The epiphyseal plate closure phenomena for male and female Japanese quail (Coturnix coturnix japonica): histological and biochemical alterations

Abstract

This study was conducted to determine the effect of sex on ossification processes in quail by determining the exact closure timing of the epiphyseal plate in the proximal region of the femur. This was done by investigating the histological and biochemical parameters affecting the osteogenesis process that takes place following quail hatching to observe if any variation existed between males and females in this regard. For this purpose, blood samples were collected from six male and female specimens via IV catheters every week for the first 42 days that followed hatching. The samples were transferred into serum tubes, and PTH (PTH), triiodothyronine (T3), thyroxine (T4), inorganic phosphorus, calcium, and vitamin D values in the samples, which are known to have an impact on ossification, were analyzed. The specimens from which the blood samples were collected were then euthanized, and histological cut-sections that covered the epiphyseal growth plate were collected, along with the bone sections of the proximal regions of the right femur. Considering decalcification, these histological sections were kept in an ethylene diamine tetra acetic acid (EDTA) solution. Routine histological examinations were then conducted on these sections, after which they were embedded in paraffin. Crossman's modified triple staining method was used to prepare them, and Wilcoxon Signed Ranks Test was used to statistically evaluate whether the inspected biochemical parameters played a role in the ossification process of quail and whether a statistical difference existed between sexes in this regard. The findings of our study revealed that poultry animals also have five zones in the epiphyseal plate as do mammals, and they have calcified cartilage areas. The findings also indicate that, while ossification starts to occur both in male and female quail specimens, calcification occurs more frequently in females. It was determined that the proximal epiphyseal plate regions of the femur close at the end of the sixth week in both sexes of quail, although the calcification and ossification are more advanced in some females compared with males.