Molecular material associated with growth, fertility, and infection risk in dairy calves could serve as indicator of productivity in cows. Key traits in the early development of dairy cattle are influenced by small strands in their genetic material, scientists have found. These short strands, known as micro RNA or miRNA, are involved in regulating gene activity in humans and animals, and have now been shown to regulate tissue growth and production of energy from food in young cows. The research team set out to investigate which genes are involved in cattle growth and infection, to aid understanding of early-life predictors of health and productivity. Early development in dairy cattle is known to impact on later milk production, so understanding calves’ early life performance in terms of growth, infection risk and fertility could serve to predict their longer-term health and productivity. Markers of development Roslin researchers monitored miRNA in blood samples from dairy cattle from birth until the calves first produced milk, a period of three years. Eight miRNAs were found to change as the calves matured, suggesting that some of these are involved in regulating tissue growth and energy use. The findings suggest that miRNA, which is an emerging field of scientific interest, could be used as biological markers of cattle health, the research team says. The study marks the first time miRNA, which has mostly been studied in humans, has been used to measure cattle growth and development. The team hoped to better understand how health and performance of cattle from birth may influence lifetime productivity. These findings open the door to possible large-scale DNA studies to more accurately predict likely health and productivity in dairy cows, and further research could consider the effect of miRNA on milking traits, fertility or risk for specific diseases such as mastitis and lameness. This research was published in PLOS One and supported by a Principal’s Career Development Scholarship at the University of Edinburgh. Issues such as poor health and fertility are a great concern for animal welfare. MiRNA is an emerging field of interest, and there has been a lot of research in a human context. When applied to dairy cows and other cattle, miRNA could become a useful indicator for future health in young cows.Madison MacLeay, PhD student ** The Roslin Institute receives strategic investment funding from the Biotechnology and Biological Sciences Research Council and it is part of the University of Edinburgh’s Royal (Dick) School of Veterinary Studies. **Related linksLink to the original articleScientific publicationImage credit Annie Spratt (Unsplash) Publication date 25 Jul, 2023
