A wind of change blows through dairy blighted by illness
By Simon Wragg
Spending £1500 on improving ventilation at one Oxon dairy has improved cow comfort in a traditional 85-cow cubicle house, and is saving £10/calf a year in vet bills.
Martin Court, who farms 85ha (210 acres) at Mill Farmhouse, Shenington, near Banbury, says it was hard to ignore the signs of poor ventilation. "In the cubicle house, ammonia build-up was a concern. Tell-tale signs, such as cows breathing heavily and coughing, also suggested we had a problem."
The 100-cow herd is housed at night after calving from August onwards and will be inside day and night from October to late March. With so much time spent in cubicles, ensuring the right environment was important for both cow comfort and staff morale, says Mr Court.
The low-slung wooden cubicle shed is sheltered from prevailing winds by a huge feed store, itself sheltered by an earth bank. "Condensation was running down the roof sheets on to cow mats. It made mats damp, leading to skin sores," adds Mr Court.
Having contacted staff at the Farm Energy Centre (FEC), Stoneleigh, Mr Court was given information on ventilation systems and manufacturers. A forced-air system using a 900-watt motor with a 70cm (28in) fan and 40m (135ft) wind sock was chosen for its simplicity after on-farm consultation with a manufacturer. The system cost £720 plus £60 for connection to an electric supply.
Air vents cut into the sock blow fresh air down roof sheets towards slatted side walls. Most air escapes through the bottom end of the cubicle house, taking the ammonia out from slurry slats as it goes.
FECs livestock specialist Stephen Bettany says running costs for this system average 6.14p/hr over a 24-hour period when running at 80% power output. When running fans during Economy 7 hours 12.30pm to 7.30am cost falls to 4.36p/hr.
"After installation and power costs, ventilation systems have few running costs. Fans need to be cleaned at least every six months because as dust builds up it reduces efficiency. But no greasing or oiling should be necessary because most motors have sealed bearings," says Mr Bettany.
The system has been so successful that a similar system was installed in the calf house, using a smaller 648-watt motor with a 60cm (24in) fan and 26m (85ft) airsock. It cost £650 plus £60 for connection. Typical power costs are below 6p/hr over a 24hr period or 3.18p/hr on Economy 7.
"The calf-house system differs slightly because air is directed down on to calves backs and literally blows bugs away. Pneumonia has all but disappeared, saving £10/calf/ year in antibiotic treatment alone. Calves used to look sullen, but are thrifty now," says Mr Court. *
• Cuts ammonia levels.
• Pneumonia reduced.
• Costs 6p/hr to run.