title: The effect of excess cobalt on milk fatty acid profiles and transcriptional regulation of SCD, FASN, DGAT1 and DGAT2 in the mammary gland of lactating dairy cows.
abstract: The main objective of this study was to investigate the effect of excess cobalt (Co) on gene expression of stearoyl-CoA desaturase (SCD), fatty acid synthase (FASN), diacylglycerol acyltransferase 1 (DGAT1) and diacylglycerol acyltransferase 2 (DGAT2) of lactating dairy cows in relation to milk fatty acid profile. Seven multiparous cows of the Norwegian Red cattle breed (NRF) had their basal diet supplemented with 1.4 g Co as a 24 g/l solution of Co-acetate per os twice daily for 7 days followed by a 9-day depuration period. Udder biopsies were performed prior to the treatment period, after 1 week of treatment and immediately after the depuration period. Excess Co reduced the proportion of all cis-9 monounsaturated fatty acids and increased the proportion of 18:0 in milk. However, gene expression levels of SCD, DGAT1, DGAT2 and FASN were not significantly altered. Our results indicate that the effect of Co on milk fatty acid profile is mediated at the post-transcriptional level by reduced activity of SCD in the mammary gland. Potential mechanisms explaining how Co might reduce stearoyl-CoA desaturation are discussed.
authors: Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway. inger.johanne.karlengen@umb.no
authors: I J
authors: IJ
authors: Karlengen
authors: O M
authors: OM
authors: Harstad
authors: O
authors: O
authors: Taugbøl
authors: I
authors: I
authors: Berget
authors: A H
authors: AH
authors: Aastveit
authors: D I
authors: DI
authors: Våge
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002417:Cattle; D003035:Cobalt / Q000008:administration & dosage / Q000009:adverse effects*; D051048:Diacylglycerol O-Acyltransferase / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000201:enzymology; D008892:Milk / Q000737:chemistry*; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D003035:Cobalt; D013230:Stearoyl-CoA Desaturase; D051048:Diacylglycerol O-Acyltransferase; D064429:Fatty Acid Synthases