Huge roof lifts Ogilvie Group's beef feedlot |PHOTOS

The three separate covers at Airlie Feedlot, Apsley, Vic, stretch 810 metres from end to end - the equivalent of six football fields in length.

Each has huge 60m wide clearspans, ensuring there are no internal columns in any of the pens.

The project is a significant investment for the Ogilvie Group and will make them one of the few feedlotters in southern Australia offering solid shelter over their pens.

They have owned Airlie Feedlot for about 20 years and feed about 2500 cattle there at any one time.

The family-owned business is a major beef supplier to Woolworths, grain finishing about 11,000 head a year. The British-breed steers and heifers fed are either bought out of South East and western Vic markets and backgrounded before spending their final 60 days in the feedlot, or are cattle the Ogilvie Group have bred at their Lucindale and Kingston SE properties.

Barossa Valley company Rarcoola Structural has been in charge of the design and construction with 37 road trains of steel delivered to the site in the past three months by Mount Gambier-based Ray Scott Transport.

Airlie Feedlot manager Dale Smith says putting the feedlot under cover is about optimising animal welfare and maximising weight gains as well as preventing any fall off in weight gains over winter.

"Animal welfare is such a big part of sustainable agriculture nowadays," he said.

"Putting the cattle undercover will decrease incidences of weather driven events like exposure and hopefully will increase productivity.

"We get 20 inches (508 millimetres) of rainfall a year here so it can get cold and wet but the shade will be just as important on hot days - it almost draws its own wind with the ventilation."

Mr Smith says they were initially impressed with the design that has allowed minimal changes to their existing infrastructure.

"We didn't want to move all that much, we have moved a couple of little fence things just to get laser levels on our feed alley but other than that it has been relatively unchanged," he said.

There has also been minimal disruptions, with them still able to feed cattle while the feedlot has been a building site.

The 360m cover encloses 12 pens, the 300m one encloses 10 pens and there are five pens under the 150m cover, with each dirt pen holding 100 steers or heifers.

Mr Smith says it is too soon to know if the covers will reduce the number of times each year the pens require cleaning out but he is confident it will provide a more comfortable environment for both the cattle and staff.

"In winter it can get a bit cold and wet, going down the feed lane opening and closing lids and filling troughs and doing those monotonous jobs at a feedlot if you are undercover it is sort of easier," he said.

The first column was erected in mid January and Rarcoola has won the race against time to get it completed before the season breaks with 10-12 staff working on the project.

Rarcoola Structural business development manager Graham Dowie says it has been fantastic to tackle such a large scale project and have it completed in about 16 weeks.

"For us, for a company really in its infancy, it is so exciting to have a project like this," he said. "We were a bit worried about COVID delays and the weather but we have had a dream run."

Mr Dowie said he was conscious it may have been difficult to source the large tonnage of steel needed, with nearly 500 tonnes of heavy steel required, along with the other components.

"As soon as we were awarded the contract, we locked steel away," he said.

"The purlin and iron for the roof we had ordered three months before delivery - it wasn't as bad as we thought it was going to be.

"We have really good on-going relationships with our suppliers and and sourcing products from within South Australia."

Mr Dowie says the biggest challenge has been the project design - working around the existing pens, missing the power and water lines for the fences and troughs when putting down the footings to secure the cover and accommodating the fall in the pens.

"In the 360m x 60m one, there is a 2m fall from west to east and there is a fall from north to south so we have got four steps in the roof to keep the 5.5m high clearance," he said.

Stormwater flow was another major consideration, with the need to manage more than 30 megalitres of water on an annual basis.

"On the eastern side, because it is a 40m (wide) roof section, every column has 225mm round down pipes and on the western side (20m), every second column has 300mm round piping just to handle all the water," Mr Dowie said.

He says they are proud of their workmanship on the project and hope it may give other feedlotters ideas.

"It shows if your site isn't level what you can do," he said. "To level a site like this you are looking at millions of dollars to restart again but there are ways around it."