What gas is generated from the anaerobic digestion of animal waste?

The correct answer is - Biogas

Explanation:

Anaerobic digestion of animal waste generates biogas which is a mixture of gases like methane, carbon dioxide, nitrogen, hydrogen, hydrogen sulfide, etc. The primary gas present in biogas is methane which constitutes about 50-75% of total biogas.

Anaerobic or fermentative group of bacteria like methanogens, acetogens, etc acts on animal waste and generates these gases over digestion. This is a natural process that is used by humans to produce methane which acts as fuel that gives energy on burning.

This energy can be used to - generate electricity, cooking, heating, steam production, drying, etc.