Reproduction in Poultry
H
AVE YOU EVER wondered which came first,
the chicken or the egg? Either way,
knowing the process of poultry reproduction
and the anatomical parts involved is important. For the world to consume chicken and
even eggs, producers must maintain excellence in the poultry reproductive process.
Explore this E-unit to learn about poultry
reproduction.
Objective:
þ
Identify and describe the male and female reproductive organs in poultry.
Key Terms:
Ñ
cloaca
funnel
isthmus
magnum
papilla
uterus
vagina
Poultry Reproductive Organs
Of all the organ systems within species, the only one that is different between genders of
the same species is the reproductive system. With only a few exceptions, the male and female
reproductive systems in poultry are similar to those found in mammals. For example, the male
reproductive system of poultry includes the testicles, just as the male reproductive systems of
mammals, but they are held within the body cavity instead of within a scrotum.
We will use the chicken as our example as we examine the poultry reproductive system. The
same basic principles apply to all poultry.
The reproductive system of a male chicken, or rooster, includes testicles that produce the
sperm and seminal fluid necessary for reproduction. In this system, the vas deferens carries the
seminal fluid and sperm cells to the cloaca. The cloaca is an enlarged part where the large
intestine joins the end of the alimentary canal. The alimentary canal is the food-carrying pasE-unit: Reproduction in Poultry
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Testicles
Vas deferens
Cloaca
Kidneys
Rectum
Ureters
Intestine
FIGURE 1. The reproductive organs of a male chicken.
sage that begins at the mouth and ends at the vent. The papilla is the organ in the wall of the
cloaca that puts the sperm cells into the hen’s reproductive tract.
UNDER INVESTIGATION…
LAB CONNECTION: The Chicken Egg
During this lab connection, you will be exploring the chicken egg. Materials and tools needed
to complete this lab are an egg, a small bowl, forceps, a dissecting needle, and some paper
towels for cleanup.
Lay the egg on its side in the bowl and softly tap the side of the egg with the dissecting needle. You should be able to slowly chip a small hole in the shell. Work outward from the hole. Use
the forceps to break away larger pieces as you proceed through the lab. As you chip away pieces
of the shell, observe the thin, white membrane just inside the shell. Once the hole in the shell
becomes large enough for the contents of the egg to be poured into the bowl, move ahead with
caution. Examine the interior of the shell, the membranes around the yolk and the white, and
the ways these components work together in poultry reproduction. Try to identify all components
and think about how they relate to egg development within the hen.
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Ovary
Follicles
Magnum
Mature ovum
Funnel (infudibulum)
Isthmus
Uterus (shell gland)
Vagina
Cloaca
Rectum
Rudiment of oviduct
Intestine
FIGURE 2. The reproductive organs of a female chicken.
The reproductive system of a female chicken, or hen, like the reproductive systems of
female mammals, contains two ovaries and two oviducts. However, the right ovary and oviduct
do not fully develop and do not function. The left ovary and oviduct produce eggs. The ova,
produced in the ovary, develop into egg yolks.
The functional oviduct is divided into five parts: the funnel, the magnum, the isthmus, the
uterus, and the vagina.
The first part, the funnel, or infundibulum, receives the egg yolks just produced in the
ovary. The sperm cells that the female chicken receives from the male are stored here.
Another part of the oviduct is the magnum, which secretes the thick egg white. About
three hours are needed for this thick egg white to be placed around the yolk in the magnum.
The yolk and the thick white move from the magnum into the isthmus, where two shell
membranes are placed around the yolk and the thick white. This process takes little more than
one hour.
The longest stage of egg development occurs when the egg remains in the uterus for 20
hours. There, the thin white and the outer shell are added to the egg.
From the uterus, the egg moves into the last functional part of the oviduct, the vagina.
The egg stays there only a short time before it is laid.
This whole process of producing one egg takes the chicken 25 to 27 hours.
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Summary:
2
Reproduction in poultry differs from reproduction in mammals, yet the differences
are small. The reproductive system of a rooster includes testicles housed inside the
body cavity instead of inside a scrotum. Other important parts of the male reproductive system are the vas deferens, the cloaca, the papilla. The female reproductive
system houses two ovaries and two oviducts, but only the left ovary and oviduct
produce eggs. The oviduct of the hen is composed of the funnel, the isthmus, the
magnum, the uterus, and the vagina.
Checking Your Knowledge:
´
1. List five parts of the male poultry reproductive system.
2. Which ovary and oviduct are functional in female poultry?
3. List five parts of the functional oviduct in poultry.
4. Where on its journey down the oviduct does the egg remain the longest?
5. How long does it take a chicken to produce one egg?
Expanding Your Knowledge:
L
Take a field trip to a local poultry farm. In what ways do the producers study the
poultry reproductive process? Do they need to maintain health and management
standards for essential egg development? During your visit to the farm, be sure to
interview the producers or managers to discover what makes their job difficult?
Also, what type of education does one need to maintain this farm? Or what skills
should one obtain? After your interview and field trip, write a one-page report
detailing the answers and revealing interesting tidbits you discovered about poultry
reproduction and careers encompassing it.
Web Links:
:
Learning Reproduction in Farm Animals
http://www.ansi.okstate.edu/course/3443/study/Notes/poultry/index.htm
Poultry: Reproduction and Incubation
http://msucares.com/poultry/reproductions/index.html
The American Egg Board
http://www.aeb.org/
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