Relation of Food Consumption of Milk-fed Rats to the Growth of the Suckling Young.

Abstract

In a recent investigation 1 it was pointed out that the failure of milk fed rats to successfully suckle their young is not due primarily to a deficiency of the antineuritic vitamin in the milk secretion as has been suggested by a number of investigators, 2 but to the inability of the particular rat to ingest enough milk to meet the lactation requirements. In this investigation the mother animals were transferred from the stock ration to the milk diets just previous to or immediately following parturition.

In order to rule out the possible criticism that the results in this previous investigation were vitiated by a carry over of the antineuritic vitamin from the prelactation period when the animals were receiving high vitamin diets, we have fed groups of rats from infancy (4 weeks) both evaporated milk, which has been shown to be lower in the antineuritic vitamin than quickly boiled milk, and dried partially skimmed milk supplemented with butter fat to make it comparable to the evaporated milk. Certain of these groups were given a concentrated alcoholic extract of wheat embryo, calcium phosphate, and viosterol, either singly or together, while others received the milks without these additions. Small amounts of copper, iron, and iodine were added to all diets.

The females in all groups bore young. Shortly after birth the number in the litter was reduced to 6. In some cases the number born was less than 6 or the young died during the first days following parturition, so that there was some variation in the number raised. The food ingestion was measured throughout the lactation period (21 days) and the caloric ingestion evaluated in relation to the body weight of the mother.