Effect of Pasture and Lipid Supplementation on Production Performance, Carcass Quality, Fatty Acid Composition and Lipid Metabolism of Lamb

Abstract

The significance of diet during the growing and finishing of lambs on production and lipid metabolism was studied. Thirty-two intact 5-6 month old Suffolk cross ram lambs that had previously grazed either red clover (RC) or tall fescue (TF) were finished on a concentrate diet containing isolipidic supplements of either fish oil (FO), soybean oil (SBO) or a 30:70 mixture of CLA isomers and SBO (CLA+). When compared to TF, RC increased carcass weight (1.1-fold) and content of muscle ALA, subcutaneous adipose ALA and total PUFA (1.2-fold), and decreased D9D expression in liver (1.6-fold). FO decreased carcass weight (1.1-fold) and increased muscle and subcutaneous adipose EPA (5.6- and 10.8-fold), DHA (5.8- and 13-fold) and total PUFA (1.4- and 1.2-fold) while decreasing SREBP (1.6-fold) expression in liver and SPOT14 and leptin expression in enteric adipose. CLA+ increased subcutaneous adipose CLA isomers (1.8-fold) with no effect on carcass weight or gene expression.