High-Energy Diet at Antepartum Decreases Insulin Receptor Gene Expression in Adipose Tissue of Postpartum Dairy Cows

The objective of the study was to determine expression of gene of insulin receptor (INSR) in adipose tissue of postpartum dairy cows fed diets containing different amounts of energy at the antepartum period. Healthy pregnant dairy cows (n=45) on 21^st d of the antepartum were divided into three groups differing in diet composition, namely: control group fed a normal diet, high energy group fed a high energy diet, and low energy group fed a low energy diet. Twenty-one days after parturition, INSR gene expression in adipose tissue was determined by internally controlled reverse transcriptase PCR. The level of INSR mRNA in adipose tissues of cows fed the high energy diet was substantially lower than that in cows fed normal or low energy diets. A relatively higher level of INSR mRNA in the adipose tissue of cows fed low energy diet may be beneficial for gluconeogenesis and lipogenesis, which can relieve an energy negative balance. Reduced level of INSR mRNA in adipose tissue of cows fed high energy diet indicates that the response to insulin has significantly decreased.