Involution of bursa of fabricius in male and female chickens: a light microscopic histoquantitative study.

A histoquantitative study of the bursa of Fabricius in 3- and 6-month-old male Prelux Bro chickens (domestic selection) was made. All compartments of normal bursal tissue were examined. At 3 months of age, there were no significant differences in bursal weight and structure between males and females. The only difference observed was the higher volume density of follicular cortex and the lower proportion of follicular medulla in males compared to females. In 6-month-old male and female chickens, a different degree of bursal involution was observed. In the bursa of males, an advanced stage of involution was observed, whereas only the initial signs of bursal involution were found in females.