The effects of calcium, fat and sodium bicarbonate on egg shell strength

Abstract

Five levels of calcium ranging from 2.5 to 4.5 per cent were fed in diets with and without tallow to White Leghorn and Australorp X White Leghorn pullets. Sodium bicarbonate additions to diets varying in calcium and sodium chloride content were fed in two further experiments using Australorp X White Leghorn pullets and hens. Sodium bicarbonate did not increase specific gravity of the egg but did increase liveweight gain. Adding tallow to the diet did not effect calcium utilization. Shell strength increased as the level of calcium increased up to 4.5 per cent. The magnitude of the response to additional calcium was reduced as the birds aged. The results also suggested limestone in the diet depressed the appetite of young pullets but not that of older hens. There were no differences in egg production between any treatments.