Effects of long-term supplementation of laying hens with high concentrations of cholecalciferol on performance and 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. 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. The objective of this research is 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 1 of 5 experimental diets for 40 wk: 1) control (contained 2,200 IU of D3/kg of diet), 2) control + 7,500 IU of D3/kg of diet (9,700 IU of D3/kg of diet total), 3) control + 15,000 IU of D3/kg of diet (17,200 IU of D3/kg of diet total), 4) control + 22,500 IU of D3/kg of diet (24,700 IU of D3/kg of diet total), and 5) control + 100,000 IU of D3/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 predetermined points throughout the 40-wk period (19 to 58 wk of bird age) for assessment of egg weight, egg component weights, Haugh unit, yolk color score, specific gravity, egg mass, and feed efficiency. There were no consistent differences among the dietary treatments over the experimental period. Hens supplemented with up to 102,200 IU of D3/kg of diet resulted in no significant reductions in egg production, feed intake, feed efficiency, egg component weights, yolk color, Haugh units, and specific gravity in comparison with the control-fed hens (P > 0.05). These data suggest the addition of cholecalciferol to the diet of the laying hen at concentrations up to 102,200 IU of D3/kg of diet had no consistent negative effects on laying hen performance or egg quality.