Preservation of Fertility in Male and Female Rats on a Supplemented Milk Diet

Abstract

This work is the outgrowth of the studies made by the authors on the relation of iron and copper to nutritional anemia and hemoglobin synthesis. It is well known that cow's milk is inadequate for the normal maintenance of the rat. Additions of copper and iron salts to an exclusive milk diet protect animals from nutritional anemia and produce an apparent well being in the animals of the first generation from the standpoint of hemoglobin formation, growth, and reproduction. Underhill, Orten, Mugrage, and Lewis 1 have observed no abnormalities in the organs of rats fed milk, copper, and iron for periods of more than a year. Waddell 2 reported sterility in males of the first generation receiving a milk, copper, and iron diet. The sterility was marked by a progressive testicular degeneration together with an absence of motile sperm in the seminal fluid. Ferric chloride, when added to the ration, was found to produce symptoms of sterility as early as 10 weeks after administration. Keil, Keil, and Nelson 3 found the animals on a milk, copper, and iron ration grow more slowly than those on a good stock diet. Reproduction occurred in animals of the first generation, but the second generation did not reproduce. Our results on second generation rats, together with the findings of Waddell, led us to investigate both males and females of the first and second generations in order to ascertain whether or not the sterility on this diet could be ascribed to degeneration of sex organs.

All of the animals (rats) were fed whole milk obtained from Holstein cows in the dairy herd at Iowa State College. The milk was collected directly into glass jugs, in order to avoid contmination with inorganic substances.