The Relationship between the Specific Gravity of the Green Tibia and its Ash Content in Three-week-Old Chicks

Abstract

During recent years, several modifications in the technique of chick bioassays with vitamin D have been suggested. One of these which has proven to be of value is the use of the toe instead of the tibia (Baird and MacMillan, 1942). This method, according to Campbell and Emslie (1945) should merit wider use as a rapid routine procedure. Another modification is the use of the fresh, rather than the fat-extracted tibia (Fritz and Halloran, 1943). While these methods do not reduce the inherent variability in the ash content of the tibia of the chick, they result in a saving of time.Aubel et al. (1941) reported the mean specific gravity of the humeri and the ash content of the fat-free, dried bones in lots of pigs fed different levels of calcium. The correlation between these two variables was 0.6283 and 0.8741 respectively for experiments 1 and 2.1 Both of these .