I want to compare food consumption between three treatment groups. Each treatment group had 20 individuals, however, due to logistical constraints they were group housed in cages with 2-3 individuals per cage. I have information on the average mass of each individual, but the food consumption information is per cage. What is the best way to compare food consumption?
If I assign the average food consumption per cage to each individual, this is making the assumption that all individuals ate equal portions. If I treat cage as the experimental unit, I lose information on the number of individuals per cage, and individual mass, etc.
What is the best way to analyze this data without loosing information or making assumptions? Would it be acceptable to assign a weighted food consumption proportion to each individual? e.g. if individual A is 20 grams and individual B is 30 grams, and total cage food consumption is 100g, then assign A a food consumption value of 40 grams and B a food consumption value of 60 g?