Measuring Milking Routine Results

Having looked at the milking routines in hundreds of farms I still find it hard to judge whether the routine does the job or not by just looking at the routine. Using the information collected by the milk meters helps me to monitor the results of the milking routine. Hope this will help understanding the milking routine and put focus on what is important.

The milking routine has several functions, all are important, but priority has to be on he cow. I define the functions and priorities of the milking routine as follows:

1. First of all, the milking routine should result in the cows letting down the milk completely. After observing milking routines in New Zealand (just put the cups on), USA (various) and China (strip-dip-wipe-attach and other routines) my conclusion is that some routines result in good milk letdown, and some routines seem to "confuse" the cows, resulting in poor letdown.
2. Secondly, the milking routine should result in milking only cows with clean and dry teats. This sounds easy but when looking closely at teat ends after the teats are dipped, soaked and wiped often they are not really clean before unit attachment.
3. Thirdly, most farms also strip the cows for mastitis detection, not stripping long enough for the cows to let down the milk.

As hygiene is easier to inspect than milk letdown many farms have a tendency to design the milking routine with hygiene as priority one. This is a grave mistake, as the consequences of cows not letting down the milk are far worse than the risk of milking few cows with some dirt on the teats. Poor milk letdown results in longer milking duration, extending the time the cluster is on the cows. Long cluster-on time will result in teat ends staying open longer after milking and in higher percentages of cows with hyperkeratosis. Both conditions increasing the risk on mastitis infections.

Figure 1 shows how much the risk on new mastitis infections increases with increased roughness of the teat ends (research done by Gentilini et al 2016).

How well the cows let down the milk can be learned by analyzing the milk flow data from the herd management programs available on many farms. The following points explain the meaning on the most important parameters:

1. Peak flow. Milk flow out of the udder happens in 2 stages: First the cow transport the milk from the udder tissue to the cistern and the teat, from where it can be extracted by the machine. Peak flow can only be high if both processes work well. Fast milking cows can have peak flows exceeding 7 kg/minute, showing rapid flow within the udder and out of the teats. The average peak flow of well performing farms is always over 4 kg/minute, peak flows below 4 kg/minute are an indication of problems. The problem can be machine related in theory, but most often it is related to the cows not letting down the milk. Visible signals of low peak flow can be increased liner slip and purple teats after milking.
2. Percentage of time in low flow. This parameter is a good indicator of over milking. Over milking happens when milk flow out of the udder is less than flow out of the teats. This can happen at the start of milking, in the period 30-60 seconds after attaching and also at the end of milking. If you manage to have the low flow % below 10% you are doing a good job, if it is higher than 20% the risk of damage to the teat ends is high.
3. Milk flow development in the first 2 minutes: 0-15 seconds, 15-30 seconds, 30-60 seconds and 60-120 seconds (as measured in DeLaval Delpro). The target is to have a continuous increase in flow and be close to peak flow in the second minute. Common values see in good farms:

• 0-15 seconds: 0.8 kg / minute
• 15-30 seconds: 2.5 - 3.0 kg/minute
• 30-60 seconds: Over 3.0 - 3.5 kg/minute. Important is that this period is significantly higher than the previous period. If this average value is almost similar to the previous number it indicates that a high % of cows show bi-modal milking. This will also show as a higher % of time in low flow
• 60-120 seconds 3.5 - 4.0 kg/ minute

Note that the values are for farms milking 3 and 4 times daily with yields of 10-12 kg milk each session. Higher yielding farms will have higher flow rates, lower yielding cows will have a bit lower rates. Essential is the continuous increase, not the absolute level.

The amount harvested in the first 2 minutes and the % harvested in the first 2 minutes are also good parameters but they are linked to the above flow rates. The above values result in 6-7 kg milk harvested in the first 2 minutes

The last parameter to monitor is the milking duration, measured as the time the cluster is on the cow. Good duration targets are 4 minutes for 10-12 kg milk (average flow of 2.5-3.0 kg/minute) and less than 5 minutes for 15 kg milk (avg flow of > 3 kg/minute)

In a following article I will explain the settings of the milking machine that can help keeping the machine time short.