Once-a-day milking

Once-a-day milking could reduce total production and emissions but maintain profitability, if reduced input costs balance the reduction in total milk production.

How it works

Making a deliberate decision to milk only once a day (OAD) throughout lactation can, under the right circumstances, reduce emissions and maintain profitability.

rangiora DSC1519 credit dave allen NIWA

The main effect of permanent OAD is a reduction in daily milk yield per cow, resulting in reduced feed demand by cows and hence reduced emissions. The economic impact of reduced production is compensated by reduced input costs, particularly labour. The effect on profitability depends strongly on pay-outs for milk solids and reductions in labour costs. In addition, the effect on production, emissions and profitability is likely to change over time, as farms adapt to OAD and adjust the genetic make-up of their herd.

How will this affect my GHG number?

Modelling indicates that this approach (with the qualifications noted above) could reduce emissions by 6–7%. However, how OAD is implemented will influence this. For example, if more cows are kept to compensate for the reduced milk yield per cow, then reductions in emissions may not eventuate. It's critical to start by finding out what your on-farm greenhouse gas emissions are.


A big risk from an emissions perspective is that any reductions in emissions are short-lived. Selection for cows suited to OAD may mean that, over time, OAD cows increase their feed demand and return to their previous productivity levels. If cow numbers are increased to compensate for decreased individual cow production this could mean that, over time, emissions actually increase. From a profit perspective, decreased milk revenues must be matched by cost savings; this will be more difficult when milk pay-outs are high.

More information

For more information on once-a-day milking, see: