Herringbone MaxT

Farmers who've adopted MaxT tell us that it simplifies the milking routine. The most complicated part is calculating the maximum milking time (MaxT), which is based on how long it will take 80% of your cows to finish milking. When implementing for the first time, MaxT is typically applied at the morning (highest volume) milking. Calculate your MaxT time with the DairyNZ Milking App (Apple App store and Google Play store).

Herringbone: the time begins once the first cow in the row is cupped. Then, cup the rest of the row. Once the MaxT time has passed, take the cups off the first cow and work your way down the row changing clusters, removing cups from all cows.

MaxT doesn’t mean you have to work faster. In most cases, you’ll be working at the same speed or more slowly.

Herringbone: milkers who use MaxT say it provides a logical milking routine and less walking back and forward to deal with slow-milking cows. This allows for a longer break at the front of the pit while waiting for the MaxT time to elapse.

Meal feeding generally shouldn’t be a barrier to implementing MaxT. At peak milk, the full row/rotation time is likely to be between eight and 10 minutes, which should provide plenty of time for cows to finish their food ration. Farmers have found that, by implementing MaxT on rotary dairies with feeding meal, cow flow actually improves. The cows get used to exiting at the end of one rotation and there aren’t as many free-riders.

ACRs make implementing MaxT simple. For most devices, this is achieved by setting the ‘Maximum Time’ setting or ‘Point Takeoff’ setting (for rotaries) in the ACR to achieve the desired MaxT time (some models might need a modification from a service provider).

Another way is to lift the ACR low-flow threshold (similar to MaxT). For a rotary with one operator, set the platform speed to provide the required MaxT time between the cups-on and cups-off position, so more cows complete milking by the end of one rotation. Keep adjusting the low-flow threshold until you reach your desired balance.

Increasing pulsation ratio is a good strategy to reduce milking time in situations where the risk of overmilking is low – such as when using MaxT. Increasing the pulsation ratio will mean fewer cows are shortened than the estimated 20% for a given MaxT time. A key requirement when doing this is to achieve a d-phase of ≥ 20%.

• Set your pulsation ratio at 70:30 and pulsation rate at 55ppm if you have ACRs and are doing MaxT.
• Otherwise, set the ratio to 65:35 and rate to 60ppm if you are doing MaxT without ACRs.

Consult your milking machine technician to assist with changing your pulsation ratio.

No research or field study over the past 30 years has supported this theory. In fact, there’s a greater risk of mastitis when cows are overmilked at the end of milking. MaxT often results in a better let-down and removal of milk at the next milking for slower milking cows – and reduces overmilking for the rest of the herd.

Research shows that when a 500mL of strip milk is routinely left in the udder after milking, there’s no detectable increase in cell counts for both infected and uninfected quarters.

Anecdotally, we know that herds milked using MaxT often see a decrease in somatic cell count (SCC). As mentioned earlier, there’s a greater risk of teat congestion, damage and mastitis when cows are overmilked at the end of milking.

Contrary to common myths, using MaxT and leaving milk behind in the udder has no negative effects on milk quality, milk production or somatic cell counts.

Research in high-producing overseas systems does not support this theory. The most comparable study was in Denmark, where there was no significant difference in milk production or udder health when the ACR low-flow limit was doubled from 0.2 to 0.4kg/min, and cows were averaging 2.5kg MS/cow/d (32kg milk/cow/day).

Although there's been no research yet to specifically test MaxT with milking three times in two days (3-in-2) or once a day (OAD), farmer feedback suggests it can work successfully. DairyNZ is expected to begin an experiment into this in October 2020.