Published online by Cambridge University Press: 05 September 2013
This review paper delineates how vitamin D3 and its metabolites produce beneficial effects on the performance of both broiler and egg laying chickens. This review provides information on the evaluation of cholecalciferol sources, metabolites, requirements for cholecalciferol in birds, its effect on hatchability of fertile eggs and its impact on immunity. Notable beneficial effects have been seen on body weight gain, feed intake and feed efficiency in both broilers and laying hens. Cholecalciferol can provide beneficial effects on egg quality by increasing egg production, egg and shell weight, and shell strength by increasing thickness. It has a significant effect on the immune system and can help in the suppression of certain autoimmune diseases. The possible mechanisms contributing to these effects and the factors thought to explain the variability in these responses are discussed. Overall, cholecalciferol and its metabolites have been shown to greatly improve the performance of both types of commercial chickens, which can lead to enhanced production and a reduction in feed costs. The authors recommend a modified feeding programme containing higher levels of vitamin D3 supplementation than the NRC (1994) requirements in order to allow for sufficient skeletal growth in the starter and finisher diets of broilers.