Well, that’s an extremly complex questions and there are many cases to consider and personal opinion on these can vary a lot.
For example one of the least limited cases should be animal testing for medical purposes. There should still be limits, but they have to be carefully decided by weighing the potential benefits against the suffering caused.
Another prominented case would be factory farming. I think that’s quite bad and also makes for a poorer end product. But I don’t think there is anything fundamentally wrong with keeping livestock for eating it. But the details of how regulation should work exactly are again quite complex and beyond the scope of a lemmy comment.