Vetvice' opinion on free traffic versus directed cow traffic in barns with robotic milking

Published: 2012-08-31 22:13:00
Author: Jan Hulsen


Despite the fact that free cow traffic is the norm on robotic milking farms (in the Netherlands around 90% of farmers choose this option), we often get questions from farmers about directed cow traffic.


“What does Vetvice think about directed cow traffic?” they ask us. Or, in a more challenging vein: “why do you never talk about directed cow traffic – that works well too, doesn’t it?” And they often go on to cite one or more farms as examples.


Vetvice’s answer
We firmly believe that free cow traffic is the preferred choice, so the cows can always do their own thing without being made to wait. The animals can improvise continuously and make decisions based on the options available to them: visit the robot, go to eat or go to lie down. Directed or forced cow traffic has no substantial advantage over free cow traffic, but does put pressure on the cows’ use of time and entails higher initial costs for the farmer.


Where do we get this knowledge from?
Very little – too little – scientific research has been done into cow behaviour in milking robot barns and time use. Vetvice has conducted a number of surveys, including a study of ‘cross use’ of milking robots and a recent comparison of cow behaviour on farms with free cow traffic and farms with Feed First directed cow traffic. Our opinion is also based on our knowledge of cows and our experience on many hundreds of farms that we have visited, and still visit, for a variety of reasons.


In our eyes, DeLaval merits a favourable mention for the support they provided to Vetvice in our comparison of free cow traffic and directed cow traffic. As a milking robot manufacturer, DeLaval promotes both free cow traffic and Feed First directed cow traffic.


Why is there still interest in directed cow traffic?
We wonder that sometimes ourselves… First of all, it is our everyday observation that farmers who have no experience of milking robots and want to change over to a robotic system have a number of unnessecary uncertainties. As a result, their decisions are influenced by arguments that are actually irrelevant…


Provocative statement:
Directed cow traffic holds out a spurious solution for farmers afraid of losing control over their herd.


The insecure, inexperienced farmer
The inexperienced farmer wonders first of all if the cows will indeed visit the robot. The answer is: yes, they do. If a cow and her hooves are healthy and a reward awaits in the robot, she will visit the robot 4 times a day on average. After three weeks, almost all cows will ‘get’ it. Provided the farmer doesn’t do anything silly, such as urge them on too much.
Farmers also worry about cows that have to be fetched. But in a properly organised barn, fetching a cow is a piece of cake. So seek good advice when designing your barn. And if more than 5% of cows have to be fetched each time (you are fetching cows twice a day), there is something wrong with the hoof health or nutrition of the cows. And for this, directed cow traffic is not a solution: you need to tackle the problem itself.
To be perfectly clear: farms with directed cow traffic also have cows that need to be fetched! The next question is: what are those cows doing all that time? The answer is: they have spent hours unable to eat or lie down…


The salesmen
Milking robot salesmen sometimes strongly recommend opting for directed cow traffic. Besides “not having to fetch cows”, their arguments are:
1. more regular milking intervals, so better udder health;
2. better use of the milking robot.
They may be relevant, but these are not strong arguments.


Milking intervals are indeed slightly shorter, mainly because there are fewer cows with longer milking intervals. But it’s not all honey and roses.
The biggest gains are to be achieved with cows in early lactation, cows you want to be milked 4 times a day. If these animals are healthy and eating a correct ration, they visit the robot spontaneously 4 times a day. If they don’t do so, it is highly likely there is something wrong with them. Do you want those animals to be locked up in a part of the barn?
And every farmer with a high-yielding cow that is not visiting the robot readily wants to identify and examine that animal at an early stage. In a barn with free cow traffic, you stand a greater chance of stepping in early. And after examining the cow you can drive her to the robot or the treatment box, as you see fit.

In addition, in directed cow traffic the selection gate should have a counter that stops too many cows entering the holding area at the same time. Too many cows in the holding area causes a lot of stress among low-ranking cows, which also take a dislike to the robot as a result. Therefore, at peak times cows wanting to be milked are not directed to the robot and not milked until later. So these animals don’t have a regular milking interval.

In addition, it is debatable whether the slightly longer milking intervals for – take note – part of the herd actually make a difference…


The better use of the milking robot may not be all it appears to be. In directed cow traffic, only cows that actually want to be milked enter the robot. You save 1.5 refusals per robot. A refusal takes what… 15 seconds? So you save 23 seconds per cow per day. With 60 cows, this is a difference of 23 minutes per day or 1.7% of the robot’s capacity. This is the time taken to milk one cow, but it is only relevant if the milking robot is 100% occupied... Otherwise, the robot still has reserve capacity. And with a 100% occupied milking robot, the maximum number of cows needs to pass through all the selection gates and holding areas, with all the attendant congestion and stress.


Background: the cow
In a good barn with good feed management, cows eat 10 to 14 meals a day on average, ruminate for 8 to 9 hours (6 to 7 of these lying down) and spend 12 to 14 hours lying down. Limited access to feed increases the risk of metabolic problems and acidosis. As if that wasn’t enough, limited access to lying areas increases the risk of hoof problems.


The price paid by cows and farmer
The costs of directed cow traffic are twofold:
1. directed cow traffic requires a lot of selection gates and barriers, that are otherwise unnecessary. And that can break or fail. They cost money and pose a health and safety risk.
2. cows are forced to wait for longer, or to spend time in a part of the barn where they don’t actually want to be. This comes either at the expense of number of meals and feed intake, or at the expense of resting time. It won’t lead directly to an increase in cases of disease, or a sharp decline in milk yield, but it does put the herd under pressure. Low-ranking and weaker cows are hardest hit. So the farmer has to take greater pains to keep his herd healthy. And/or to accept a higher replacement rate.
In directed cow traffic, therefore, there is a shift in the balance of work from fetching cows to caring for weaker and low-ranking cows because these are under greater pressure than on farms with free cow traffic.


But some directed cow traffic farms run very well!
Perhaps this very same comment was on the tip of your own tongue? This is true. Those are farms where the farmer is very good at what he does.
Without directed cow traffic, they would run just as well or even better. And probably with less effort. I.e.: if the barn with free cow traffic is organised properly.


Let’s make it quite clear: directed cow traffic can work well. Provided the cows rarely have to wait at selection gates and provided the animals are able to eat and lie down enough. This means no more than one robot per group, or separating the robots so that each one has its own selection gate and holding area.
And not building any four-row barns. In four-row barns, there is much too little feeding space available for the cows. (Four-row barn: four rows of cubicles to one feed barrier.)


To summarise:
Farmers wishing to change over to a milking robot need to take the time to familiarise themselves with the work and management practices on a robotic milking farm. Otherwise they risk making bad decisions and missing out on opportunities for building an efficient, safe and animal-friendly barn.


So seek proper advice about your choice of milking system, barn layout and organisation of the work. From an independent adviser, such as a Vetvice Barn Design consultant.

And aim high in terms of labour efficiency, ease of work and cow comfort!


Jan Hulsen, 3 May 2012.

For more information on this topic, read the book ‘Robotic Milking’.

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