HISTOLOGY AND HISTOMORPHOMETRY OF THE TIBIAL DIAPHYSEAL GROWTH IN 2 TURKEY STRAINS DURING THE 1ST 6 WEEKS AFTER HATCHING

The comparative cortical growth of the tibio-tarsus was studied during the first six weeks after hatching in two turkey strains, a light and a heavy one. At one day post-hatching the cortical appeared to be con stituted in both strains of an embryonary non-active fibrous bone tiss ue which had completely disappeared at one week. On and after one week the cortice was constituted of a fibrolamellar adult bone tissue elab orated on the periosteal part of the cortex. Its vascular pattern depe nded on the strain and on the thickness of the cortical faces. The his tomorphometrical studies showed that the growth in thickness was earli er and faster in the heavy strain with a Total Diaphyseal Surface twic e larger at 6 weeks but a Diaphyseal Cortical Ratio not significantly different since 3 weeks of age.