Avian Production Management

OVARY AND OVIDUCT 

Ovary

• At the time of embryonic development, two ovaries and two oviducts exist, but only the left ovary and oviduct are functional at hatching, the right atrophies
• The left ovary is situated at dorsal part of abdominal cavity and the fore end of kidneys
• The ovary is responsible for the formation of yolk only

Oviduct

• The oviduct is a long zig zag tube consisting of glandular and muscular parts . Oviduct extends from the ovary to the cloaca. It has 5 distinct parts, viz. infundibulum (9cm), magnum (33cm), isthmus (10cm), uterus (10-12cm) and vagina (12cm)
• Infundibulum is the funnel-shaped, anterior portion of the oviduct, and measures about 9 cm in the laying hens. The mature ovum immediately after release from the graffian follicle, is engulfed by the infundibulum, and remains there for about 18 minutes before moving to the magnum
• Magnum, about 33 cm in the laying hens is the largest portion and albumen-secreting region of the oviduct. The ovum remains in the magnum for about 2 hrs and 54 min
• The ovum stays in isthmus for about 1 hour and 14 minutes. Shell membranes are secreted and egg gets its shape in this region 
• Uterus, also known as shell gland, is a pouch-like structure and the ovum stays here for about 20 hours and 40 minutes in the uterus
• Vagina is the terminal portion of the oviduct having a muscular sphincter at the utero-vaginal junction which helps in expelling the egg during oviposition