Cows welcome winter barns

Scientists are trialling a cow barn to see how it affects cow health, milk production and farms' environmental impact.

The arrival of cow barns in dairying has brought about the study which is analysing the effects of them on cows, nitrate leaching and pasture production.

Scientists say the barn option is far removed from factory farming and will combine temporary cow housing with pasture grazing.

A display of cow beds for the barn is at the three-day Central Districts Field Days at Feilding ending Saturday.

The free stall barn has just been completed and houses 200 cows when the soil is too wet to graze in the winter and early spring. Then they go out to graze pastures as much as possible to harvest the spring flush.

They will also be housed at night through autumn to reduce urine patches and nitrate leaching.

The housed herd will be compared as part of a regional study for the national Pastoral 21 programme with a 200-cow herd outside year round with only a feed pad. They will be monitored and compared for milk production, cow health and how happily they take to the barn.

The housed herd will also be observed for how well they accept different bed types and what affect it has on lameness, mastitis and milk production and how it affects pasture able to be harvested by cows.

Massey University research officer Christine Christensen said the research would run for three years and would help farmers comply with their nutrient caps and provide them with practical information and economic options.

She said the initial observations were that the cows were happy to be in the barn.

"So far so good and they are pretty peaceful and it's like a flash feed pad at the moment. They come in and get their supplementary feed and rest and ruminate on their beds.

"It's just like a paddock except they are not sitting on grass, they are sitting on different products and they have a roof over their heads, so if it's really hot they have shade and if it's cold they get some shelter. "

Christensen said there was a big difference between winter barns and factory farming.

The winter barns were a tool to help farmers increase productivity and reduce their environmental footprint, and that was wanted by farmers and kiwi and overseas consumers, she said.

"Cows are always going to graze outside in New Zealand. When there is a snow storm and the soil is saturated ... I have seen cows come in in the middle of winter and they have smiles on their faces because they don't what to be up to [their] bellies in the mud."

The research team will include animal scientists and veterinarians to monitor animal welfare, as well as soil scientists, effluent specialists and farm management experts.

Unlike some barns, which cows can enter freely, in this case the cows are controlled, being put out to pasture and then housed in the barn as needed.

Commercially there are many bedding options for barn cows including deep sand beds, bark chips and foam.

The Massey barn is trialling the different options of a commercial foam mattress covered in canvas, a rubber material and a modified sand bed designed in New Zealand. The shallower sand bed reduces maintenance and reduces sand in effluent, which can be hard on bearings and pumps.

The barn has automatic scrapers, which remove effluent from the barn floor which goes to a sewage pond. It is applied to pastures two to six times a year early in the season when nutrients are needed the most.

Cow barns are a relatively new concept in pasture-based farming in New Zealand, but they are an old concept in the northern hemisphere where cows are housed virtually year round and during harsh winters.

"The farmers are trying to protect their soils in the winter as well as providing a comfortable environment for their cows prior to calving," said Christensen at the field days.

"But we can also use cow barns as a way to help other things on farms we are trying to look at, such as ways farmers can use those facilities to increase production and reduce the environmental impact on the farm."

"New Zealand is based on our grazed pasture systems and we have got a perception with our overseas markets of being clean and green. So our country has got green grass, blue skies and clear water.

"Nutrient loss from farms is becoming a big issue, particularly nitrogen and phosphorous from urine spots for nitrogen and dung pats for phosphorus, and we have to reduce impacts from those nutrients on our waterways and we have to come up with solutions that are economic and practical for farmers to use so that's why we are going into research using cow barns."

Massey has done a field study with cows grazing for  four hours twice a day and over three years a reduction of 52 per cent of nitrate leaching was found.  

After grazing as much pasture as they could, the cows were removed and placed on a stand off facility and a barn to collect the urine and effluent and return it to the paddock evenly to increase pasture production and reduce nitrogen and phosphorous losses.

The winter barns also prevent cows pugging soils during wet months in high rainfall areas. Removing cows is important because soils turned over by hooves can destroy pasture and reduce milk production.

More cow barns are going up in the South Island where winters are cooler and a handful are in Manawatu.

The regional farm trial has national implications for dairy farmers, said Christensen.

Fairfax Media