Many, but not all, kids in 4-H are from family farms. If you do some more research you will find there is a huge difference between family farm practices and factory farming.
More on 4-H here:
Perhaps the word factory farm was incorrect. I live in a farming area, however, and I know full well that the family farms in this area treat animals like a commodity. It is a business. This is not in line with my DD beliefs and therein lies my concern. I am willing to research and keep an open mind, though. There are a few hobby farms where people keep animals because they wish to have a food source where they know where the food comes from - but that is a minority.
And please stopping seen your daughter as someone obsessed and see her as someone passionate.
Support her passion and all the learning she is doing because of it!
FWIW, I am always supportive with my DD's about her interests. I come here to vent because in most cases it is a safe place to do so.
I will be frank and say sometimes I have difficulty telling the difference between a passion and an obsession and what my role is as the parent (as do many others...have you read the numerous "my son is addicted to screens" thread?).
I readily admit that the amount of joy and learning that has come about through guinea pigs is huge, and far, far outweighs any concern I have with her hyperfocus on them. That does not mean I do not have the occasional twinge of anxiety however - I beleive in moderation and balance and her hyperfocus is, well not moderate.
Ah well, she may be more of a specialist whereas I am a generalist. Or she may be a serial specialist - focusing on one speciality after another. In any event it is her way and it is fine.