For what it’s worth, they and other livestock love mycelium from culinary species like Pleurotus ostreatus. The substrate is healthy myceliated straw/grain with the complex carbs predigested by the fungi and it has immune system benefits for them: openagriculturejournal.com/…/e187433152305260.pdf

My ideal homestead revolves around around multi-tiered green recycling using them. The fungi break down the garden waste that the chickens won’t eat, the unproductive mushroom colonies go to the chickens and pigeon towers, the manure and eggshells go into the vermicomposter and garden. Those mushroom colonies are a major cash crop with a myriad of health benefits depending on what you’re growing.