Reproduction in Reproduction in PoultryPoultry

Different from Different from mammalsmammals

young are not carried in the hens body

develop inside a fertilized egg outside the hens body

ProcessProcess

begins with male placing the sperm into oviduct of the female

male papillae deposits sperm in cloacal wall of female

ProcessProcess

sperm move up the oviduct to the funnel where the egg is fertilized

sperm cells remain in oviduct 2-3 weeks after mating

ProcessProcess

sperm have full fertilizing ability for about 6 days

after then - ability of sperm to fertilize egg is decreased

Structure and Function of the Reproductive System in Poultry

The reproductive anatomy of poultry differ when compared to that of other animal species.

Male Reproductive System in Poultry

The male poultry anatomy consists of two testes (each with an epididymis and vas deferens) that lead to papillae and a rudimentary copulatory organ.

Male Poultry Reproductive Tract

Unlike other livestock species, the testes of poultry are located within the abdominal cavity along the backbone.

The epididymis, which still functions in sperm storage, is relatively small in relation to the testes.

The vas deferens extend from the epididymis to the cloaca and are located on each side of the vertebral column.

The vas deferens extend from the epididymis to the cloaca and are located on each side of the vertebral column.

The vas deferens function in transportation of sperm and as sperm reservoirs.

Cloaca – the lower end of the avian digestive tract that provides a passageway for products of the urinary, digestive, and reproductive tracts.

Papillae – located at the end of the vas deferens and on the floor of the cloaca, the papillae emit semen into the cloaca of the female.

Phallus – a rudimentary copulatory organ that becomes engorged with lymph during mating, which allows semen to be deposited onto the female’s everted cloacus; the phallus is more developed in ducks and geese.

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Androgen – the male sex hormone produced by the testes.

Functions of androgen include:

• Directing sexual activity and the production of sperm,

• Controlling secondary sexual characteristics of the male, and

• Influencing social rank or “peck order.”

Secondary sexual characteristics of include comb growth, crowing or gobbling, spur development, and male feathering.

Female Reproductive System in Poultry

The functional parts of the female poultry reproductive tract includes one ovary, an oviduct, and the cloaca.

Female Poultry Reproductive Tract

Mature female poultry have only one functional ovary; the right ovary and oviduct degenerate and cease functioning before the bird reaches sexual maturity.

The ovary appears as a cluster of tiny, gray balls that are the oocytes.

At maturity, the ovary contains up to 4,000 tiny oocytes from which ovum may develop over time.

An ovum develops by collecting lipid particles from the blood to form the yolk.

The yolk contains fat for energy and some protein and other nutrients needed by the developing embryo, as well as, a small white dot called the blastodisc that contains the genetic information supplied by the female.

When mature, the yolk is released by the follicle and engulfed by the infundibulum.

The oviduct is about 25 inches long and consists of five parts: the infundibulum, the magnum, the isthmus, the uterus, and the vagina.

Infundibulum – funnel-like part of the oviduct that receives the yolk and is the site of fertilization.

Magnum – second part of the oviduct that secretes the thick white or albumen.

Isthmus – third part of the oviduct that adds the two shell membranes.

Uterus – the fourth part of the oviduct that secretes the thin white, the shell, and the shell pigment.

Vagina – the last part of the oviduct that holds the egg until it is laid.

From the oviduct, the egg passes to the cloaca and then out of the body through the vent at the time of laying.

In addition to producing ova, the ovary produces the female sex hormone, estrogen, and the hormone androgen.

The androgen hormone stimulates comb growth and works with other hormones in egg production.

In poultry, the functions of estrogen include:

• stimulating the growth of the oviduct,

• increasing the size of the cloaca during egg laying,

• modifying feather shape and pigmentation of the female, and

• increasing the level of fat, phosphorus, and calcium in the blood.

D. Describe the poultry reproductive system

Rooster

Testicles

Vas deferensCloaca

Testicles: Produce sperm

Vas Deferens: Carries seminal fluid and sperm from testicles to cloaca

Papilla: The organ in the wall of the cloaca that places the sperm inside the female’s reproductive tract

Hen

Ovary

Magnum

Vagina

CloacaInfundibulum

IsthmusUterus

Ovary: Produces the ovum

Infundibulum: Receives yolk from ovary, where sperm is stored, and fertilization takes place

Magnum: Secretes the thick white of the egg

3 Hours

Isthmus: 2 shell membranes are placed around the yolk and thick white

1 ¼ Hours

Uterus: Thin white and outer shell are added to the egg

20 Hours

Vagina: Completed egg is stored for a short time til laid

Total: 25-27 Hours

1 Infundibulum 4 Uterus2 Magnum 5 Vagina (with egg inside)3 Isthmus

Air

Cell

Yolk

Yolk Membrane

Outer Shell Membrane

Germinal Disc

Thick White

Thin White

Thick White Membrane

Egg Processing Video

Outer Shell

Compare Mammalian and Poultry Reproduction

2 functioning ovaries

2 ovaries, but only LEFT ovary functions

Sperm cells are only viable for a short time after depositing into the female

Sperm cells live for atleast 6 days…and as long as 10-15 days!

Testicles are inside the scrotum on the OUTSIDE of body

Testicles are INSIDE the body cavity

Separate exits for the urinary, digestive, and reproductive tracts

ONE exit from the body (vent)

E. Describe environmental requirements to hatch chicken eggs

Natural:

•Hen lays eggs (1 per day) over period of several days

•When she has an adequate nest, she begins to lay on them to keep them warm

•After 21 days, the eggs hatch

•A hen who is laying on her eggs is referred to as “broody”

E. Describe environmental requirements to hatch chicken eggs

Artificial Incubation:

•Hen lays eggs and they are placed in an incubator

•Incubator keeps eggs at proper temperature and humidity

-Temperature: 102-103 degrees

-Humidity: 60%

•Eggs are turned 2 times daily to prevent embryo from sticking to the inside of the shell

E. Describe environmental requirements to hatch chicken eggs

F. Candle eggs to determine their interior and exterior quality grade.

Grading Exterior Quality:

1-Cleanliness

- Shell should be free of debris or organic

matter

2- Shape

-small end and large end. Not round or oblong

3- Soundness

-No Cracks

F. Candle eggs to determine their interior and exterior quality grade.

Grading Interior Quality:

1- Air Cell

2- Viscosity of Albumen(white)

3- Check for abnormalities

-Blood/Meat Spots

-Cracks or leaks in shell

F. Candle eggs to determine their interior and exterior quality grade.

Egg Quality Grades: AA A B

1/8 inch (Dime) 3/16 inch (Nickel) 3/8 inch (Quarter)

F. Candle eggs to determine their interior and exterior quality grade.

Albumen Viscosity

1-Hold egg up to light2- Twist egg rapidly and watch to see how much the yoke moves

around

Egg Quality Grades:

AA A BLittle movement

Some movement

Lots of movement

F. Candle eggs to determine their interior and exterior quality grade.

LossAny of the following would result

in the egg being graded as a “loss”

-Blood/Meat Spots

-Cracks or leaks in shell

Sperm viabilitySperm viability

10th day - 50% ability19th day - 15% ability

ProcessProcess

after yolk is fertilized it moves through the tract where the rest of the egg is added

egg is laid - embryo grows inside the shell

IncubationIncubation

keeping eggs at the right temperature and humidity for hatching

hen does this by sitting on the eggs

IncubationIncubation

commercial hatcheries use mechanical incubators

incubation of chickens is 21 days

IncubationIncubation

temperature 102 - 103 F. RH - (relative humidity) 60% for the first 18 days

RH 70% for the last 3 days

IncubationIncubation

eggs are turned twice daily for the first 15 days

keeps the embryo from sticking to the inside of the shell

Provide a small amount of oxygen

OviductOviduct

has five partsFunnel - receives the yolk from the ovary

sperm cells received from the rooster are stored here

MagnumMagnum

secretes the thick white of the egg

It takes three hours for the thick white to be placed around the yolk in the magnum

IsthmusIsthmus

the yolk and thick white then moves to the Isthmus

2 shell membranes are added

It takes 1 1/4 hours

UterusUterus

thin white and outer shell are added to the egg in the uterus

egg remains in the uterus about 20 hours

VaginaVagina

after the egg is completed it moves to the vagina

stays in the vagina for a short time and is then expelled from the hens body

One eggOne egg

It takes 25-27 hours for a chicken to produce one egg

OvaryOvary

In the chicken only the left ovary and oviduct function

the ova produced in the ovary develop into egg yolks

Reproductive Reproductive FailuresFailures

general physical condition of animal

has an effect on the agility to reproduce

Reproductive Reproductive FailuresFailures

too fat or too thin may not become pregnant

proper nutrition and exercise can help prevent this

Reproductive Reproductive FailuresFailures

animals in poor physical condition can have trouble giving birth

InfectionsInfections

affect reproductive organssome may prevent pregnancy

others may cause a spontaneous abortion - miscarriage

InfectionsInfections

if animal does become pregnant it may deliver a weak animal which may not live

InfectionInfection

of uterusalmost always fatal to embryo or fetus

HormonesHormones

sexual behavior of animals is regulated by the secretion of hormones

when not properly secreted the animal may not be able to reproduce

HormonesHormones

sometimes animals are treated with injected hormones

CystCyst

swelling containing fluid or semi solid substance

may cause reproduction or breeding problems

may be surgically removed depending on the value of the animal