PhD defence

More milking days with lower yields. Sustainability impacts of short or no dry periods in dairy cows


Farmers traditionally stop milking a cow 2 months before her next calving. This ‘dry period’ maximises milk production in the next lactation, but the high metabolic load can reduce health in early lactation. Short (about 1 month) and no dry periods can improve the metabolic status in early lactation, but reduce milk production. This research evaluated impacts of short and no dry periods on aspects of cow welfare, cash flows at farm level, and greenhouse gas emissions. Cow behaviour suggested that welfare of cows with no dry period was not impaired by milking in late gestation. Short and no dry periods had a negative impact on cash flows (-€12 and -€16 per cow per year) and greenhouse gas emissions per unit milk (+0.8% and +0.5%) based on a model assessment. However, these small negative are likely to be offset by a reduced disease incidence and increased lifespan. Based on this study, therefore, short and no dry periods seem sustainable solutions to improve the metabolic status of dairy cows in early lactation.