Aflatoxin reduces vitamin D absorption and liver damage prevents conversion to the active 25-OH form of vitamin D3. Vitamin C has also been found useful. Although TD occurs in other bones, it is most common at the proximal end of the tibia because of high stress at this point. A higher incidence of breast blisters is usually observed in birds with this condition probably because they are spending more time off their feet. Rickets A direct result of vitamin D deficiency and low or imbalanced calcium or phosphorus nutrition.
Bones are decalcified and weakened causing bowing of the legs and other problems.
The growth plate is increased in width and birds appear sluggish and are reluctant to walk. The bones and beaks are soft and rubbery. Mycotoxins are often involved. Symptoms include swelling of the hock joint, shortening of the leg bone and gastrocnemius tendon slippage off the condyle. This very common ailment in broilers is often confused with other problems.