Continuous lactation in dairy cows: effects on feed intake, milk production, and mammary nutrient extraction

The effect of the pre-partum dry period was investigated in two groups of cows, either dried-off 7 weeks pre-partum or milked continuously into the next lactation, omitting the dry period. Continuous lactation decreased milk yield in the following lactation by appr. 24%. This was associated with a lower mammary capacity for nutrient uptake and extraction. Continuously milked cows were less metabolically stressed in the periparturient period, probably due to lower milk production. This partly explains the observed elevated milk protein content in these cows. The magnitude of change considered, local regulatory mechanisms must have been affected as well.