This paper is about incineration of sewage sludge. They consider incineration at temperatures like 700C to 900C. Seems like you end up burning 98% of the nitrogen, which is then released as gas (bottom of page 12, just before Conclusions). The output ash only contains 2% if the input nitrogen.

Kind of defeats to point of using the output as fertilizer.

https://sci-hub.se/https://doi.org/10.1021/acs.energyfuels.5...

Cow and horse feces look pretty different from human feces, drier and "herbal", and I would be surprised if they share the same combustive properties.

Sheep/goat/rabbit also seem naturally much drier than human tho I've never investigated their internals :)

Edit: on a second thought, cow shit is not particularly dry

https://en.wikipedia.org/wiki/Dry_dung_fuel: “Dry dung fuel (or dry manure fuel) is animal feces that has been dried in order to be used as a fuel source.”

[1] https://www.amazon.in/Fresh-Cakes-Religious-Purpose-Handmade...

- Burning cow dung cake in your holy function icrease positive energy and kill all bacteria and germs and purify air also .

On the other hand, combustion could also help with destroying the antibiotics found in the manure, which spread to the soil and accumulate in produce.

https://www.susana.org/_resources/documents/default/2-1832-2...

>Complete elimination of pathogens from Human Solid Waste (HSW) is a priority of our biochar reactor. By heating an appropriate flow of input material to high temperatures above 450 C for about 15 minutes, the material thoroughly chars, causing a 100% elimination of pathogens.

Doesn't say anything about heavy metals or pharmaceuticals. In particular I don't know whether heat can denature or destroy birth control hormones like ethinylestradiol. If it's suspended in water, it can be removed through a reverse osmosis or activated charcoal filter. Maybe leaching before charring and filtering the runoff would help? Dunno.