Animal rights activists are expected to continue targeting a Staffordshire farm which was forced to close after a six- year hate campaign.
The family is expected to focus on the arable side of the business.
The owners of Darley Oaks Farm had been breeding guinea pigs for more than 30 years for medical research.
An Animal Liberation Front spokesman said protests were expected to continue until all the guinea pigs had gone.
He said their protests were "outside of the law" but insisted that no lives had been endangered during their campaign.
The owners and people connected with the farm, in Newchurch, have endured years of intimidation including hate mail, malicious phone calls, hoax bombs and arson attacks.
The Hall family announced on Tuesday they would stop breeding the guinea pigs and would close down completely at the end of the year and return to traditional farming.
They said they hoped the decision would prompt the return of the body of their relative Gladys Hammond, whose remains were stolen from her grave in nearby Yoxall in October.
Mrs Hammond, who was buried in St Peter's churchyard seven years ago, was the mother-in-law of Christopher Hall, part-owner of the farm.
Animal Liberation Front (ALF) press officer Robin Webb told BBC News the organisation believed the guinea pigs were being sent to testing centres instead of being re-housed.
'Destroy any equipment'
"When Hillgrove Farm closed RSPCA inspectors worked through the night to collect the cats for re-homing, if this is the intention at Darley then why aren't they closing until the end of the year?" he said.
Hillgrove Farm, in Oxfordshire, was the last establishment in the UK to breed cats for scientific research and testing and closed in 1999 after years of protests by animal rights activists.
Protesters have used graffiti to get their message across
"Until all of the guinea pigs are off the site I would expect ALF activists to continue their protests which, by their very nature, are outside of the law," said Mr Webb.
He said the group's policies were to liberate animals from suffering and damage or destroy any equipment associated with the suffering of animals but denied any involvement in the theft of Mrs Hammond's remains.
"I remain unconvinced that this was an animal rights action," he added.
Sarah Dixon, from Save the Newchurch Guinea Pigs Campaign, said their "peaceful" protests would continue at the site.
"Until the shed where the guinea pigs are kept is bulldozed our peaceful protests will continue, because only then we can be sure that no more animals are being bred for medical research," she added.