By the time of hatching, the residual yolk sac (RYS) should be
completely internalized into the body cavity of the chick through
the navel, then the navel should be completely closed (healed).
After hatching, the RYS contents are used for general
growth
including growth of the small intestine. The aim of this study was to
verify if there is any effect of navel condition on the growth of
small intestinal villi. Jejunum samples from 200 new hatched
chicks (at the age of 1 up to 5 days), with the average of 20 chicks
per day were obtained, and divided into 2 groups: healed navels and
unhealed navels, which were collected and studied histologically.
For the first time, this study demonstrated the negative effect of
unhealed navel on the growth of small intestinal villi. The results of
this study also demonstrated by Morphometric Parameters
Measurements of small intestinal villi that the high and the surface
areas of villi were increased in healed navel chicks in comparison
with unhealed chicks.
