Effect of Different Times Postpartum on Lipid Metabolism Markers in Adipose Tissue of Holstein Cows

Our objective was to determine the changes in expression of genes related to lipid metabolism in adipose tissue at 20 and 42 d in milk (DIM) in Holstein cows.  Cows (n= 16) were randomly selected and fed the same total mixed ration (TMR) from calving date to 50 DIM. Subcutaneous adipose tissue (AT) biopsies were collected from the tail-head region at 20 and 42 d relative to calving (d 0) as previously described by Sumner and McNamara (2007). The samples were immediately frozen in liquid nitrogen and then transferred to a − 80 °C freezer until analysis. Real-time PCR was conducted in an ABI Prism 7300 instrument (Rotor gene 3000, Corbett Life Science, Concorde, NSW, Australia) and used to measure gene expression related to beta-oxidation (ACOX1= acylcoenzyme A oxidase, CPT1A= carnitine palmitoyltransferase 1A), lipogenesis (SREBP1C= sterol regulatory element binding protein, LPL = lipoprotein lipase) and, lipolysis (ATGL= adipose triglyceride lipase, LIPE = hormone-sensitive lipase) by Real-time PCR. Results showed that genes that have role in the control offatty acid oxidation (CPT1A, ACOX1) were affected by time and enhances with increasing days in milk (P< 0.05). Among those genes significantly increasing in expression were those controlling lipolysis, including ATGL (52%) and LIPE (23%). Genes coding for enzymes controlling lipogenesis significantly decreased, including SREBP1C (−25%) and LPL (−48.4%). Lipid metabolism biomarkers in adipose tissue of Holstein cows affected by different time postpartum.