Four primary ways in which we have conceptualized moral and legal obligations to nonhuman animals.
1. Prior to the 19th century animals are regarded as things both in moral theory and under the law. Consequently neither use nor treatment of animals matter as animals don't "matter" morally or legally.
2. The animal welfare position became popular in the 19th century (this is the continuing paradigm today)--this separates USE from TREATMENT. In this view USE is acceptable and the only concern is TREATMENT. This view holds that we have a moral and legal obligation to treat animals "humanely", ie, avoid imposing unnecessary suffering. This is primarily a view concerned with REGULATION of animal treatment.
3. The animal rights position is that USE cannot be justified and seeks to abolish all animal use. This rejects the theory of regulation--"humane" treatment is irrelevant if USE is morally wrong. Also claims that regulation does not sufficiently protect animal interests and actually encourages social acceptance of USE.
4. The "new welfarist" position (various manifestations) is critical of the laxity of prior welfare positions and simply wishes to magnify the regulations approach applied to industrial farming.
It seems that of these four--only the third represents a radical shift in our perceptions of moral obligations. In fact, welfarist positions retain a primarily "property" position--a kind of patriarchy of protection.