Natural Animal Manures/Fertilisers are widely used in Organic Gardening Circles, they are relatively inexpensive and kind to the soil and our environment.
However care still needs to be taken when using certain Manures around plants particularly if it is fresh, burning can be an issue with some of these brews.
I have been asked before regarding which is the best to use. A real simple rule of thumb is the smaller the animal the manure came from the stronger the manure is, ie Chicken manure is the strongest manure around, its Ammonia content is very high, this is the ingredient responsible for the burning that can occur when fresh Chicken manure is used.
A way around this is to use processed Chicken manure ie the pellitised form you find at the local Garden Centre or Hardware Store it is much safer but care still needs to be taken, make sure none ends up against the trunk of plant you are feeding.
The other end of the spectrum is Cow manure a real safe all be it some what low on nutrient compared to Chicken manure, however it can be applied with gay abandon with little fear of burning.
It is great for building Organic matter in your soil and large amounts can be used and plants planted straight away without any deaths.
So there you go the bigger the Animal the safer the Poop!
Be Happy,
Barry