Consequences of Lactation Length Management for Health and Fertility in Dairy Cows

Extending lactation length, as well as shortening or omitting the dry period have interesting perspectives on health and fertility of high-producing dairy cows. By extending lactation length, the frequency of critical calving events for the cow reduces, herewith reducing the frequency of periods with increased risk for health problems. Alternatively, shortening or omitting the dry period reduces the number and magnitude of peripartum transitions for the cow, with less milk and a better energy balance after calving. Potential risks of these management strategies are that milk yield of cows at the end of lactation is too low to extend the lactation period, and that cows fatten in late lactation. Therefore, both extending lactation length and shortening or omitting of the dry period might not fit every cow. Individual cow characteristics like parity, milk yield level, body condition, or health status contribute to the response of the cow to an extended lactation or shortened or omitted dry period. These individual cow characteristics can be used in customized management strategies to optimize lactation length or dry period length for individual cows. Customized lactation or dry period length could limit the impact at herd level of disadvantages concerning milk losses and body fattening and maintain benefits for improved cow health and fertility, reduced number of surplus calves, and increased work satisfaction for the farmer.