Milking cows in the heat
- Most northern dairy farm in South Australia is at Blyth
- The Entegra shed is 100 metres long by 41m wide
- Reducing feed wastage and increasing dry matter intake will be the first gains from sheltering the milking herd.
- Productivity and fertility have been their main breeding priorities but in recent years they have chosen bulls for their herd which have the feed saved genetic trait.
Australia’s Clare Valley is known for a lot of things.
Wineries and cellar doors are often the first that spring to mind.
Others might know the region for its growing reputation as a hub for quality export hay.
That’s without mentioning its longstanding and significant grains industry.
Take a drive north from Adelaide in South Australia and there’s a fair chance of encountering many of the livestock or crops which underpin some of Australia’s largest agricultural industries.
But there is one you are unlikely to see, dairy cows.
And there’s no one more aware of this than Blyth dairy farmer Gary Zweck, the most northern milk producer in South Australia.
For starters, if anything breaks down in his dairy, the closest technician is three hours away.
He doesn’t see this changing either.
So, when it came to investing in his business, Gary had to think strategically.
“I’ve got a fairly old dairy, but where I am, I don’t believe putting a rotary dairy in is a viable option because there aren’t many dairies around here,” he said.
“So, when we were choosing to build a shelter, the choice was to have a shed full of free stalls or just a compost shed. At the end of the day, if we stop milking cows, a compost shed becomes a great big hay shed.”
But this realistic approach hasn’t just applied to their new Entegra shed.
Gary, wife Ros and son Justin have kept all their options open for the future by ensuring they build a structure that is not flexible but will also last for a long time.
“Obviously if we put four robots in, they can be unbolted and resold,” Gary explained.
“It is not like having a million-dollar rotary there that no one wants to buy into. The area we live in is not really a dairy area, it is not recognised as such, and probably never will be, so I’m sort of hedging my bets.”
Replacing their aged herringbone dairy with four milking robots at the end of the new shed is a “no brainer” but this won’t happen for at least five years.
As part of the planning for the shed, Gary left space at the end of the installation for the robots.
The Entegra shed is 100 metres long by 41m wide and sits just to the north of the current dairy between two feed pads. The heifers have traditionally had one feed pad, while the milkers shared the other.
When the 240 Holstein milking herd goes under the shed permanently in autumn, the heifers will move across to the former milker feedpad.
Cows will continue to calve under an old hay shed, ensuring they are protected from the elements.
Moving across to a shelter-style dairy farming system won’t be much of a change for the Zwecks.
Unlike other dairy farmers making the move to provide permanent shelter for their herd, Gary, Ros and Justin have been operating a total mixed ration feeding system since 2001.
It’s the best match for the farm’s 350mm annual rainfall and enables them to produce their own feed.
The farm’s mostly self-sufficient with 771 hectares producing the dairy’s wheat and barley as well as oaten and vetch silage.
“It is basically what we are doing now, out in the open, all we are doing is going to try and do it under a roof,” Gary said.
“The pens the cow’s loaf in now, we harrow every day and try to maintain it, so it is dry on top.”
“That’s what we anticipate doing in the shed as well. The same sort of process, just under a roof.”
Gary doesn’t anticipate the shed saving them time, the jobs of bringing the cows into milk, harrowing the bedding and feeding won’t change.
But the family have budgeted for the shed to deliver a better return on their investment of time and money.
Reducing feed wastage and increasing dry matter intake will be the first gains from sheltering the milking herd.
“(With the feed pad) we had a few losses,” Gary said. “For example, when we have rain here, I have to scrape up feed off the pad that didn’t get eaten.”
“With less waste we anticipate better feed conversion and because of the shade, better fertility rates. Just generally more comfortable cows.”
Making life easier
Hills Farm Supplies Managing Partner Anthony Pearce has worked with the Zwecks for almost 20 years, helping to manage their herd’s nutrition.
Fully housed dairy systems are not common within his client base, but for the Zwecks he thinks it’s the ideal fit to help them manage the hot weather.
Summer temperatures at Blyth are consistently more than 30 degrees Celsius, with consecutive days of 45 degrees Celsius not uncommon.
Anthony’s anticipating an improvement in feed conversion and conception rates due to reduced heat stress, the latter helping to cap the herd’s average number of days in milk to drive efficiencies.
“If we can keep the days in milk down, we can improve milk production per cow and feed conversion,” he said.
“We won’t get the dips in milk production and we won’t get those drops in production
with the heat and the variation in feed intake. I still believe that with a cow, getting her back in calf, and going around again, is better rather than extending her lactation.”
Thanks to the shade of the shelter, the herd’s diet will require less tweaks to account for fluctuations in weather conditions.
“Where we were reducing their fibre on hot days, we won’t be changing rations,” Anthony said. “It allows for more consistency and continuity in feeding programs. Cows are creatures of habit and respond to the same things.”
According to Dairy Australia heat stress research, a cow’s feed intake can reduce by 10-20 per cent when the air temperature is more than 26 degrees Celsius. Other physiological changes include blood hormone concentrations, core body temperature increase and altered blood flow distribution, including changes to the blood flow to the gut, uterus and other internal organs.
The Zwecks herd averages 2.4kg of milk solids/day/cow or close to 10,500 litres/cow/lactation, from twice a day milking.
The 650kg animals’ individual daily feed intake includes about 23kg of dry matter including about 3kg of grain per cow/day in the dairy.
Milking three times a day is on the cards for the coming year as Gary, Ros and Justin move to “capitalise on the fact they will produce more” due the shelter.
While Gary “won’t hazard a guess” at the potential increase in production from the additional milking, he anticipates it would play a key role – along with improved fertility and better feed utilisation – in paying back the barn across five years.
The Zwecks have been breeding cows to suit their farming system and the weather conditions for many years.
Productivity and fertility have been their main breeding priorities but in recent years they have chosen bulls for their herd which have the feed saved genetic trait.
This Australian Breeding Value trait identifies animals that produce the same amount of milk with reduced feed maintenance requirements – in short – more efficient cows.
“We have always been looking at targeting high levels of production per cow mainly because we grow all our own feed and we can make a fairly balanced ration in a wagon,” Gary said. “If you are going to do all that work, you may as well get the most out of it. It’s high inputs in, and high inputs out. The cows seem to be able to handle it and I’ve been pretty impressed with the young heifers coming through, those that are two years old, they seem to adapt to the system fairly quickly and crank it out pretty well.”
The Zwecks heifers achieve about 80 per cent of the mature cow’s average production in their first-year milking.
Calving has traditionally been three times a year to maintain flat milk production.
For the past four years the family has supplied supermarket Woolworths for its Farmers Own milk brand. Woolworths pays the same price for milk all year, unlike some other milk processors, so this also suits the Zwecks sheltered and TMR farming system.
Long term goal
The idea of building a shelter has been at the back of Gary’s mind for the past 10 to 15 years, primarily as a better way to manage the heat.
But it was a trip to the US state of California in 2008, with their previous milk processor, that cemented the concept and its potential to increase efficiencies.
“To me, it was a bit of an eye opener at the time, those types of systems where they are getting the milking herd in for three times a day, that was standard,” he said. “At one, I was at the end of a shed and bus was waiting for me. I was watching the farm’s labor unit, which was only costing them the minimum wage, walk the cows into be milked. While that was going on, another bloke – also on the minimum wage – jumped on a little tractor and he went through and had a little thing on the side of the tractor that sucked up the sand to make the beds and pushed the manure out to the centre of the feed alley. Then someone else triggered the flood wash and then that tractor turned around at the other end and pushed the feed back to the cows so that when the cows walked out of the shed their bed was made and their floor was washed, and they had feed presented to them.”
Five years ago, a dozer created a shed site at the Zwecks farm, but that sat idle for a few years while the final decisions about the type of shed were made.
In the end, the family chose a compost style shelter for its simplicity and versatility. Less infrastructure underneath the 22-degree pitch roof, compared to a freestall barn, helps ensures it could be taken apart easily, if required.
The design, including a vented ridge running along the middle of the roof with a cap over it to stop rain, would also stand the test of time for Justin as he progressively takes over the family farm.
Gary said the shed was also wide enough to be converted into a freestall barn, if the farm plan changed.
Helping with the heat
Prior to building the shed, the Zwecks herd would gather underneath a strip of river gum trees for shade in the summer or under old hay sheds.
Often, the milkers would also return to the dairy earlier to spend a hot day under sprinklers.
Other routine farm tasks such as joining were timed around hot weather, if possible, with the conditions often dictating the type of semen used.
“We had an artificial insemination program when we saw those two 45-degree days (in early summer) coming up and I thought, ‘what do I do? Do I keep going?’ And I did, but wondered whether it was the smart thing to do. I tried to put them under shade to make them more comfortable.”
In another case, Gary chose to use a Speckle Park bull with a group of about 20 Holstein heifers, during a hot period, rather than spending money on an estrous synchronisation program using CIDRs and more expensive sexed semen.
Thanks to the Entegra shed, these “hard” economic decisions driven by the weather will be a thing of the past.
“We won’t have to change our plans for weather,” Gary said. “There won’t be concerns about them getting in calf or if we should be saving our synch programs and semen. Or we won’t be putting sexed semen into cows that won’t hold due to the hot weather. It will just be less stress, I would hope.”