Effects of rumen-protected, long chain fatty acid, calcium salt supplementation on total lipid, fatty acids, and related gene expression in Korean cattle

Abstract

Rumen-protected linoleic acid-enriched calcium salts (LAE-Ca salts) and oleic acid-enriched calcium salts (OAE-Ca salts) were examined for their effects on total lipids, fatty acids, and lipid metabolism gene expression in Korean steers. A total of 30 animals with a mean body weight of 597 ± 5 kg were divided into three treatment groups: Control, control diet without additional fat (n = 10); LAE-Ca salts fed 50% LAE-Ca salts (n = 10); and OAE-Ca salts, fed 50% OAE-Ca salts (n = 10); 100 g/d/animal on dry matter required basis (DMR). Results revealed that lipid content was substantially lower in the OAE-Ca salts group. Total poly-unsaturated fatty acid (PUFA), ω6, and ω3 were substantially higher in the OAE-Ca salts group but the percentage of saturated fatty acids (SAF), mono-unsaturated fatty acids (MUFA), and unsaturated fatty acids (USFA) was not affected. Up-regulation of leptin gene expression was observed in the LAE-Ca salts group. The mRNA levels of genes related to lipogenesis, including lipoprotein lipase (LPL), fatty acid synthase (FAS), and stearoyl-CoA desaturase (SCD), were not statistically different between groups. However, acetyl CoA carboxylase (ACC), lipolytic adipose triglyceride lipase (ATGL), and fatty acid binding protein (FABP4) were substantially higher in the LAE-Ca salt group; hormone-sensitive lipase (HSL) was higher in the OAE-Ca salt group. Therefore, our findings indicate that fatty acid-enriched calcium salt diets affect total lipids, fatty acids, and the expression of certain lipid metabolism genes in Korean cattle.