Sire breed and sex effects on the fatty acid composition and content of heart, kidney, liver, adipose and muscle tissues of purebred and first-cross prime lambs

The present study investigated sire breed and sex effects on the fatty acid (FA) composition and content of subcutaneous adipose, Longissimus lumborum muscle, kidney, heart and liver tissues in prime lambs. Tissue samples were taken from 40 Merino ewe and wether lambs sired by Black Suffolk, Dorset, Merino and White Suffolk rams. FA proportion (% total FA) showed significant variations. The highest relative concentrations of total saturated fatty acid (SFA) were in adipose tissue, concentrations of monounsaturated fatty acids (MUFA) were highest in muscle and concentrations of two nutritionally important omega-3 long-chain (≥C₂₀) polyunsaturated FA (LC-PUFA), namely, eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, were highest in kidney tissue (10.4% total FA), as were those of total PUFA in heart tissue. Sire breed variations in kidney for 18:3n-3, 22:6n-3, 16:0, 16:1n-7c and total omega-6 PUFA, and in muscle for 17:0, 18:3n-3 and 18:1n-7 were evident. Adipose tissue concentrations of 16:1n-9c, 17 : 0 and 16 : 0 in the heart and liver were affected by sire breed. The effect of sex on most major individual FA and totals of SFA, MUFA, omega-3 and omega-6 PUFA were, for the most part, negligible. These results suggest that consumption of lamb heart, liver and kidney can prove beneficial because of their high total PUFA composition and, in particular, concentration (mg/100 g) of key health-benefitting n-3 LC-PUFA. The fact that there were significant sire-breed variations implies that the manipulation of FA composition and content of lamb products and their associated nutritional and sensory qualities will need a deliberate breeding management that matches product goals with available sire breeds.