The significance of the ash content of the third metacarpal bone for the diagnosis of Ca deficiency in the pig.

A method based on determination of the ash content and the length of the third metacarpal bone as an aid to diagnosis of calcium deficiency in pigs is presented. The material consisted of 58 Finnish pigs of normal slaughter weight, divided according to the mineral content of the diet into 6 groups. The Ca level in the feed varied from 0.8% to 2.2%. The ash contents and lengths of the thirds metacarpal bones of the pigs were compared, and their relationships to a straight line representing the relationship between ash content and length of the third metacarpal bone of pigs receiving a feed with a Ca content of 1.2% and a P content of 1.0% were examined. In the pigs studied the mineralization of the skeleton (Mc III) was influenced by the Ca content of the feed. The straight line defined in the previous paragraph separated the pigs which had received a feed with a sufficient Ca content from those which had received a feed low in Ca. Individual differences in ability to utilize the feed and the osteoporosis induced by inactivity were noticeable sources of deviation from this relationship.