Fatty acid composition of tissue phospholipids of the foetal calf and neonatal lamb, deer calf and piglet as compared with the cow, sheep, deer and pig

Abstract

1. The fatty acid compositions of muscle and brain phospholipids of foetal calves, neonatal lambs, deer calves and piglets, and mature cattle, sheep, deer and pigs were determined. The cattle, sheep and deer had previously grazed ryegrass–clover pastures, and the pigs had been given rations based on barley. Two steers and four sheep had been given protected polyunsaturated lipid-protein supplements.2. In muscle phospholipids the values for triene:tetraene were 1.5 for neonatal lambs and 0.3 for foetal calves. Levels of linoleic acid were low compared with those in older animals but levels of the fatty acids 22:5ω3 and 22:6ω3 were comparatively high. For arachidonic acid there was little difference between young and mature animals.3. In muscle phospholipids of neonatal piglets and deer calves values for triene:tetraene were low. The piglet also had a low value for 22:5ω3:22:6ω3 compared with those in deer, calves or lambs. This ratio showed a proportionately greater increase with maturity in the pig than in cattle and sheep. Whilst the neonatal deer had higher linoleic acid levels than the other young ruminants, the fatty acid composition of muscle phospholipids of mature deer was rather similar to that in other ruminants.4. Phospholipids of brain showed little difference in fatty acid composition between foetuses or neonates and the mature animals. There was higher 22:4ω6 content in the adult ruminant with even higher levels in sheep given protected polyunsaturated fat. Linoleic acid was barely evident in any animal. The 22:6ω3 content was as high in the foetal or neonatal ruminant brain as in the adult, and higher than in the piglet. The fatty acid composition of brain phospholipids of young deer was similar to that in other ruminants.5. In other tissue phospholipids in foetal or neonatal ruminants and piglets there were high levels of 22:6ω3 in liver and low levels in lung. The neonatal animals, in particular, had high palmitic acid levels in lung. Hearts of young ruminants contained high levels of 20:5ω3 and C₁₆-aldehyde derived from plasmalogens. Piglet heart contained higher linoleic acid and arachidonic acid, possibly due to increased entry of linoleic acid across the placenta from the sow.