat Quality, and Muscle Fatty Acid Composition in Woking Cattle

Abstract

Simple Summary This study examined whether two SNPs in the KIRREL3 gene are associated with meat quality in Woking cattle, a high-quality beef breed developed in Jilin Province, China (n = 473, plus an independent validation cohort of n = 41). At the 63-bp site (g.29756010C>T), TT animals showed higher dressing percentage, rib thickness, and meat grade than CC animals at both 36 and 48 months of age, and higher intermuscular fat thickness at 36 months. In the validation group, CC animals had higher intramuscular fat content and muscle KIRREL3 mRNA levels than TT, yet received lower meat grades. Five fatty acids differed significantly among genotypes after Benjamini–Hochberg correction (q < 0.05), including cis-10-pentadecenoic acid (C15:1), γ-linolenic acid (C18:3n6), and nervonic acid (C24:1); the dominant fatty acids (C16:0, C18:1n9c, C18:0, C18:2n6c) showed no significant differences. Together, these results identify the 63-bp site as a candidate marker for early marker-assisted selection to improve meat quality in Woking cattle, pending confirmation in larger cohorts and functional studies.