No person, firm, or corporation shall sell, transport, offer for sale or transportation, or receive for transportation, in commerce, any carcasses of species designated by regulations in effect on the day before , or parts of such carcasses, or the meat or meat food products thereof, unless they are plainly and conspicuously marked or labeled or otherwise identified as required by regulations prescribed by the Secretary to show the kinds of animals from which they were derived. When required by the Secretary, with respect to establishments at which inspection is maintained under this subchapter, such animals and their carcasses, parts thereof, meat and meat food products shall be prepared in establishments separate from those in which other amenable species are slaughtered or their carcasses, parts thereof, meat or meat food products are prepared.November 10, 20052005-11-10