Heat stress affects milk yield, milk quality, and gene expression profiles in mammary cells of Girolando cows

Heat stress is a noted risk factor affecting dairy producers, animal welfare, and food security. Recently, Girolando cows might be encountering increased challenges in maintaining their homeothermy due to a rise in milk production. This study explores the impact of heat stress on physiological parameters, milk yield, milk quality, and mammary cell gene expression in Girolando cows. Results indicate that heat stress causes a decrease in dry matter intake, rumination frequency, and milk yield. It also leads to elevated vaginal temperature, cortisol release, and changes in mammary cell gene expression. However, the heat stress imposed did not affect milk quality.