| Abstract: | The fatty acid composition of the abomasum and rumen tissues of 16-week old and 80-week old Romney ewes fed on pasture has been determined. For 16-week old lambs it was comparable to that of the longissimus dorsi of 26-week old lambs. At 80 weeks the rumen lipids showed a highly significant decrease in total saturated fatty acids, myristic acid and lower saturated acids with a corresponding increase in total unsaturated and octadecenoic (oleic) acids. The abomasum lipids showed similar changes. The reduced contents of myristic, lauric and decanoic acids in the lipids of the older animals were consistent with the removal of these acids from the diet. Whereas before weaning the dietary fetty acids are rich in myristic, lauric and decanoic acids, the fatty acids of sheep at pasture comprise mainly linotenic and palmitic acids. Consideration of the results of other investigations suggests that the changes in the fatty acid composition of the lipids of grazing sheep with age observed for the rumen and abomasum tissues may apply to muscle and fatty tissues generally. |
