Phospholipid data from the Longissimus dorsi (eye muscle) and M. brachii (shoulder muscle) of Jersey and Limousin cattle were used to study the effects of genotype, anatomical site and their interactions on fatty acid composition. Results indicated that phospholipids of the two muscles did not differ in total saturated, monounsaturated and polyunsaturated fatty acids. However, they differed in specific fatty acids 18:0 and 22:5. Genotype was a significant source of variation for the
individual fatty acids 18:2 and 18-di-methyl-aldehyde (18-DMA). Significant genotype by anatomical site interactions were observed in the levels of 18-DMA, 18:0, 18:2 and 20:5 fatty acids. It was concluded that the fatty acid composition of phospholipids from biopsy samples of the L.
dorsi and M. brachii muscles were similar, but there were significant differences in some individual fatty acids. Furthermore, attention should be paid to genotype by anatomical site interactions that can exist in some individual fatty acids
