I would think both--it will attract coyotes and, depending on how much and how well you hunt and trap, reduce the population. At some point hunting and trapping will reach a balance point with the population. Either you wipe them out temporarily, or a lesser number of wised up coyotes become very wary of traps and bait there. That will help by making them reluctant to hang around there--temporarily.

I suspect the calf killers are the dominant pair that have that farm staked out as their territory. If you get them, it will be a while before the problem arises again. Not all coyotes kill livestock. But after one dominant pair or experienced calf killer leaves, another will sooner or later replace them around cattle farms.

It is more work and problem to provide newborn calves with a coyote--safe compound until they are better able to fend for themselves, but that is the best solution. Not as much fun though...

He buries his dead animals like a respectable farmer Helping keep rabies and other diseases down. Bait cannot be seen from air, that's basically the only rule in Pa regarding hunting or trapping over bait.

You'd be surprised how far a coyote will dig down for something that's buried. I'd personally go check out where he's buried them in the past. Set the trails coming to it as far out as your state law dictates. I knew of a pig farmer that had a "compost pile" or a pile he'd bury his pigs. They'd dig down and carry off a full hog every night no matter how deep he buried it.