The Effect of Changes in Diet on the Volume and Composition of Rat Milk

Milk from individual stock rats has been analyzed for protein, fat, ash, calcium, phosphorus and magnesium. The effect of changes in the diet of lactating rats has been studied by observing the change in composition of the milk, the number and size of young raised, and the effect of the diet on the mother rat. It is concluded that: Increase in the protein intake results in increased milk yield, but no significant change in the per cent protein in the milk. High calcium diets result in decrease in both milk volume and the percentage of calcium and phosphorus in the milk, with consequent decrease in the total amount of calcium and phosphorus secreted. High phosphorus diets had no demonstrable effect on these milk constituents. Decrease in the intake of yeast decreases the volume of milk, the size of nursing young, and causes severe weight loss in the lactating mothers, without changing significantly the composition of the milk.