The great debate - is once or twice a day milking best?

Sometimes, in response to seasonal factors such as a drought or extremely wet conditions, some dairy farmers will often make the strategic decision to switch to once-a-day milking. For whatever reason it’s become a hot topic this year and some farmers are switching full time. Full season or strategic, once-a-day has both pros and cons.


  • Frees up labour
  • Reduces stress on staff
  • Gives managers more time to plan and manage
  • Takes pressure off cows
  • Lowers farm running costs
  • Helps cows reach body condition score (BCS) targets during dry summer periods
  • Sets the farm up to maximise days in milk from autumn pasture growth
  • Can also help extend the grazing rotation
  • Done early and with enough feed, it can increase cow body condition score gain through autumn and therefore extend lactation


Actually, there hasn’t been a lot of research done so most of what we have to go on is anecdotal or from analysing data.

At a DairyNZ seminar in Gore earlier this year, one of their scientists, Paul Edwards, shared some insights he’d gathered from looking at data from the Dairy Industry Good Animal Database. Overall he found results were quite unique from farm to farm, but there were some potential trends:

  • Just over 50% of herds are full season twice-a-day
  • Some are a mix of once and twice-a-day
  • Around 20% switch between the two during the season
  • Compared to twice a day, once-a-day production decreased 11% on average in the first season. By year four, production was back up to where it started before the switch, but was still 11% behind twice-a-day pairs taking economic implications into consideration.
  • Cows producing less than 300kg/ms tended to improve when switched to once-a-day
  • Cows producing more than 300kg/ms tended to drop off when switched to once-a-day
  • Once-a-day farms retain profit parity with twice-a-day due to reduced costs
  • Once-a-day cows tended to have a tighter calving spread
  • Replacement rates were about the same
  • Once-a-day farmers culled fewer empties (more due to lower production and udder related reasons)

This information was published on the New Zealand Herald website in April. Read the full article here


  • Monitoring feed when switching
  • Your first year will be the hardest as you establish a new system
  • Breeding and genetics plays a huge role in getting it right
  • Doesn’t suit all farms
  • Takes a lot of planning


Before changing your farm system it’s important to assess what’s right for you. Here’s a list of the reasons and things you might want to consider if you’re thinking of switching:

  • Want a better work/life balance, or finding milking physically challenging.
  • Need more time for other farm tasks.
  • Find it difficult to attract/retain suitable staff.
  • TAD is putting pressure on current resources.
  • No capital to invest in upgrading tired infrastructure but it’s still good enough for OAD.
  • Herd has to do a lot of walking.
  • There are significant differences in altitude on your farm.
  • Have a 6 week in-calf rate of less than 78%.
  • Your business could sustain at least one season of reduced milksolids production per cow (e.g. 10-20%)
  • Current SCC is low
  • Have a high BW herd

We reckon it’s a tie in the great debate over which is better, once or twice a day milking. It all depends on what’s right for you, your herd and farm. If you are considering the switch, see what you can learn from this North Island farmer who’s been milking once a day for around 6 years.