MaxT is a strategy where cows are milked to a pre-determined end point, either a fixed time point or set milk flow rate threshold (if using automatic cluster removers).
The idea is to estimate when about 80% of cows have completed milking and to simply remove the clusters from the remaining 20% even if unfinished. In most cases milkers do not need to wait for slow milking cows to milk out.
Is MaxT for me?
MaxT can be used in any type of milking system but will not suit all situations. Because it reduces rotation times, it relies on the operators being able to speed up their work routine. In most rotaries this is easy to achieve.
In rotaries, operators have traditionally set the platform speed so that 10% of cows ‘go around’. This normally results in platform speeds slower than efficient operators can attach clusters, also resulting in idle time.
Using MaxT to minimise idle time will then help milk the herd in a shorter time.
The effect of two end-of-milking criteria on milking efficiency
The table below shows the effect of increasing ACR threshold from 0.2 to 0.4 kg/min or applying a fixed maximum milking time for a 770 cow herd in a 50-bail rotary with a herd average milk yield of 12 L/cow (e.g. a morning milking).
When increasing ACR thresholds it is important to simultaneously reduce the platform rotation time.
ACR threshold End-of-milking-criteria Normal (0.2kg/min) 0.4 kg/min 0.4 kg/min MaxT Rotation time 9 min 9 min 7.5 min 8 min Go-around cows 12% 4% 16% 0%* Available cupping time 12.1s 11.3s 10.4s 9.6s Cows milked per hour 298 319 345 375 Herd milking time 2:35 2:24 2:13 2:03 Saving 11 min 22 min 32 min
*23% would have 'gone-around' but clusters were removed.
So how do I apply MaxT?
An efficient work routine, cupping technique and shed design help to give you the full benefit of MaxT.
- Make sure herd cell count is below 200,000 cells/mL because if it is above 200 000, it is a higher priority to improve cell count than focus on efficiency.
- Identify any elite cows (yield of more than 30% above herd average). You may want to let them 'go around' in a rotary so they get more time to milk out.
- If there are cows with odd shaped udders that have trouble milking out (usually older cows) you may want to treat them separately and not under-milk them.
- In a rotary, the appropriate MaxT time for the herd is determined by the herd milk yield for the fortnight. Look this up from the MaxT table or use the milking efficiency calculator. It is easiest to do this at or after peak lactation when the yield is known. This will become the rotation time.
- Use the milking efficiency calculator. By entering some basic farm details you can estimate the amount of time that can be saved for your situation.
- Some models of automatic cluster removers can be set to a maximum milking time; on others you need to increase the low flow threshold from 0.2 to 0.4 kg/min. If this is increased to 0.4kg/min it will produce a similar result to a fixed time end point. If you are unsure how to change the threshold, contact the manufacture.
What does the research say?
Leaving residual milk in the udder goes against a long held industry belief that it will cause lost production and mastitis.
Milk is held in two compartments of the udder; the cistern (a bag above the teat) which holds roughly 20% and the alveoli (the cells where the milk is made) which holds the other 80%. When clusters are attached, the milk harvested in the first few minutes is from the cistern, then the milk ejection or let down reflex is triggered. This causes the remaining milk to move from the alveoli into the cistern where it can be harvested by the machine.
Detailed milk flow curves of normal cows show a greater milk flow rate during the first few minutes of milking, compared with cows whose clusters are removed early (MaxT). In other words, there is more milk being held in the cistern because it was left over from the previous milking. This milk is harvested immediately at the next milking without waiting for milk let down, so the milking duration is shorter and there is no net loss in milk production or increase in cell count.
Basically, the residual milk is retained to the next milking where it can be harvested faster.
Click on the gallery of images below to see detailed milk curves showing the effect of removing clusters earlier.
Journal Papers for further reading:
MaxT Case Studies
Mid Canterbury farmer Martin Furrer says his staff were sceptical when he announced MaxT was to be implemented in the shed for his 1250 cow herd but soon realised the benefits.
When Ben Januay heard about Max T, he couldn’t wait to give it a try - milking 2200 cows was just taking too long – even with a 100 bale rotary shed.
The benefit of applying MaxT in a rotary
This animated video demonstrates the benefit of applying MaxT in a rotary dairy.
To see a video demonstrating the concept of applying MaxT in comparison to standard milking procedure, click and watch the video below.