Metabolic status, lactation persistency, and udder health of dairy cows after different dry period lengths

Cows traditionally have a 6 to 8 week non-lactating –‘dry period’- before calving and the start of the next lactation in order to maximize milk production in the subsequent lactation. An omitted, compared with a shortened, dry period reduces milk yield and improves energy availability in cows postpartum, but effects on udder health and persistency were unclear. Cows without a dry period fattened and spontaneously dried off due to the improved energy availability. Reducing the energy availability in the feed for cows without a dry period did not affect fattening or lactation persistency in late lactation. Cows with a short or without a dry period did not receive dry cow antibiotics in this study and this did not affect udder health across the dry period or in early lactation, but seemed to impair udder health in late lactation for cows without a dry period.