Throwing in a big bag of grass clippings from the lawn is sure easier and free! They distribute it themselves and it gets cleared out and composted weekly with the next cut.
Sorry for your loss. Need more details. Question is, are predators getting into the coop or into your yard as they free range. If the yard, its obvious that you need to build a proper hardware protected run. If the coop, how are they getting in and have you electrified it?