Detectives said they were in no doubt the attack was linked to the protests against the animal experiments carried out at HLS.
Brian Cass, 53, was attacked by a masked group of three people wielding bats as he returned to his home in St Ives, Cambridgeshire, at about 1950 GMT on Thursday.
Detectives said they were in no doubt the attack was linked to the protests against the animal experiments carried out at HLS.
Mr Cass told the BBC: "You can't afford to give in to these sorts of people. We are very determined, I have always said that we will not give in to terrorism no matter what the situation."
He called for a national police operation to track violent activists down, and urged others involved in animal experiments not to be intimidated by the attack.
"It is important that they are caught before someone else involved in animal research is attacked in this way," he added.
Attacks 'escalating'
Two members of the public who tried to help Mr Cass were sprayed with CS gas before the assailants, one of whom is believed to be a woman, fled.
Mr Cass was taken to hospital where he received stitches to a head wound and was treated for arm injuries. He has since been released.
Detective Inspector Robbie Robertson described the attack as "callous and cowardly".
He added: "In recent months we have witnessed an escalation in the nature of attacks on people and property associated with Huntingdon Life Sciences.
"Last night's events make us more determined to catch those who are responsible for these attacks."
Last month Huntingdon was saved from receivership over a £22.6m loan owed to Royal Bank of Scotland and two US banks, when it was backed by US investment firm Stephens Group.
But animal rights activists have pledged to escalate protest actions against HLS, its customers and its financial backers.