When you say "muckheap", it brings to my mind a picture of a pile too wet for aerobic decomposition to take place. Make sure and layer your wet, "mucky" ingredients between buffers of dry, fibrous ingredients to ensure proper airflow and expedient breakdown. You want the pile to be damp throughout, but not sopping. After it's gone through a heat (3-6 months), you can turn it, re-moisten and let it compost again for a more refined product, or chunk it through a spreader and onto your fields as is; the initial heat is enough to alleviate most problems caused by the application of raw manure, though I would only use thoroughly finished product in the dressing of crops grown for human consumption.