Agriculture Reference
In-Depth Information
The Reproductive System
We see two types of reproduction in the animal world: asexual and sexual. All poultry
species are sexual reproducers, which means production of a new individual requires
the union of male and female sex cells. The reproductive organs in poultry consist of
the
testes
in the male, and
ovary
and
oviduct
in the female. Birds differ from mammals
in that the egg has a hard shell and must be
incubated
(warmed and nurtured) outside
of the parent's body. The egg contains all the necessary elements to support life during
embryonic development. A strong shell protects the contents of the egg and the devel-
oping
embryo
. The female bird is unique in the animal world in that it develops only
one functional ovary and oviduct; most other animals have two.
WAIT BEFORE THEY MATE
In the late nineteenth and early twentieth century, it was common practice to purchase
turkey hens that had been bred and would soon lay an entire clutch of fertile eggs.
Buyers did not purchase a male, only bred hens. They relied on the seller to make
sure the hen was bred.
The male's sperm live in the female's body for roughly 20 days. However, the
length of time a hen remains fertile from one mating can vary greatly from breed to
breed and bird to bird. This is also a key factor in determining how long you must
have a new mating together before you begin saving eggs for setting. If you aren't
sure of the length of fertility, you run the risk of having no proper record of your
breeding lines; you won't know who the new chicks' father is.
Three weeks is a safe waiting period to be sure of getting eggs from the pairing
you desire. With turkey hens, however, you should make sure before collecting eggs
that they have mated with the new male if you want to guarantee purity. Turkey hens
can be very particular about who they mate with and may shun your choice of a new
mate for them.
In Males
The testes of the male are paired but, unlike those of most mammals, are located intern-
ally, near the tip of the kidneys. This means that the sperm is produced at body tem-
perature, not a degree or two lower as is the case in most mammals. Relative to body
size, the testes are much larger in birds than in mammals. In chickens, they constitute
about 1 percent of the body weight. The testes also increase in size during the breeding
season and decrease in the nonbreeding season. This is particularly evident in geese and
