March 23, 2021

 
ARM Buildings: Overweight pigs put pressure on ventilation systems

Overweight finishing pigs — rolled over due to COVID-19 disruptions of slaughter lines — have put pressure on ventilation systems and turned the heat up on pig farmers, said Tim Miller, an environmental specialist at ARM Buildings.

The extra liveweight has raised piggery temperatures enough to cause fans on some units to operate at levels not normally seen until late spring or summer, potentially catching out systems that have not been maintained properly, Miller highlighted.

Pigs nearing slaughter at 110kg liveweight produce about 200W of heat each, equivalent to 100 single bars of an electric fire in a typical 500-pig house. However, when held over for a week or so, as has happened recently, they can put on as much as an extra 10 kg apiece – 5,000 kg. "This will produce up to 9kW of extra heat which means piggeries will exceed set temperature even quicker, causing fans to work flatout for extended periods of time," Miller explained.

"In some piggeries, individual fans can remain idle for months if not linked to a sequencing system, such as that offered by Dicam. If they don't work when needed, there can be serious problems," he said. "When a house is at maximum stocking density, full ventilation capacity is needed, and this is when routine servicing pays dividends."

Miller pointed out that, according to Defra figures – assuming a 75% killing-out percentage – average UK liveweight of finished pigs leaving farms in January jumped from 115.0kg to 120.9kg. "I have been on farms where pigs have been as heavy as 130kg before farmers could send them to slaughter," he said.

- ARM Buildings