Relationships between the Concentration of Igf-1 in Serum in Dairy Cows in Early Lactation on Reproductive Performance and Milk Yield

The quality of the transition period determines the lactation of dairy cows and its profitability. In early lactation over 90% of the dairy cows are in a negative energy balance (NEB). NEB has its peak in the first four weeks postpartum and is associated with major alterations in the growth hormone, insulin-like growth factor (GH-IGF) axis. The catabolic situation leads to GH resistance of the hepatic tissue because the liver GH receptors are down regulated in dairy cows. The early lactation period in dairy cattle is characterized by elevated blood GH concentrations while insulin is down regulated. A low IGF-1 concentration in serum is the consequence of this metabolic situation. Another result of this metabolic situation is the induction of gluconeogenesis and ketogenesis in the liver. The cause of low fertility in dairy cows is multifactorial. The objective of our study was to describe concentrations of IGF-1 in serum in the postpartum period of multiparous, high yielding, dairy cattle. We evaluated the effect of the concentration of IGF-1 in serum on reproductive performance.