Effects of vitamin D3 deficiency on adenosine triphosphatase activity of jejunums from white Leghorn hens.

Supplemental vitamin D3 (D3) was removed from the diet given to an experimental group of White Leghorn hens, at 227 days of age, while a control group continued to receive a supplemental diet. By 14 days after D3 withdrawal, egg weight, egg specific gravity, shell weight, percent shell, shell thickness, and plasma calcium were lower (P less than .05) in the experimental compared to the control group. At 30 to 37 days after D3 withdrawal, experimental hens had less (P less than .05) jejunal adenosine triphosphatase (ATPase) activity than the control hens. The study indicated that lack of D3 supplementation in laying diets reduced jejunal ATPase activity as well as egg shell quality.