If you or someone you intend to provide it to eats it, then it falls under the commonsense definition of "food." Satanism is based on commonsense, not strict laws.
I would personally even be so liberal as to interpret the Tenth Rule to be inclusive of any case in which killing an animal is needed for your own survival or the survival of others, besides the two specific examples it gives. If you MUST kill an animal to stave off cold, for example, or the animal is reasonably considered a menace (a rabid dog whether it attacks me or not, I will put down on sight to prevent harm to children it may bite and to stop the spread of infection to other animals).
The rule is best viewed as an injunction against wasting the lives of animals needlessly, as we view such wanton destructiveness as counter to the natural order.
Again, use common sense.
Oh, and if your job bothers you - get a new one. Some folks don't mind the dirty work of slaughter, some couldn't stomach a minute of it. All in what you can deal with.
"The devil I'll bring you," answered Hagen. "I have enough to carry with my shield and breastplate; my helm is bright, the sword is in my hand, therefore I bring you naught."