Feed Conversion Efficiency
To estimate an organisms total growth efficiency you need to know the complete feed ingestion from birth till death, the complete cellular metabolism and the total amount of feces released.
The energy used to stay alive without any growth is called energy used for maintenance.
An approximation can be made using respiration and calculations of metabolism
Where
Units used for calculating the growth efficiency of an organism are joules, which is the
Metabolism can be estimated via the respiration of an organism