Abstract
A description is given of an inexpensive metabolism cage, in which powdered diets can be fed without measurable loss.
Coprophagy is completely eliminated in rats fitted with a new design of tail cup, and in this way total collections of faeces and urine are readily achieved. Cups of a similar design have been fitted both to young male and to adult female rats, and use over periods of several weeks has revealed no ill effects. Reproducible estimates of dietary protein quality have been obtained with collection periods as short as 48 to 96 hours, and growth rates are quite good in adequately and uniformly heated rooms.