Changing milking intervals is one way to reduce work hours and/or increase flexibility to improve workplace attractiveness.
The difference between frequency and interval
Milking frequency refers to the number of milkings in a day, milking interval refers to the number of hours between milkings.
The three main examples of milking frequency used are TAD (2 milkings per day), 3-in-2 (average of 1.5 milkings per day) and OAD (1 milking per day).
The milking interval determines the frequency. For example, an interval of 24 hours means milking OAD.
However, it also determines the timing of milkings within a milking frequency. For example, 10-14 and 8-16 are both TAD (milking twice-a-day), however using 8-16 means people can start 2 hours later in the morning.
An underlying knowledge of udder physiology enables us to modify milking intervals to suit the people working on-farm.
Research has identified that milk secretion is almost linear up to 16 hours post milking and then declines slightly from 16 to 24 hours.
In theory, this means if the time between milkings is under 16 hours there will be minimal production loss assuming other factors (e.g. feeding) are constant. Further information from once-a-day (OAD) experiments suggest that yield may be decreased further in a second 24 hour period.
Although volume is decreased with extended milking intervals, a higher fat and protein composition helps to offset some of this decrease.
Examples of the practical application of this knowledge include 8-16 milking intervals (milking twice-a-day) or 16-16-16 (milking three times in two days). In combination with other farm system changes, the use of longer milking intervals such as 12-18-18 and OAD are possibilities whilst maintaining profitability. More info can be found on these in the links further down the page.
Research has also identified variation between individual animals and breeds, meaning longer milking intervals are possible for some animals before production declines. This could be a focus of future breeding efforts.
Use of milking intervals
Traditionally, milking twice-a-day (TAD) has been the industry norm, however, recent data suggests only 45 percent of farms now milk TAD all year round.
In the 2019/20 season, over 50 percent of farms nationally were implementing different milking intervals for all, or part of the season. The type of milking intervals adopted differed around the country, with once-a-day (OAD) being more popular in the North Island and 3 milkings in 2 days (3-in-2) seeing greater use in the South Island.
Adjusting milking intervals
For more information about adjusting milking intervals and the opportunities this creates, see the links below.
TAD milking is our most common milking interval nationwide. Find out how you can make TAD more flexible for your farm.
OAD milking is the practice of milking cows only once during a 24 hour period. Find out if OAD is right for your farm.
Flexible milking is a catch-all term given to milking intervals that sit between more traditional once-a-day (OAD) or twice-a-day (TAD) milking.