Stop Craddock Farms spokeswoman Deirdre Sims said the activists entered the Pukekohe farm with straw and silverbeet for the hens, and vegan sausage rolls for the workers.
She said caged hens were deprived of straw to scratch and nest in, and did not get anything green or fresh to eat.
The group did not have permission but arrived "peacefully", she said.
"It was a symbolic action. Our plan was to peacefully leave these gifts there, speak to the farm owners Dwight and Stefan [Craddock] about our intentions and then leave."
Ms Sims said unfortunately things quickly got violent. She alleged the men grabbed protesters, threw rocks at their cars and made verbal threats.
She said their behaviour had left activists "shaken".
"We were very peaceful and we were just there symbolically to carry out our action. We want to see a ban on all cages.
"Obviously we had good intentions and they just became very angry and we were really not expecting that at all."
She said she would like to sit down with the men and have a "proper conversation" about what they wanted, and why.
"Given the attitude from them I don't think that's a possibility which is a real shame."
Ms Sims said despite the "violent behaviour" activists were committed to continuing with their cause.
"We want to do what we can to stop them from building this new mega-factory farm, because it will be the biggest in the country, and if they do build it, it will entrench cages as the future of egg farming in our country, which we really don't want."
Craddock Farms managing director Stefan Craddock ridiculed the allegations.
"The allegations made by the protesters are laughable, ridiculous and totally untrue," he said.
"The protest today was unexpected and brief, lasting no longer than 10 minutes, and while we believe people have a right to express their opinion, we do object to trespassing on private property.
"We spoke with the protesters, there was a discussion about a camera, we urged them to leave and they did so shortly after.
"The only notable occurrence was the protesters dumping a pile of propaganda, straw and silverbeet leaves on the driveway."
Mr Craddock said neither of the pair on-site this morning were aware of any of the alleged incidents detailed by the activists "so as far as we know, they are all completely untrue".
He said police had been notified of the trespass.
