equations

Question 1

net energy requirements

Answer 1

-fasting/basal metabolism
-(=heat production in fasted state in thermo-neutral environment)
-measurement using whole body calorimeter
-feeding trial method

Question 2

energy measurement

Answer 2

-burning food, how much heat we get per gram of that material
-comb calorimeter measure this
-some faeces still has energy
-so energy= gross energy of food - energy of faeces