How is a dairy's RHA calculated?

The correct approach to calculating a dairy's RHA, or Rolling Herd Average, involves determining the total amount of milk produced over the past year relative to the total number of cow years within that period. Specifically, this calculation entails dividing the total milk output from the last 365 days by the total number of cow years—effectively accounting for each cow's contribution to the herd's overall production.

This method accurately reflects both the quantity produced and the labor factor involved in dairy farming, providing a clearer picture of the herd's productivity. Cow years take into account the number of cows and how long they have been part of the herd, which ensures that the calculation represents a true average of production over the entire herd, inclusive of pregnancies and other factors that may affect individual cow productivity.

Other methods, such as averaging individual cow outputs or dividing total milk by the number of dairy farms, do not provide a comprehensive view of herd performance as they either fail to consider the total production from multiple cows or do not account for the variability and management of each farm. Thus, RHA calculations based on cow years provide a more precise metric for evaluating and comparing dairy herd productivity.