New data suggest that the addition of cholecalciferol to the diet of the laying hen at concentrations up to 102,200 international units (IU) of vitamin D3 per kg of diet had no consistent negative effects on laying hen performance or egg quality.

There is current interest in increasing human vitamin D dietary intake without having to modify human eating habits. One method to increase human dietary vitamin D intake is to generate eggs with increased concentrations of vitamin D through high-concentration vitamin D feeding in the diets of laying hens, according to M.E. Persia and colleagues in a paper published in Poultry Science.

They highlighted that although eggs can be produced with high concentrations of vitamin D, the consequences of these diets on hen performance and egg quality have not been validated and so the objective of their research was to quantify the effects of high concentrations of cholecalciferol (D3) on laying hen performance and egg quality.

Hy-Line W36 laying hens were placed on one of five experimental diets for 40 weeks:

• control (contained 2,200 IU of D3 per kg of diet)
• control + 7,500 IU of D3 per kg of diet (9,700 IU of D3/kg of diet total)
• control + 15,000 IU of D3 per kg of diet (17,200 IU of D3/kg of diet total)
• control + 22,500 IU of D3 per kg of diet (24,700 IU of D3/kg of diet total), and
• control + 100,000 IU of D3 per kg of diet (102,200 IU of D3/kg of diet total).

Egg production and hen mortality were monitored daily. Feed intake was determined weekly. Eggs were collected at pre-determined points throughout the 40-week period (19 to 58 weeks of bird age) for assessment of egg weight, egg component weights, Haugh unit, yolk colour score, specific gravity, egg mass and feed efficiency.

The researchers found no consistent differences among the dietary treatments over the experimental period. For hens supplemented with up to 102,200IU of D3 per kg of diet, there were no significant reductions in egg production, feed intake, feed efficiency, egg component weights, yolk colour, Haugh units and specific gravity in comparison with the control-fed hens (P>0.05).

Reference

Persia M.E., M. Higgins, T. Wang, D. Trample and E.A. Bobeck. 2013. Effects of long-term supplementation of laying hens with high concentrations of cholecalciferol on performance and egg quality. Poult. Sci. 92(11):2930-2937. doi: 10.3382/ps.2013-03243