"Cows have a living soul and conscience. We really want to help comfort them.
"We have to arrange and give two weeks notice for when we are going to be on site.
"When we arrive usually at about 8am, we gather outside the slaughterhouse on days when the abattoir is operational for about three hours.
"We then stop each of the trucks and are given two minutes to say the last goodbye's before they go and get a bolt gun put through their head.
"We whisper phrases to them like 'we're sorry', 'we see you' and 'I love you'.
Ms Aherne said she believed the peaceful protests are the best way to spread the message about veganism and animal welfare.
She added: "Any social movements have different kinds of action and a lot of vegan groups resort to violence.
"But we condone this and the best way is to peacefully spread the message.
Foyle Food Group has nine sites across the UK where they slaughter and debone more than 7,500 cattle each week across its processing plants.
The company were approached to comment.