Weird farm facts: what does a cow and a hair dryer have in common?

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Yep, it’s a heatwave. Dairy cows hate heatwaves. How much? Take a look at some of these weird facts from Dairy Australia’s Cool Cows website:

  • Each of our dairy cows gives off body heat equivalent to a 1500-watt hair dryer on a hot day.
  • Cows eat 10-20% less when the air temperature is more than 26°C.
  • A cow making more milk is more easily heat stressed.
  • Each dairy cow can drink 200-250 litres per day in hot weather – double the normal intake.
  • A heat stressed cow makes less milk for one to two days afterwards. If she’s heat stressed for two days in a row, milk production can be affected for a fortnight.

Suffice to say, the weatherman has our attention. Farmer levies fund a Temperature Humidity Index (THI) forecast that gives us a heads-up on just how tough it could be on the cows.

A THI of over 68 has a measurable impact on milk production, not to mention our cows’ wellbeing. As you can see, the forecast has us reaching a THI of 83. Nasty.

THI

THI Dairy Forecast http://dairy.katestone.com.au/

We’re onto it. To help keep the cows cool, we milk earlier in the morning and later in the afternoon when the sun is low.

The cows have a paddock with enough shade and water for everyone that’s close to the dairy. We serve up a light meal of silage just beyond the trees, so they can sneak out from the shade, have a nibble and go back where it’s cool for a nap.

The dairy yard is sprinkled with water, giving the cows a welcome shower while they wait to be milked. Inside the dairy, ceiling fans whir above the cows for maximum comfort.

There are three water troughs on the way to the night paddock, which is a juicy crop of emerald-green millet. Better than being at the beach!

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What climate change means at farm level

A photo by Heather Downing of the kids and me out on the farm for the Earth Hour cookbook, which appeared in The Age today

When journalist from The Age Liam Mannix asked me how climate change was affecting our farm, the answer was: in every possible way, beginning with the circle of life.

When I was a girl, we used to get the ute, the tractor and our gumboots bogged every winter. It rained and rained and rained and rained and…you get the picture. Well, not any more. With the odd exception, the winters are warmer and drier these days. Boggings are a rare novelty for my kids.

This has some real benefits. Warmer, drier winters are much easier on the cows, calves and the grass. Much easier on us, too (plugging through deep mud in horizontal rain is character-building stuff)! We can grow a lot more grass in winter and that’s fantastic.

Less than fantastic are the changing shoulders of the season – sprummer and autumn. Spring can come to an abrupt halt very early in November these days and we often wait much longer into autumn for rain.

Every rain-fed farmer like me tries to match the cow’s natural lactation curve with the grass’s growth. In fact, the amount of grass the cows harvest is the number one predictor of dairy farm profitability. So, looking at the new growth patterns, we took the plunge a few years ago and shifted the circle of life to match. Now, calves begin to arrive in early May rather than mid-July.

Our decision is backed by hard data. Dairy guru, Neil Lane, has researched local statistics and found that farms just 10 minutes away have seen falls in production of 1 tonne of dry matter per hectare and increasing risk around late spring and autumn. On our 200 hectare farm, that’s 200 tonnes every year valued at roughly $300 per tonne we lose. That’s a lot of ground to make up.

But all is not lost. Dairy farmers are adapting at break-neck speed. We are on the cusp of breeding cows that are more resilient to heat and, in the meantime, have a very well-practised regimen to protect our cows from heat stress.

We are growing different pasture species like cocksfoot, tall fescue and prairie grass with deep root systems to tap into subsoil moisture. Planting at least 1000 trees per year creates micro climates that shelter both our animals and our pastures.

All of this makes practical, business sense and it also helps me feel better about our children’s futures. We are doing something!

That’s why I agreed to talk to The Age for this article and why we were happy to be featured in the Earth Hour cookbook.
It’s thrilling to see the great stuff farmers across Australia are doing in response to climate change. Now, if we can communicate that to foodies and the animal welfare movement, just imagine the possibilities.

The Earth Hour cook book makes climate change matter to foodies

The Earth Hour cook book makes climate change matter to foodies

Cows on top

You and whose army?

You and whose army?

Cows rule, okay?

No dairy farmer worth her salt treats a cow as anything other than a queen. A cow track is only fit for a cow if her farmer finds it comfortable barefoot, a perfectly balanced dinner must arrive at the right time and in the right portion or there will be hell to pay and, most importantly, it is the cow who sets the timetable.

Milkings should be as evenly spaced as possible and the cow is a masterful timekeeper. If we are half an hour late, she will arrive at the dairy demanding better service and if we are early, well, we must simply wait for her to gather herself.

With all this in mind, I should have known better than to cut it fine rounding up before my regular rendezvous with the school bus. They should not, would not be hurried.

Cow comfort is actually a big deal for dairy farmers. We spend a lot of time worrying about (and researching) resting time, dairy ventilation, “traffic” flow, yard design, walking surfaces, excessive noise and avoiding heat stress.  The biggie when rounding up for milking is to just let them come in gently. Yep. Should have got out there 15 minutes earlier.

Hot milk

Remember yesterday’s 41 degree Celsius heat? Now, imagine you were standing outside in it being blasted by 250 1500-watt hair dryers. How do you feel now? Ready to do athletics?

Grazing the lush crop

Icy poles for cows

Believe it or not, each of our dairy cows gives off body heat equivalent to a 1500-watt hair dryer on a hot day. Yet, incredibly, each still made an average of 29 litres of milk for us yesterday. We nursed them through with some very careful planning based on the principles of the Cool Cows program.

  • Wayne got up an hour earlier to milk before the sun’s rays began to sting and milked two hours later than usual. This meant that the cows spent less time in the sun on the concrete yard waiting to be milked.
  • We hosed the whole yard down about 45 minutes before the afternoon milking. It’s amazing how much cooler the yard felt afterwards.
  • The yard sprinklers were activated as the cows came towards the yard. (You remember the fun of dancing through sprinklers on the lawn!)
  • The cows’ diet changed a little for the day. The cows got a little more grain, a little more green crop and a little less hay yesterday. It takes more energy to digest high-fibre foods, which adds to heat stress. Rather than feeding out the hay during the day, Wayne stayed up late and offered the cows a “night-cap” in the relative cool of the evening.
  • We chose the coolest paddock on the farm, ringed by the deep shade of mature willow trees.
  • On a hot day, dairy cows can slurp up a staggering 250 litres each. Our extra-large troughs ensured they had plenty of fresh, cool water to drink when they chose to emerge from their hideouts.

Poor girls. According to the Cool Cows program leader, Dr Steve Little, dairy cows start to seek out shade when it gets to about 25 degrees C. I think the farm’s cows, dogs and humans all felt the need to go into summer hibernation yesterday.

Making up for the heat

Do you tend to eat less in the heat? I do and so do our cows. This is the third day of hot weather here and there’s another on its way.

Once the mercury rises over about 25 degrees Celsius, the cows begin to find it uncomfortable. We’ve sent them to a shady paddock for the day and to make up for the fact that they’ll spend most of it under the spreading branches of the willows, we’ve also changed their feed pattern.

Shady paddock

A cool spot for a hot day

According to the gurus at Cool Cows:

  • Cows will eat less overall, so increase the energy density of your diet where possible. More starch or added fat can be useful tools.
  • The risk of ruminal acidosis is increased during hot weather by several factors:
    • Cows prefer to eat in “blocks” in the cooler times of the morning and evening each day in hot weather;
    • Cows tend to select against low quality forage/fibre; and
    • The natural buffering system the cow relies on to combat ruminal acidosis does not work as well in hot weather.
  • Feeding of a high quality fibre source in the diet that helps maintain a stable rumen, but still contributes energy rather than just gut fill, is therefore essential in hot weather. For high-producing herds already being fed plenty of starch via grain / concentrates, this is particularly crucial.
  • Recent research work in Arizona (where they know a bit about heat!) suggests that heat stressed cows switch metabolism and have an increased need for glucose within their bodies. Feedstuffs and feeding strategies that either provide the cow with more glucose or spare the amount she uses in her normal body processes may therefore be useful in hot weather.

For these reasons, they’re getting some extra grass tonight in a fresh new paddock. What about the farmers? Lots of refreshing baths for baby Alex, the minimum of farm chores and an early morning sojourn into the cool forest.

A cool place to hang out

A cool place to hang out

Our cows are so cool

Our cows are dignified ladies who like to keep their cool in more ways than one. Bred in cooler climes than Australia, Holstein Friesians start to feel the heat once the mercury climbs over 25 degrees Celsius.

We’ve been really busy preparing the farm to help them deal with hot summer days:

  • planting thousands of trees for shade

    New plantation for shade and wildlife

    New plantations will provide shade for the cows and corridors for wildlife

  • installing 4 kilometres of large capacity water pipes and 17 massive water troughs. Milking cows can drink up to 250 litres each on a hot day or 20 litres in a minute!

    Water trough

    Installing water troughs has been a 3 year project

  • putting up sprinklers in the dairy yard to offer a cool shower while they wait to be milked and

    Yard sprinkler

    A shower cools the cows, the concrete underfoot and offers relief from flies

  • adding salt, minerals and zinc to their diets.

    Feed in the bail

    Zinc is added to the cows' feed during summer

I also select the paddock for the day with a keen eye on the forecast. Today is pretty uncomfortable, so they’ve been sent to a paddock ringed with trees and will graze a more open paddock tonight.

Cool cows are happy, healthy cows who make more milk, suffer fewer illnesses, carry pregnancies better and are nicer to work alongside! Dairy research body, Dairy Australia, has done lots of work on heat stress in dairy cows and you can access lots of useful info at the Cool Cows website.