Giving cattle room to breathe

Like all animals, grazing livestock need space to feed and hang out with their mates. Kerry Dwyer takes a look at how you can keep your livelihood happy and well fed.

I was recently asked how much space should be allocated to grazing cattle, for both feed and social reasons. While there is no magic formula, the question did give me cause to think about it as there are some consequences for the animals we tend.

Cattle are a social animal, whether in feral groups or domesticated. They have a personal space around them, invasion of that space will lead to fight or flight if the animal feels threatened. Humans and other species have exactly the same responses inside their personal space.

Undomesticated cattle live in groups of cows and calves, with bulls in separate herds. They have a social hierarchy within these groups, with interaction between the animals determining their position in that hierarchy. Note that the highest-ranking animals are seldom the most aggressive, they don’t have to be because they have already established their position.

Putting new animals into an established social group of cattle can result in some behaviour changes as a new hierarchy is sorted out. Cows and heifers will establish new relationships mostly without any aggression, while bulls may be more physical.

Studies have shown that calves reared without contact with adults will exhibit dominant relationships later than those reared on cows, that can be as late as approaching a year of age. Studies have also shown that groups reared together will form bonds that can last for years, and they will favour that group over others they are mixed with. The dominance-subordination relationships formed between calves and cattle are very stable and can persist for years, seldom being reversed.

Excellent vision

Vision is the dominant sense in cattle, with hearing and smell being less important in their lives. Cattle have a 330 degrees vision with binocular vision for only a small scope in front. To maximise that binocular vision, to judge depth and distance, they will lower their heads and face the point of interest. Their wide vision is adept at detecting predators, since they are the prey. While vision is dominant, cattle do identify others with hearing and smell if blindfolded, so a blind animal can move with the herd if given time and space.

As a natural prey species, cattle are fearful of new experiences. They have a good memory of their world, and can identify up to about 80 other individual cattle and maybe 15 humans. They like the familiar and a routine.
Considering all of this, how much space do we allocate our cattle for grazing and handling? Feedlots will allow between 20 and 80m2 per animal depending on age and size, which is far less than what a grazing animal experiences. There will be some consequences for the animals as a result. Social pressure will cause reduced feed intake and more stress in individual cattle, which will be exaggerated if groups are mixed together.

“They have a good memory of their world, and can identify up to about 80 other individual cattle and maybe 15 humans.”

Liveweight and personal space

A farmer once told me that the maximum number in a mob of bulls, for best management, was ten tons of liveweight. That might be 100 bull calves at 100kg, or 25 bulls at 400kg liveweight. The point he was making is that as they grow they become more aggressive and less tolerant of larger groups. That is probably a natural tendency, but may be exaggerated because the dairy sourced bulls we see the most of have been reared off their mothers and are trying to establish hierarchy for much of their lives, especially if mixed.

Steers and heifers are less aggressive than bulls but I constantly have feedback from stockmen that smaller mobs (e.g. 40 steers) grow far better than larger mobs of twice that size or more.

Studies have shown the personal space of cattle is between 3-5m around them. When other cattle or humans get inside that distance some response will be invoked, will it be flight or flight? When you move a mob of cattle the dominant ones will tend to move to the middle of the herd, because that is the safest place to be away from predators. The subordinate cattle will be pushed to the front or back of the mob.

How much space for growing bulls?

While there is no magic formula, think about the following:

Have they been together for a long period?

Do they have some hobbies? Cattle can spend over 12 hours not grazing,

So what do they do then? Standing by the water trough waiting for the next bull to come along might be the hobby.

Playing with a tree stump or a tyre may be a better hobby;

Can they hide from each other? Because they are such visual animals, the sight of another bull is enough to cause stress;

Are all the animals a similar size and age? The most dominant animals are seldom the most aggressive but if they are evenly matched then establishing the hierarchy may be time consuming. Bulls in techno systems have small watering points, which they learn not to stay around once they have had a drink. Because the troughs tend to be at a fence, that means social isolation for the individual, so they move back to the middle of the mob if possible. Bulls with larger troughs in the middle of paddocks have a far different outlook, being closer to the middle of the mob and the ability to have a number of animals there at the same time.

As mentioned earlier, cattle have a personal space of 3-5 metres around them. Put them into yards and they lose that personal space, so stress levels rise and fight or flight becomes more an option for them. Mixing mobs prior to yarding increases that stress. Recently, I saw a farmer yard separate mobs of bulls, first running the mobs most distant from the yards past the other mobs. They all got upset before even getting to the yards.

Feed allocation

The other aspect of the farmer’s question was about feed allocation.

The dairy industry has a reasonably well-established formula for calculating the area per cow per day of grazing allocation, especially for their first grazing rotation after calving. If you over-allocate the pasture in that first round then the cows can be under-fed in their second round. Spacing of 50-60m2/cow/day is not uncommon for that first grazing round. Few dairy farms will be able to allocate 90m2/cow/day and have enough pasture for their second round.

If the dairy farm has a pasture cover of 3500kg DM/ha available on those paddocks, that means there is about 10kg DM/cow/day available on that allocation of 50m2, the maths being 3500kg DM/ha available less 1500kg DM/ha residual, equals 2000kgDM/ha divided by 10,000m2/ha times 50m2/cow/day allocated. The cows will therefore need some supplement with silage etc.

Using the same pasture cover and formula for 400kg bulls, to put 20kgDM/hd/day in front of them means a grazing area of 100m2/hd/day. A mob of 50 bulls will therefore get a daily break of half a hectare. The feed supply may be adequate but with 100m2/bull there is going to be significant social interactions going on. Cutting the mob in half and giving a two-day break will reduce those interactions by more than half. You might lose some pasture control but the animals will be far less stressed. Water troughs in the middle of the paddocks are great for water supply but a magnet for bulls to hang around.

In summary, I am not a cow-whisperer, but I have constantly been learning that the animals we deal with have their own view on life, which we can adapt to. And I did read that “most tests of will between the handler and the cows are won by the cow”.

• Kerry Dwyer is a North Otago farm consultant and farmer.