With the warmer weather here, if they haven’t already done so farmers should service their piggery ventilation systems.

Tim Miller, environmental specialist with Staffordshire-based ARM Buildings, says that this is a much over-looked task. Yet failure to service the system can greatly reduce its efficiency. This unseen problem can result in poorer performance which can cost farmers thousands of pounds annually.

“A common problem is a build-up of meal and dust on the backdraught shutters, though dirt can also accumulate on the fan blades and motors. The extra weight makes the motor work harder meaning more power is needed to open the shutters. Ventilation capacity can be restricted and the system will not work efficiently, especially at lower ventilation rates. Simply cleaning the shutters can improve performance, but many farms do not do this.

“I have been called out to pig units which have never cleaned their fans units at all and, in one case, the build-up of debris actually prevented the back-draught flaps from opening,” he said.

Another area that should be looked at is the wires operating the inlet or outlet flaps. Over time, these stretch and do not give the correct size of aperture. “Producers should make sure that the inlet is closed at 0 per cent and fully open at 100 per cent — the operating range of the inlets. If the cords or pulleys become stretched or broken, the inlets don’t always open as far as they should. In winter the issue is inlets not closing properly,” he said. A simple adjustment usually overcomes the problem.

It is vital to match the inlet opening to the ventilation rate as this will maintain the correct inlet air speed.

Stock-people, quite rightly, focus their attention on the pigs and don’t notice the gradual deterioration in the ventilation system until it becomes a problem. But fans should be checked to see if they are operating as they should in terms of both speed control and on/off function. “You do not want to find there is an issue on the hottest day of the year!”

Recognising this fact, ARM introduced an objective environmental health check for piggeries, which covers all aspects of environmental control and maintenance. This ventilation ‘MOT’ has created a huge amount of interest. “It is not just ‘kicking the tyres’ of the ventilation system that has been useful but the fact that farmers and staff get a bit of training in the correct use of the controls,” said Tim Miller.

“I still get asked ‘What temperature should I run my pigs at?’”