Comparative Analysis of Fatty Acid Composition in Skeletal Muscles and Serum of Tianfu Goats

Fatty acid composition contributes to the nutritional characteristics of goat meat, but its variation among anatomical muscles remains insufficiently characterized. This exploratory study determined fatty acid profiles in six skeletal muscles and serum from nine 10-month-old castrated male Tianfu goats raised under a common farm feeding and management regimen using targeted gas chromatography–tandem mass spectrometry (GC–MS/MS). Oil Red O staining was also performed for semiquantitative histological analysis of the six skeletal muscles. Thirty-four fatty acids were detected in skeletal muscle, with oleic acid (C18:1n9c), palmitic acid (C16:0), stearic acid (C18:0), and linoleic acid (C18:2n6c) as the predominant components. Monounsaturated fatty acids (MUFAs) constituted the largest fatty acid subclass in skeletal muscle, whereas saturated fatty acids (SFAs) predominated in serum. The longissimus dorsi (LD) and supraspinatus (SS) showed relatively stronger Oil Red O-positive staining. The total fatty acid concentration was significantly higher in SS than in the semimembranosus (SM) muscle (18,282.09 ± 8516.92 vs. 5831.66 ± 3310.31 μg/g, p < 0.05). SS also contained higher concentrations of polyunsaturated fatty acids (PUFAs), SFAs, and MUFAs than SM (1065.99 ± 425.52 vs. 421.00 ± 103.96, 6973.64 ± 3325.02 vs. 2374.02 ± 1383.12, and 10,242.46 ± 4812.55 vs. 3036.65 ± 1841.48 μg/g, respectively; p < 0.05). Twenty-seven fatty acids were shared between serum and skeletal muscle, and correlation analysis with false discovery rate (FDR) correction revealed exploratory muscle-specific serum–muscle association patterns. Overall, Tianfu goat skeletal muscles exhibited a shared MUFA-dominant profile but clear anatomical variation in fatty acid abundance, with SS and LD showing potential for nutritional differentiation and value-added utilization.