So after a bit of consultation with my boss (by email) and the dangling of publication carrots regarding yesterday's email, she and I came to a compromise in which I would breed the animals, with the concession that the colleague would have to aid me in the work but not need to do any of the handling.
When informed of this decision by email, this colleague refused to provide this aid. His reply also excluded our boss. Her response was that she was gobsmacked and will talk to him in person on Monday.
I'm looking forward to this!