Selim S, Salin S, Taponen J, Vanhatalo A, Kokkonen T, Elo K T
Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland; and.
Physiol Genomics. 2014 May 1;46(9):328-37. doi: 10.1152/physiolgenomics.00115.2013. Epub 2014 Feb 25.
Overfeeding during the dry period may predispose cows to increased insulin resistance (IR) with enhanced postpartum lipolysis. We studied gene expression in the liver and subcutaneous adipose tissue (SAT) of 16 Finnish Ayrshire dairy cows fed either a controlled energy diet [Con, 99 MJ/day metabolizable energy (ME)] during the last 6 wk of the dry period or high-energy diet (High, 141 MJ/day ME) for the first 3 wk and then gradually decreasing energy allowance during 3 wk to 99 MJ/day ME before the expected parturition. Tissue biopsies were collected at -10, 1, and 9 days, and blood samples at -10, 1, and 7 days relative to parturition. Overfed cows had greater dry matter, crude protein, and ME intakes and ME balance before parturition. Daily milk yield, live weight, and body condition score were not different between treatments. The High cows tended to have greater plasma insulin and lower glucagon/insulin ratio compared with Con cows. No differences in circulating glucose, glucagon, nonesterified fatty acids and β-hydroxybutyrate concentrations, and hepatic triglyceride contents were observed between treatments. Overfeeding compared with Con resulted in lower CPT1A and PCK1 and a tendency for lower G6PC and PC expression in the liver. The High group tended to have lower RETN expression in SAT than Con. No other effects of overfeeding on the expression of genes related to IR in SAT were observed. In conclusion, overfeeding energy prepartum may have compromised hepatic gluconeogenic capacity and slightly affected IR in SAT based on gene expression.
干奶期过度饲喂可能使奶牛易患胰岛素抵抗(IR)增加,并增强产后脂肪分解。我们研究了16头芬兰艾尔夏奶牛肝脏和皮下脂肪组织(SAT)中的基因表达,这些奶牛在干奶期的最后6周要么饲喂对照能量日粮[Con,99 MJ/天代谢能(ME)],要么在最初3周饲喂高能日粮(High,141 MJ/天ME),然后在预期分娩前3周将能量供应量逐渐降至99 MJ/天ME。在相对于分娩的-10、1和9天采集组织活检样本,在-10、1和7天采集血样。过度饲喂的奶牛在分娩前干物质、粗蛋白和ME摄入量以及ME平衡更高。各处理间日产奶量、活重和体况评分无差异。与Con组奶牛相比,High组奶牛血浆胰岛素往往更高,胰高血糖素/胰岛素比值更低。各处理间循环葡萄糖、胰高血糖素、非酯化脂肪酸和β-羟基丁酸浓度以及肝脏甘油三酯含量无差异。与Con组相比,过度饲喂导致肝脏中CPT1A和PCK1降低,G6PC和PC表达有降低趋势。High组SAT中RETN表达往往低于Con组。未观察到过度饲喂对SAT中与IR相关基因表达的其他影响。总之,基于基因表达,产前能量过度饲喂可能损害了肝脏糖异生能力,并对SAT中的IR产生了轻微影响。