There are currently no places in the US where horses are slaughtered for their meat for human consumption. Oklahoma wants to legalize the slaughter of horses for human consumption, both for EXPORT and within Oklahoma. If merely even the export to other countries is allowed, individuals, corporations and states will drive the PRODUCTION of horses for this purposes. Also horses could be trafficked and sold for EXPORT to countries outside of the US, who DO consume horse meat.

http://www.change.org/petitions/us-congress-and-the-president-of-the-united-states-federal-ban-criminalization-of-horse-meat-export-import-for-consumption