Giant shade structure keeps cows cool

By Stephen Cooke

A total mixed ration (TMR) system implemented in the early 90s has enabled Queensland dairy farmers David and Cindy Janke to remain profitable despite a static milk price, less rain and harsh summer temperatures.

The Jankes run 800 head and milk 400 Holsteins on Davindy Dairy at Westbrook, near Toowoomba in Queensland’s Darling Downs. They produce all their own silage for their ration and will start producing their own grain.

“We used to irrigate rye grass but we can’t do that now. People used to milk 30 cows back in the day and could make a living,” David said.

“We’ve run pasture-based and partial mixed ration systems before but we wouldn’t go back. TMR is the ultimate for a dryland situation.”

The centre piece of Davindy Dairy is a permanent shade structure, where the cows lie on a bed of saw dust and wood chip. It is located next to the 24 double up rapid exit herringbone dairy.

The shade structure (80m long by 14m wide by 4.5m high) was installed in 2010 and provides shade and bedding for the milking herd. The herd sits on a mixture comprising 50 per cent saw dust and 50 per cent woodchip, and when removed it makes “tremendous” compost.

“We take 2000 tonne to our block at Westbrook each year, spread it on top, and then cultivate it in for silage and corn silage.” It costs $6/t to cart the compost to their second farm and an additional $6/t to spread it.

The placement of the shade structure was important, and based on insight from their son Scott, an engineer. It was built running north-south, with a slight tilt to the west. This ensures they receive more summer sun then winter sun, and that the sunlight reaches the ground.

If it was built running east-west, they would not have received enough sun inside which would have caused problems with moisture. The shed is open so it has good airflow, crucial in the local humidity.

“We have the most efficient use of sunlight on the ground. It seems simple but that’s the key,” David said.

David said the right height is crucial for these structures and that if he built another, it would be slightly wider with a slightly bigger gap on top.

“The shade structure really helps our system. It was 43 degrees in the dairy last year and we didn’t lose production.”

The herd of 380 millking cows produces 12 000 litres/day, recording 4.3 per cent fat and 3.5 per cent protein. They send about 4 million litres annually to Norco, who they joined three years ago.

They use 8000t of silage each year through a TMR system which they started in the early 90s. They produce 10 000 t of silage each year and store it in concrete bunkers.

The TMR ration consists of cereal silage (oats or wheat), legume (dollicus lab lab or soya bean) in a good season, although it has been too dry of late).

Although not the typical crop used for silage production in southern Queensland, David has had good success using forage oats to complement starch-based corn with protein.

He harvests just before seed head emergence to optimise yield and quality to come up with a pit silage product with higher metabolisable energy and crude protein values than barley, which is the predominant winter silage crop grown in the region.

They conserve summer corn for their herd’s energy requirements and oats in winter for protein in a dryland situation.

While oats are typically used for grazing or making hay in South East Queensland, and barley is the predominant winter silage option, David said oats won out in terms of crude protein content and being low in fibre content if cut before heads started to appear.

“We cut at pre-flower stage so it doesn’t go to head. It has higher protein, lower NDF and is more digestible.”

This year they planted IT corn (Pacific Seeds 606) and Pioneer 1813 — and will compare them side by side.

Last year they grew 30t/ha of good quality oats, and aim for at least 20-25t/ha cereals. They can grow 38t/ha of corn and harvest two crops off from each paddock.

They were able to grow two crops of corn from each paddock because of their own compost. “With compost, you only need to apply an additional 150 kg/ha of urea per crop.”

However, they rotate now because they lease more land.

The Jankes have 200ha of lease country and 60ha of their own irrigation country and they plan to grow their own grain crops with the additional land.

They currently buy their grain — 55t/month wheat; 40t/month corn; 27t/month of soya bean meal; 22t/month canola bean meal.

If their plan to grow their own grain is realised, the Jankes will have turned their impressive operation into a model of self-sufficiency.