Relative Utilization of Calcium from Calcium Carbonate and Calcium Gluconate by Chickens

Numerous investigations have indicated that the chicken mav use a number of forms of calcium for its metabolic needs. Workers at the Kentucky Experiment Station studied calcium carbonate, calcium lactate, calcium sulphate, tri-calcium phosphate and calcium chloride as sources of calcium for chickens and found that calcium carbonate was the most effective judged by the degree to which it was utilized in the production of eggs, its influence on the weight of egg contents and shells, and quantity of the salt consumed. Calcium sulphate was not so effective as the carbonate as shown by a smaller egg production and lower weight of shells and egg contents. Calcium lactate was readily utilized but the quantity consumed was variable and small as compared to the carbonate and sulphate. Only small quantities of calcium chloride were consumed and the precipitated tri-calcium phosphate was not a satisfactory source of calcium for egg production as compared to calcium carbonate. The above mentioned salts were fed as supplements to a wheat, yellow corn and skim milk ration. Bethke and his associates state that no difference was found in the availability of calcium in the carbonate, sulfate, lactate and phosphate salts when fed to chicks on a basis of equal calcium intake on a minimum requirement basis. As calcium gluconate is a readily soluble salt, it was thought desirable to study it as a source of calcium as compared to calcium carbonate, since the carbonate is the commonly used source of supplemental calcium for poultry. The following studies include both growing chicks and laying hens. Two groups each consisting of 81 day-old Barred Rock chicks were placed in battery brooders and given rations that differed only as to the source of calcium. Summary. Calcium carbonate and calcium gluconate seem to function with equal efficiency as sources of calcium for the growing chick when equivalent amounts of calcium are supplied. With the laying hen the calcium gluconate seems to function slightly more efficiently than the carbonate, as evidenced by increased egg shell, shell ash, and an increase of calcium in the egg contents.