Future proofing NZ dairy cows

AgResearch scientists have unlocked the first keys for improving NZ's dairy cows' milk production. One and a half years into their research on how the mammary gland is able to respond to different environmental influences, they have now identified, what they term, an "epigenetic event". The Dairy Scientist leading this project is Dr Kuljeet Singh, who says it is well known that factors such as nutrition and hormones influence the number and activity of the cells within the mammary gland that secrete milk proteins, therefore influencing levels of milk production. With a lot still to be discovered about how the secretory cells respond to these external and internal influences, Dr Singh and her team's studies suggest the potential of epigenetic regulation to manipulate mammary function. The term epigenetics refers to changes in phenotype or gene expression caused by chemical changes to the DNA, rather than changes in the DNA sequence itself. Most epigenetic changes only occur within the course of one individual organism's lifetime, but some epigenetic changes are inherited from one generation to the next. "Consequently, our research will lead to novel approaches, such as nutritional interventions for manipulating epigenetic mechanisms. Not only will that enhance the lifetime lactation performance of dairy cows, but may also enhance the lactation performance of their calves," she says. Dr Singh says recent research also highlights critical mammary cell signalling or biochemical pathways that play an important role in the regulation of milk production. This leads to the possibility of developing novel intervention technologies, such as using supplements or agonists (drugs that bind to a receptor of a cell and trigger a response by the cell) to modulate specific signalling pathways to enhance the efficiency of milk production in dairy cows.