I do not understand the purpose of your question. We do know that in (moist) excreta there is degradation of nitrogen containing substances with ammonia being the (main) end product. The best precaution is keeping the litter dry.

Given the huge surface of the excreta in a poultry house any other (directly animal related) source will be of minor importance.

So, are you looking for a theoretical answer or for something practical?

Dear Nadir

The formation of ammonia came mainly from uric acid and the litter pH affect on the amount of released ammonia to the air of poultry house, hence the pH below 7 the ammonia become low in the air of the house but with the increase of the pH in the litter above 8 the ammonia concentration become high in the air.

Good Luck

 Dear C.A. Kees Kan

In an experiment we are conducting in the laboratory of ammonia, we found, after transfer of hens in metabolic cages or do not exist excreta and litter, There are traces of ammonia in the atmosphere .

Maybe it comes from releases from the cloaca ?

Dear Nadir

It might well be that the hens do excrete some ammonia (by the cloaca). Another possibility is the presence of faeces and urine on the feathers and skin around the cloaca, on their breast and on the legs and feet of the animals. These will also decompose and give rise to ammonia formation 

I have however serious doubts that these possibilities will have a significant contribution to the total amount of ammonia present in a poultry house with a layer of composting manure being present.

Traces of ammonia in metabolic cages can come from soiled feet, feathers and cloaca with litter in which there is  degradation of nitrogen substances. i

Thank you very much  for replies !

By looking at ammonia's chemical composition, NH3, we can make intelligent guess where that little ammonia comes from

Apart from the action of microbial urease on faeces, due to the microbes present or moves up towards the digestive tract. These microbes converts undigested protein/amino acids and endogenous N compounds into various other products including NH3. So, this trace of ammonia may be due to the microbial action on endogenous N (since there was no faeces).  

Ammonia is used to make fertilizers, fibers, plastics and explosives. It is also used in cleaning products and food additives, so in addition to the faeces, it may be possible to find ammonia in the environment.

Dear Nadir

As you, yourself said the major attempts are focused of the "concerning level" of ammonia and in my knowledge nobody could eliminate the ammonia in breeding saloons, completely, specially in large houses. As mentioned above, ammonia originates from different sources which could be divided to management and non-management sources.

So because of this wide range of origin, ammonia could hardly eliminated (becomes 0) and if its elimination was possible in rare cases, this situation would be temporary and with small changes such as environmental modifications, some little ammonia could produce.

But I think we could find no animal science researcher who do not know at least one possible way to reducing the ammonia from its concerning level.

As a conclusion, various sources of ammonia make its complete elimination from the atmosphere of poultry houses very hard (near to impossible) and non-economical. However some ways to lowering ammonia depends on situation, could be consider as best.

As I had understood, you do not need new references.

Good Luke!

They are basically two sources of ammonia in a poultry house:

1. Nutrient metabolism especially when the feed is rich in proteins. This releases a lot of uric acid, which is of course combined with excreta when it is being egested from cloaca. When excreta/uric acid combination decomposes/ferments ammonia is released.

2. Waste feed and water due to wrong/poor design of feeders/drinkers. When these wastes are allowed to accumulate in the house, they decompose/ferment, releasing ammonia.