A simple search  on the internet gave this informative document by the FAO

http://www.fao.org/docrep/013/al715e/al715e00.pdf

There are many ways of managing poultry litter.

1 Direct land application (this is common application)

2 Composting option ( I am sending my  recent publication -review paper)

3 Biogas process (It can be co-fermented with other materials or alone to produce heat electricity and manure etc..)

4. Biogas process plus composting

5. Incineration to directly produce energy

6. Gasification

Article Composting Broiler Litter

Thanks for the answer

Worth reading

A Practical Guide for Composting Poultry Litterhttps://www.researchgate.net/post/What_are_the_possible_ways_to_treat_poultry_litter_wastes 

You could dry poultry litter, mix it with maize bran in the ratio of 3:1 (litter, 3kg: maize bran, 1 kg). This mixture is a very good feed for pigs (FOR THOSE WHO KEEP this type of animal anyway!)

thanks a lot Sir