Animal manure can be very useful. Sheep, goat or rabbit droppings are all great compost activators. Horse manure (not mixed with wood chippings, which is ruinous), stacked up for two or three months under cover, is lovely stuff. The farmer near me allowed me to help myself to cow manure from a huge heap he had. For my troubles I contracted Q Fever from it, which, apart from affecting my long-term health, put paid to my blood-donating days for life in spite of the fact that I'm a rare blood group. If you farm on a large scale I can see the value of human manure, at least several years old, as a soil conditioner, but I can't see why anyone just growing veg in their own back garden would ever want to use it unless they are just trying to prove some obscure point or other. Eat shit. 150,000,000,000 flies can't be wrong.