The liver is the principle site of production of both insulin-like growth factor (IGF) and the associated binding proteins (IGFBPs). During lactation, tissue reserves are mobilised and gluconeogenesis in the liver is up-regulated. The high nutrient demands of lactogenesis result in a physiological state of negative energy balance (EB), a situation that has profound effects on the IGF system. It is also known that the IGF family members play an important role in fertility by acting on reproductive tissues. Genetic selection of dairy cows for high yield milk production has led to a decline in fertility and it is thus hypothesised that this disruption is a consequence of down-regulation of certain IGFs and/or their receptors and binding proteins. In this study a qPCR approach was used to quantify the expression levels of specific transcripts of the IGF family in the liver during different situations of mild or severe energy balance.