Inangahua Cow Barn Brings Nangahua Cow Barn Brings Huge On-Farm Changes

• Published date: 09 November 2022
• Publication title: West Coast Farming Times, The

The composting barn houses the farm's 540 cows in winter or during any wet periods

The barn was months in the building.

"It was used for the first time on May 19 this year. We finished the milking season using it. Because we had the barn, we could take cows off pasture once they had eaten the grass, then top them up with feed in the barn. We would normally send our cull cows off mid May but carried 80 extra cows up until the last day of the season on June 13," Matt said.

The O'Regans had been interested in the idea of a cow barn for a long time.

"I had viewed barns in other countries and I always liked the idea of having the cows inside due to our weather conditions," Matt said.

However, Matt and Carmel said they did not like the idea of the cows being on concrete and all the added effluent issues created by that system. It wasn't until they saw a composting barn in action that they decided they had found a system that could work for them.

The composting system uses wood chips as a base.

"It gave us a barn and solved the problem of the cows being outside in the wet as well as somewhere for them to lie down. Ideally it operates at a ground temperature of about 40 degrees.

"We have employed a 'cow barn' specialist consultant to help us understand both the nutritional concept and maximizing the benefits of the barn with a predominantly grass farming system." The O'Regans have found there has been a bit of 'trial and error' involved in getting the system right.

"We lost temperature with the damp wet days during winter. The lost heat meant the compost went sloppy on top. We had to take the top layer off and add more dry chip which did work and the temperature is now around 38-40 degrees," Matt said.

The compost is 'ripped', every 24 hours to aerate, using a deep ripper on the tractor. The idea is that the wood, poo, pee and oxygen create heat which makes the compost system work.

"The base layer of woodchip in the shed is 800mm deep. We are cultivating or aerating it down to about 500mm, and below that remains clean woodchip." Beneath the barn is an underground drainage system to collect any wastewater in a tank, but so far nothing has emptied into it.

"It is unlike the concrete floored barn which accumulates all the effluent," Matt said.

The O'Regans had Coastwide Forage Solutions supply logs and chip them on site.

"Ultimately for us will be if we can log our own beech forest that has already regenerated from logging in the 1960s-80s, allow it to regenerate...