The Mineral Composition of Young Rats

Publisher Website
Google Scholar
Abstract
Data on ten stock and 135 experimental rats, receiving different levels and ratios of calcium and phosphorus, and 8431 young born to these mothers during eleven consecutive reproductive cycles have been compiled. It is noted that: 1) the rat is relatively cartilagenous at birth; 2) the mineral content of the rat at birth is relatively constant, in spite of wide differences in maternal mineral intake; 3) because of constancy in the composition of the body ash of 21-day-old rats, even when their mothers receive varying mineral intakes, the percentage of calcium and phosphorus in their gross bodies is calculable with fair accuracy from the percentage ash; 4) with the exception of high phosphorus diets, the body ash of sucklings (21 days old) may be used as a measure of bone ash, or calcification; 5) female rats, 21 days old, contain more ash, calcium, and phosphorus than do males of the same age; and 6) during consecutive reproductive cycles the number of young born per litter decreases, but the average weight at weaning increases.