22 December 1995

Slotted roofing eases stress

IMPROVING the ventilation of winter housing by cutting slots in the roof has increased feed intakes and cow performance on one Staffs dairy unit.

ADAS senior consultant David Levick recommended cutting slots in the barn roof when heat stress reduced the performance of the 140-cow herd during the mild autumn weather.

"Good ventilation puts less stress on animals and they perform better," say Mr Levick.

Because ventilation reduces humidity, it may also reduce lameness incidence. Cows produce more urine, which is also more acidic in humid conditions, and this is harmful to their feet, he claims.

The cow shed at Dunstall Hall Farm, Abbots Bromley, Rugeley, houses two groups of cows. The side housing middle yielders, including many heifers, suffered poor ventilation because the side was closed in.

The building also has a low roof reducing airflow, and is close to another building. So on this side of the roof Neil and Martin Brown cut 12mm (0.5inch) slots down each cement fibre roof sheet with a disc cutter.

Three weeks after the slots were made, they noticed the building was more airy and the cows happier.

"Silage intakes of the mid-yielders have increased by up to 2.5kg a cow a day," says Neil Brown. "During recent foggy weather they were not sweating as would have been the case before – and cubicle beds are drier."

No alterations were made to high yielders side of the building that is Yorkshire-boarded.

"But we are now tempted to slot the roof on the high yielders side to make that airier too," says Mr Brown. One concern could be that when rain falls directly down it may come through. But there is usually some wind and so far rain has failed to cause problems, he adds.

The slots in the roof at Dunstall Hall Farm are very obvious from here, and the animals are happier. From the outside the change can hardly be seen.

Martin (left) and Neil Brown took a disc cutter to the cement fibre roof sheets of their cow shed, and now its far drier inside.