Happier cows will make more milk

Many seasoned dairy farmers at the Dairy Women’s Network conference thought they had a good grasp of such things but Chris Leach, DairyNZ developer, animal husbandry and welfare, surprised many with the answers. Understanding why and how cows react to us is the basis of good stockmanship and unwittingly stressing cows can cut production up to 10%, he warns.

Surprising fact number one, Leach revealed, is that a cow’s field of vision is 330^o. Many workshop participants thought it was much narrower, but they evolved as preyed-upon animals so a wide field of vision was an advantage.

With such a wide field of vision, they are wary of anything that disappears into their blindspot behind them: if you do, you risk being kicked or making the cow turn round.

To the front cows have a limited area of binocular vision so cannot judge distances or depth well: they need time to check steps or changes in layout. Vertical vision is limited to about 60^o. “Cows are designed to look down; if they have to look up they can’t see where they are placing their feet.”

A project where Leach and colleagues had to use a cherry picker amongst a herd showed the limits of cows’ vertical vision: once the cherry picker was above a certain height the cows were unconcerned because they couldn’t see the operators.

Cows’ colour vision is also limited. They see a spectrum of blues and yellows – about 100,000 different colours – compared to humans’ ability to see about one million. If you take red tones out of vision, contrast increases markedly and shadows look extreme, explains Leach. Consequently a block of shadow can look like a hole to a cow. They get used to shadows they see daily, but something different will throw them.

Smells are another driver of behaviour and cows can smell things up to 8km away. It’s a very important sense for the animal, notes Leach.

“It can have a devastating effect on cow flow if you are not aware of it: for instance, home-kill or someone spreading blood and bone.”

Herd hierarchy is strongly linked to smell, as shown by experiments that found social order among cows unaltered by blindfolding.

Cows can smell fear in the form of pheromones in urine, sweat and dung of other cows. A fearful cow in the milking shed sends a sensory message to others through her pheromones in urine or dung.

“Think about creating the dairy as a safe zone for cows and they will be far more ready to come onto the platform... Try to keep painful procedures out of there if you can.”

Given what cows eat, many workshop participants thought their sense of taste must be dull, but it’s better than humans’. Cows have two to three times as many taste buds as humans, using them to identify good, bad or toxic food, hence the need for sweeteners to mask bitter flavours such as zinc in water, but also the danger in loss of bitterness where toxic plants have been sprayed off or conserved.

High pitched noises, such as whistling, are unpleasant to cows and studies show shouting and whistling can be more stressful for the animal than being slapped or hit – not that the latter is acceptable either. As for what to have on the radio in the shed: research has shown country and western is the best.

Cows are sensitive to touch and feel pain as we do. However they are prey animals and try to hide pain. Do stroke, scratch and lightly pat cows, says Leach.

Fellow DWN conference speaker and dairying specialist Mel Eden says spending a lot of time in dairy design and management brought him to the conclusion we needed to understand cows better. “The attitude of the person will affect the cow.  With good attitude you get the benefit of calmer cows and better production.”

An excellent exercise is to measure how quiet cows are: with low fear you should be able to walk within 2.3m without a reaction; with average fear 5.3m; high fear 12m. Eden suggests using the reaction distance as a tool to measure the impact of management changes.

Leach says it will take three to six weeks for better handling of the herd to be translated into cow behaviour.

One farmer said they had top staff but they could be impatient. They did an experiment timing staff doing a rushed milking and then a calmer, less stressed one. 

It was timed from the start of milking to wash up, because stressed cows excrete more.  The rushed job was no faster. 

The experiment had given staff more acceptance of the need for calmer milking.