If you had permission might be good to post near the dead animals and just sit...If they are feeding you can legally hunt bait piles.. The piles would be the attractant.. If I was going to call I would be just a couple of Howls (Interrogation) and just remain quiet for a long period of time.. You could also do some KIYI for a minute and remain quiet for awhile and lastly..The coyote pup. I would think if you stick to those three coyote vocalization and do it limited too.. Why use food sounds if there is dead horses all ready available for them to eat.. You want to get the coyotes in the area upset that other coyotes are moving in..The sounds I recommended will do that...
Any of your scent blowing toward the dead animals would hurt your hunt...If the coyotes are there feeding...