Effect of dyschondroplasia on the rate of bone growth in the fowl.
A group of Leghorn and a group of broiler chicks were reared from day old. At two weeks old a metallic marker was placed unilaterally in the mid-diaphysis of the femur, tibiotarsus and tarsometatarsus of every chick. After the operation the limbs were radiographed. After a period of growth the birds were killed and the radiographs repeated. Measurements from the radiographs enabled the calculation of the rate of growth at the bone extremities. There were metaphyseal defects indicative of dyschondroplasia present in some of the broiler bone extremities, these bones were considered as a separate group. When the Leghorn and normal broilers were compared there was a significant reduction in the proportion of growth in the proximal tibiotarsus of the broilers. The dyschondroplastic bone extremities in broilers demonstrated a reduction in the proportional growth rate compared with normal extremities.