Comparative Studies of Blood and Uterus Calcium Levels, Alkaline Phosphatase and Carbonic Anhydrase Activities in White Leghorn and White Plymouth Rock Hens, in Relation to Shell Quality and Production Rate

INTRODUCTION VARIOUS workers emphasized the role of one of the two plasma calcium fractions participating in egg-shell formation. Winget et al. (1958) found the protein calcium fraction of plasma decreasing during shell formation while Polin and Sturkie (1957) and Taylor and Hertelendy (1961) pointed out a decline in the diffusible calcium fraction. The latter authors showed a dissociation of the protein bound calcium into the ionic fraction when the first fell by more than 2 mg./100 ml. plasma. Wilcox et al. (1963) reported on positive correlation between the activity of plasma alkaline phosphatase and egg production, but could not state a consistent correlative treand between the enzyme activity in the blood and shell quality in White Leghorn hens. No relationship between the level of alkaline phosphatase activity in the uterus and shell quality was found by Gutowska et al. (1943). Carbonic anhydrase activity in the uterus is regarded to be…