The Effect of Feeding Raw Rock Phosphate on the Fluorine Content of the Organs and Tissues of Dairy Cows

Abstract

The influence of fluorine ingestion upon the distribution and storage of fluorine in the animal body has been little studied. This is no doubt due to the fact that adequate quantitative methods for the estimation of fluorine have been wanting, or that available methods were extremely tedious and difficult to use. With the development of methods for the estimation of fluorine the problem becomes a practical one in the study of fluorine metab- olism. The early investigations dealt with the distribution of fluorine in laboratory animals. Little work has been reported on the distribution and storage of fluorine in farm animals. This is of practical importance to man because of its relation to the quantities of fluorine present in meat products, particularly where feeds have been used which contain abnormally high quantities of fluorine. A series of fluorine determinations were made on the tissues and organs of dairy cows fed various levels of raw rock phosphate containing 3.5 per cent fluorine. We wished to follow the distribution of fluorine in the tis- sues of the normal dairy cow; to determine in what tissues fluorine storage took place; and also to determine the influence of fluorine ingestion upon the normal distribution of fluorine in the tissues. The presence of fluorine in the tissues of the animal body has been known for a long time. Knowledge concerning the fluorine content of nor- mal animal tissues and the influence of fluorine ingestion upon the storage of fluorine in the body is quite meager. Gautier and Clausmann (7) have pointed out that fluorine was found by them in all tissues. These investi- gators, Bethke, Kick, Edgington and Wilder (2), Boissevain and Drea (3), as well as others have reported the fluorine content of teeth and bones. Bethke and coworkers reported approximately 0.0409 and 0.0231 per cent fluorine in the femurs of swine. Boissevain and Drea determined fluorine spectrographically in human teeth and reported 0.025 and 0.06 per cent