The MaxT strategy is where cows are milked to a pre-determined time based on their milk volume, resulting in less time in the dairy for staff and cows, without affecting milk production or udder health.
There are three steps to implementing MaxT - calculate, implement and monitor.
The first step is to determine your MaxT time. The easiest way to do this is to download DairyNZ’s Milksmart app. By entering the number of litres from the tanker docket, the number of cows going in the vat and your milking start times, the app will calculate the average milk volume per cow for each milking, and the appropriate MaxT time for this volume.
Alternatively, use these tables to calculate your MaxT time manually.
Note: Farmers implementing MaxT for the first time have found it easier to start with using the morning MaxT time and monitoring at cups off as per Step 3.
Alternative calculation to simplify implementation is possible for some herds
The method described above will calculate a MaxT time specifically for each milking session (e.g. AM/PM). This can complicate practical implementation or lead to inefficiency. For example, due to uneven milking intervals the target afternoon milk time could be as low as 5 min, which could be difficult to achieve, or for those implementing via ACRs it requires a manual change of settings between milkings.
One work around suggested above is to use the AM MaxT time at both milkings, however, this will leave unrealised efficiency in the afternoon. An alternative approach called FixedT can be used to determine the MaxT time based on the average yield per milking (see Table below) and use that time at all milkings, ignoring differences in milking intervals – shifting milk from the longer milking to the shorter milking.
Research has concluded that this approach will not compromise milk production as long as no more than 33% of cows have their milking shortened. This means that if your milking interval does not diverge too much from the average interval of 12-12 h (TAD) or 16-16-16 h (3-in-2) then this 33% threshold is unlikely to be exceeded and the FixedT approach can be used.
In the experiment, which also used a 70:30 pulsation ratio to increase milking speed, fat production was affected when the TAD milking interval was 8-16 h. In this herd 40%+ of cows had their milking shortened at the morning milking due to it being 4 h divergent from the average 12-12 h interval. Conversely, there was no affect for a TAD 10-14 hr interval, which is only 2 h divergent from 12-12.
For 3-in-2, a 10-19-19 hr interval was tested, where the longer milkings were 3 h divergent from 16-16-16. There was no affect on production in mid-lactation, but there was a tendency for a reduced fat yield at the mid-morning milking in peak lactation where 36% of cows had their milking shortened.
For those looking to maximise their milking efficiency by using the FixedT approach to simplify milking and improve efficiency, monitor the number of animals that have their milking shortened (see Step 3) to ensure it is not more than 33%. In some cases this may require an adjustment to your milking interval.
Daily milk yield
Once you have your MaxT time the next step is to implement it in the dairy. Choose which system you will use to help you keep track of the MaxT time when milking. The most common options are:
- Use the first cow in the row to time the MaxT time for all the cows in row by:
- a timer visible from anywhere in the pit, or
- a phone with a timer, or
- set a maximum milking time with your Automatic Cup Removers (ACRs).
There are three key elements to a good routine when you are using the first cow to set the MaxT time for the row:
- Start the timer as you attach the cluster to the first cow in the row, and work your way down the row attaching clusters in order. By keeping a consistent routine and order of cluster attachment for every row, this first cows acts as a timer for all cows in the row.
- After cupping the row and completing all other tasks, return to the front of the pit and wait for the MaxT time to be reached. Then change cups by working down the pit in order without waiting for any cows still milking, keeping that routine consistent.
- There are two options for teat spraying depending on your dairy. Spray as you go in your normal ‘bunny hopping’ routine, or because of the consistence of the MaxT routine, some milkers find it easier to teat spray after changing all cups in the row. With a MaxT milking routine you end up with all your waiting time at the front of the pit rather than at individual slow cows, so you tend to have more time to teat spray and exit cows.
Note: if part of the herd is milked once a day, put these cows in one herd and allow them additional time.
Herringbone MaxT routine – milking smarter
This video shows MaxT in action during peak lactation and demonstrates how simple and relaxed the milking routine becomes
When using MaxT, in order to keep the time consistent for all cows down the row, we recommend teat spraying after changing clusters.
This differs from the basic bunny hopping routine where tasks are completed in batches.
The final step is regular monitoring. Once a week at an afternoon milking monitor five groups of 10 cows. When monitoring, look at the cows as clusters are changed (i.e. once the cluster has been on for the MaxT time).
- If most groups have fewer than two cows that are being shortened, you can reduce the MaxT time.
- If most groups have more than two cows that are being shortened, increase the MaxT time.
- If most groups have two cows in every 10 that are being shortened, you do not need to make any changes.