2. What source of energy do organisms use if they don't use the sun's energy?

Most likely, the answer is "Other organisms"

Explanation:

For example, we use animals or plants to gain energy (eating)

common management practices in dairy and poultry farming are: (i) proper shelter facilities and their regular cleaning. (ii) some basic hygienic conditions such as clean water, nutritious food, etc. (iii) animals are kept in spacious, airy, and ventilated place.