Introduction
A condition of chickens, turkeys and ducks seen worldwide and due to Vitamin D or calcium deficiency. Predisposing factors include small body size, high production.
Signs
- Lameness.
- Soft bones and beak.
- Birds go off legs.
- Drop in production.
- Soft-shelled eggs.
- Enlarged hocks.
- Birds rest squatting.
Post-mortem lesions
- Bones soft and rubbery.
- Epiphyses of long bones enlarged.
- Beading and fracture of ribs.
- Beak soft.
- Parathyroids enlarged.
Diagnosis
History, signs, lesions, bone ash. Differentiate from Marek’s disease, spondylitis.
Treatment
Over-correct ration vitamin D, calcium carbonate capsules, place on litter.
Prevention
Supplementation of vitamin D, proper Ca and P levels and ratio, antioxidants. As birds progressively mobilise skeletal calcium for egg production through lay, skeletal size and mineral content at point of lay are critical.