The changes in growth performance and lipid metabolism of pigs with yellow fat induced by high dietary fish oil

Abstract

Abstract: The aim of this study was to investigate the alteration in growth performance and lipid metabolism during the development of yellow fat in pigs. A total of 30 pigs (9.23 ± 0.21 kg) were assigned to three treatments: (1) low fish oil (LFO), basal diet + 2% fresh fish oil; (2) high fish oil (HFO), basal diet + 8% fresh fish oil; and (3) oxidized fish oil (OFO), basal diet + 8% OFO (peroxide value = 250 meqO2 kg-1). Pigs fed HFO and OFO diets showed yellow staining of fat and decreased growth performance, including average daily gain, average daily feed intake, and final body weight (P < 0.01). The oxidized lipid markers malondialdehyde, yellowness b* of backfat, perirenal fat, and abdominal fat were markedly increased in the pigs fed with HFO and OFO (P < 0.05). Furthermore, following HFO feeding, pigs showed significant decreases in n-6 polyunsaturated fatty acid, n-6/n-3 polyunsaturated fatty acid ratio and mRNA expression levels of CCAAT-/enhancer-binding protein alpha, fatty acid synthase, lipoprotein lipase, and hormone-sensitive lipase in backfat (P < 0.01). Overall, pigs with yellow-fat trait showed decreased growth performance and altered lipid metabolism by the high fish oil feeding.