I don't see how this would go anywhere after 303 Creative.
Corporations are people for the purposes of free speech thanks to Citizens United. Congress can't pass a law depriving them of their free speech rights - and animal welfare would definitely fall within the scope.
303 says - among other things - that state or federal law can't compel to to perform an act against your right to free speech.
go vegan
Just not an option for most people, and not an appealing option for even more than that.
You don't even need to go vegan to have a positive impact.
Personally, I've been buying a lot more meat alternatives from Impossible, Beyond, Gardein, et al. Had to cut out red meat for heart health, but those alternatives quickly grew on me. The environmental and animal welfare benefits are just a bonus.