At least 600 healthy pigs have already been culled due to a nationwide labour shortage in abattoirs.
The National Pig Association (NPA) said it was aware of around 600 animals having been destroyed so far, and warned more are expected.
While there has not been a mass cull of pigs yet, such a measure is “the next stage in the process”, says the NPA.
A spokesperson said: “We know of a handful of farmers who have had to cull some pigs (around 600 we are aware of in total).”
The spokesperson said the cull was “hugely difficult” for the pig farmers, and some have even resorted to hiring outside help instead of asking their staff to do it.
“Some are having to use knackermen as they just can’t bear having to do it or ask their staff to do it,” they said.
It comes after farmers warned that up to 120,000 pigs could be culled as the abattoir labour shortage has led to a backlog of pigs ready for slaughter.
Why is there a crisis in pig farming?
Over the past couple of weeks, farmers - in particular the pig farming industry - have been warning that the UK is heading into a welfare disaster that could see a mass cull of over 100,000 animals in the coming days.
The industry has said pigs will have to be killed and incinerated by farmers because of a shortage of abattoir and butchery workers.
The lack of staff is causing a huge backlog of healthy pigs being held back on farms, unable to be sent to abattoirs, and getting too big to be housed.
Rob Mutimer, the chair of NPA, told BBC Radio 4’s Today programme last week the situation is an “absolute travesty.”
Mr Mutimer added that his pigs are usually around 115kg when they go to slaughter, but are now getting up to around 140kg.
“The pens and the sheds and everything just weren’t designed for animals of this size and we’re really heading into an acute welfare disaster very quickly”, he said.