Cows at the beginning of lactation often do not meet their energy needs by feeding and therefore mobilize body fat, which produces ketone bodies, including β-hydroxybutyrate (BHB). They are nevertheless usually inseminated around 60 d postpartum, when they are still in this characteristic period of energy deficit. The aim of this study was to observe the effects of negative energy balance on embryo quality and to identify ways to improve the fertility of dairy cows. Holstein cows (n = 18) grouped as high or low BHB based on blood measurement at day 45 postpartum were estrus-synchronized and treated with follicle-stimulating hormone to obtain multiple follicle development, induced to ovulate and inseminated with sexed semen around day 60 postpartum. Of the 290 embryos collected over 16 mo, 159 were of quality I to IV. Based on microarray analysis of gene expression, exposure to an energy deficit metabolic environment (high BHB) during early development appeared to modify signaling by the mTOR and sirtuins pathways in the embryo, implying mitochondrial dysfunction and inhibition of transcription, leading to slower cell division, thus programming the embryo to be more energy efficient. Altered methylation markers suggested that such coping mechanisms might persist into adulthood.

泌乳初期的母牛通常无法通过喂养来满足其能量需求，因此会动员体内脂肪，从而产生包括β-羟基丁酸酯（BHB）在内的酮体。然而，当它们仍处于能量缺乏的典型时期时，通常在产后60 d左右进行授精。这项研究的目的是观察负能量平衡对胚胎质量的影响，并确定提高奶牛育性的方法。在产后第45天根据血样将荷斯坦奶牛（n = 18）分为高或低BHB，进行发情同步并用促卵泡激素治疗以获得多卵泡发育，并在产后60天左右诱导排卵并用有性精液进行授精。在16 mo内收集的290个胚胎中，有159个的质量为I至IV。根据基因表达的微阵列分析，早期发育过程中暴露于能量不足的代谢环境（高BHB）似乎会通过胚胎中的mTOR和sirtuins途径修饰信号传导，暗示线粒体功能障碍和转录抑制，从而导致细胞分裂变慢，因此将胚胎编程为更加节能。甲基化标记的改变提示这种应对机制可能持续到成年期。