LIPIDS IN SUBCUTANEOUS TISSUES AND LONGISSIMUS MUSCLES OF FEEDLOT AND GRASS‐FED EWES1

Abstract

ABSTRACTSubcutaneous and intramuscular lipids from feedlot‐and grass‐fed ewes were studied to determine if diet would influence fatty acid composition of these older animals. Subcutaneous lipid of ewes from the feedlot‐fed group contained more 4‐methyl branched acids, less iso and anteiso branched acids, less stearic acid and more octadecenoic acid than grass‐fed ewes. Only small amounts of medium chain acids (10–15 carbons) were noted in longissimus muscle lipids from both dietary groups and essentially all of them were in the triglycerides. Lipids in longissimus muscle of feedlot ewes contained more monounsaturated and less polyunsaturated acids and this was due to higher levels of triglycerides in longissimus lipid of feedlot‐fed ewes. Approximately three times as much high melting stearic acid was present in subcutaneous lipid of both dietary groups of ewes as has been noted in subcutaneous lipid of lambs. Reduction of high melting stearic acid in mutton fat by a short grain feeding period should make mutton more acceptable.