The effect of feeding system in the expression of genes related with fat metabolism in semitendinous muscle in sheep

The effect of feeding system on the expression of LPL, ACACA, FASN, FABP4, DGAT1, SCD, CPT1B, PRKAA2, LEP, SREBP1, PPARG, PPARA and CEBPB genes in semitendinous muscle was studied. Forty-four single born male lambs of the Rasa Aragonesa breed, allocated to four different dietary treatments, were used: grazing alfalfa, grazing alfalfa with supplement for lambs, indoor lambs with grazing ewes and drylot.Significant differences were found in the expression of genes LPL, ACACA, FASN, FABP4, CPT1B and SCD. Genes related to adipogenesis (LPL, ACACA, FASN, FABP4, and SCD) are up-regulated in the intensive groups. In grazing groups CPT1B gene expression, related to β-oxidation process, is up-regulated. The relative expression of CPT1B was 1.54 fold higher in ALF + S, and 0.43 and 0.37 fold lower in IND- GRE and IND, respectively.The results support the hypothesis that changes in fatty acid profile due to feeding system implicate changes in the mRNA expression level of genes related with fat metabolism. Feeding strategy is an important tool to manipulate intramuscular fatty acid profile in meat through altering gene expression of enzymes related with fat metabolism.