Clinical signs and gross lesions

Young chickens, 2 to 5 weeks of age, with vitamin D3 deficiency are unable to stand and have very soft, pliable, legs and beaks. The rib joints are swollen like beads and curved inward. The breastbone often twisted.
In laying birds, vitamin D3 deficiency causes soft-shelled eggs and a drop in production

Treatment and control

Vitamin D3 can be given as treatment, usually in combination with calcium and phosphorus.