A further study of the effect of sulphanilamide on the metabolism of calcium and phosphorus in the laying hen

Abstract

An experiment has been performed on the effect of sulphanilamide on the calcium and phosphorus metabolism of laying hens.The results showed a decrease in calcium retention and thinner shelled eggs, when sulphanilamide was fed.When the drug was withdrawn the birds took some time to reach normal balance values again, but they immediately produced normally shelled eggs.The results of this experiment, along with a previous experiment, have been considered from other points of view in an attempt to find an explanation of some slightly divergent results. Relationships between calcium retained and calcium in shell and between calcium balance and phosphorus balance have been found and the values for changes in calcium bound to phosphorus and residual calcium in bone have been calculated. These considerations have helped to clear up the discrepancies, and it would appear that sulphanilamide effects may be influenced by season, and by calcium and phosphorus intake.