Transcript What are the proper terms used in describing poultry?

CHICK EMBRYOLOGY
WHAT ARE THE PROPER TERMS USED IN
DESCRIBING POULTRY?
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Poultry is the group name for all
domesticated birds used for meat,
eggs, or feathers.
A
baby chicken of either sex is a chick.
 A young male chicken is a cockerel.
 A castrated (neutered) male chicken
is a capon.
 A mature male chicken is a rooster.
 A young female chicken is a pullet.
 A mature female chicken is a hen.
 A group of chickens is a flock.
WHAT ARE THE PROPER TERMS USED IN
DESCRIBING POULTRY?
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A. Chickens are classified as layers or
broilers.
 Layers
are chickens used to produce large
quantities of eggs.
 On
average layer hens produce 250 to 270 eggs per
year.
 Broilers
are six- to
seven-week-old
chickens weighing
about 4 pounds that
are used for meat
because they are tender.
WHAT ARE THE DIFFERENT, BREEDS,
AND VARIETIES OF CHICKENS?
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We have two breeds of chicken in our incubator:
1. The White Leghorn.
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The Leghorn is the most popular layer breed in the United
States.
This breed is also known for its ability to take flight.
Leghorns produce white eggs.
They express yellow skin, yellow shanks, white earlobes, and
reddish-bay eyes.
They are somewhat smaller than most breeds, and tend to be
noisy.
The chicks are white in color.
WHAT ARE THE DIFFERENT, BREEDS,
AND VARIETIES OF CHICKENS?
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2. Rhode Island Red
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The Rhode Island Red is a dual-purpose breed; that is, it is
raised for meat and eggs.
The breed is dark red and lays brown eggs.
Rhode Island Reds have yellow skin, yellow shanks, red
earlobes, and reddish-bay eyes.
Chicks are a light red to tan color with two dark brown bars
running down their backs.
HOW DOES THE PROCESS OF FERTILIZATION TAKE
PLACE IN A CHICKEN EGG?
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The yolk is released into the oviduct (a long, spiraling tube in
the hen's reproductive system), where it can be fertilized
internally (inside the hen) by a sperm.
Fertilization of a chicken egg takes place when the sperm
unites with the egg, forming the blastoderm.
Unfertilized eggs will go through the same process however,
it will form a blastodisc.
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A blastodisc will not be a dark white
Not symmetrically round
Can an un-fertilized egg develop an embryo?
CAN AN UNFERTILIZED EGG ACTUALLY
DEVELOP?
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Parthenogenesis is an inherited trait that
causes the development of unfertilized eggs.
 About
1% of parthenogenetic embryos will develop
and hatch with deformities.
 Parthenogenesis is more common in turkeys than
in chickens.
WHAT ARE THE INTERNAL PARTS OF AN EGG
AND WHAT ARE THEIR FUNCTIONS?
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1. Blastoderm/blastodisc
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2. Yolk: Produced by the hen's ovary in a process called
ovulation.
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It is the yellow, inner part of the egg where the embryo will form.
The yolk contains the food that will nourish the embryo as it grows.
WHAT ARE THE INTERNAL PARTS OF AN EGG AND
WHAT ARE THEIR FUNCTIONS?
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3. Vitelline (yolk) membrane - the membrane that surrounds
the yolk.
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4. Thick albumin - the stringy part of the egg white (albumin)
located nearest the yolk.
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5. Thin albumin - the watery part of the egg white (albumin)
located farthest from the yolk.
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6. Chalaza - a spiral, rope-like strand that anchors the yolk in
the thick egg white. There are two chalazae anchoring each
yolk, one on the top and one on the bottom.
WHAT ARE THE INTERNAL PARTS OF AN EGG
AND WHAT ARE THEIR FUNCTIONS?
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7. Inner shell membrane - the thin membrane located between the
outer shell membrane and the albumin.
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8. Outer shell membrane - the thin membrane located just inside the
shell.
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9. Air cell - an empty space located at the large end of the egg; it is
between the inner and outer shell membranes.
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10. Shell - the hard, protective coating of the egg.
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It is semi-permeable; it lets gas exchange occur, but keeps other substances
from entering the egg.
The shell is made of calcium carbonate.
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Label the Chick Egg
WHAT IS THE IDEAL ENVIRONMENT FOR INCUBATING
EGGS ARTIFICIALLY?
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Four Factors must be present for ideal incubation
conditions:
A. Temperature. Optimum temperature for hatching
chickens is between 99 and 100 degrees F.
B. Humidity. Eggs lose moisture during development
and low humidity causes an increased loss. High
humidity can prevent the correct evaporation of water.
WHAT IS THE IDEAL ENVIRONMENT FOR
INCUBATING EGGS ARTIFICIALLY?
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C. Ventilation. Proper circulation is critical to assure a
fresh supply of oxygen and removal of carbon dioxide.
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D. Position and turning of eggs. The head of the chick
must face the large end of the egg for proper hatching.
Eggs should be incubated large end up, and turned three
to five times daily to prevent the developing embryo from
attaching to the shell membrane.
HOW DO WE PREPARE EGGS FOR HATCHING AND CARE
FOR YOUNG BIRDS DURING BROODING?
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Fertility of eggs can be determined by a process known as
candling.
A. Eggs held up to an egg candler, a device for shining a light
beam into an egg. Eggs will look different depending on
fertilization or lack of fertilization. Fertile eggs will appear
darker as the developing embryo begins to form. Infertile eggs
can be detected after 15 to 18 hours of incubation.
Between the following poultry species, who has
the longest incubation period? Shortest?
WHY?
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Duck
Pigeon
Ostrich
Chicken
Turkey
HOW DO WE PREPARE EGGS FOR HATCHING AND CARE
FOR YOUNG BIRDS DURING BROODING?
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Different breeds of poultry have different
incubation lengths:
Bird:
Incubation:
Chickens
21 days
Ducks/Turkeys
28 days
Pigeon
18 days
Ostrich
42 days
Do not candle or turn the eggs the last three
days of incubation.
WHAT IS THE PROCESS OF CHICK DEVELOPMENT DURING
INCUBATION?
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Day 3:
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Day 6
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Body parts have begun to for
The embryo will have a distinct question mark shape
Heart begins to beat
Voluntary movement begins
formation of reproductive organs and differentiation of sex
Day 9
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Egg tooth begins to form
Body parts can be clearly recognized
WHAT IS THE PROCESS OF CHICK DEVELOPMENT DURING
INCUBATION?
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Day 12
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Day 16
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Beginning of feathers
Beak, claws become to harden
Embryo continues to grow and moves into position to break
the shell
Day 20-21
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yolk sac completely drawn into body cavity;
embryo occupies practically all the space within the egg
except the air cell
When the air cell is broken, the embryo only has a limited
time to pip its way out of the egg.
WHAT IS THE PROCESS OF CHICK DEVELOPMENT DURING
INCUBATION?
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http://www.youtube.com/watch?v=tof5b1Qs_OE&feature=related
WHAT ARE THE VARIOUS STAGES IN THE EMBRYONIC
DEVELOPMENT OF A CHICKEN?
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A. The blastoderm spreads over the yolk.
 1. The blastoderm differentiates into two layers, known as the
ectoderm and entoderm, by a process known as gastrulation.
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2. The ectoderm, forming first, creates the skin, feathers, beak,
claws, nervous system, eye lens and retina, and linings of both
mouth and vent.
3. The entoderm, forming second, creates the linings of the
digestive tract, as well as the respiratory and secretory organs.
4. A third layer, the mesoderm, finally gives rise to bones,
muscles, blood, and reproductive and excretory organs.
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B. Membranes cover the developing embryo for
protection and aid in development.
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1. The chorion is a membrane that surrounds the yolk sac
and amnion during chick development.
2. A transparent sac, known as the amnion, is full of colorless
liquid that surrounds the embryo. The amnion serves as a
cushion and provides protection for the developing embryo.
3. The allantois is a sac connected to the abdomen of the
developing chick that makes respiration possible it stores
excretions, absorbs albumen for food, and gets calcium from
the shell for the structural needs of the embryo.
WHAT FACTORS WILL AFFECT THE HATCHABILITY OF
EGGS?
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Hatchability refers to the percentage of fertilized eggs
that hatch.
A. Factors that affect hatchability include:
 1.
Fertility, the capacity to reproduce, is affected
by:
 a.
number of females mated to a single male.
 b. age of breeding animals.
 c. length of time between breedings.
 d. management practices.
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Genetics, or genetic makeup of the bird, is
affected by:
 a.
inbreeding
 b. crossbreeding
 c. lethal genes
 d. heritable traits (ex. egg production)
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Nutrients, available to the developing chick,
are affected by:
 a.
rations fed to breeding hens.
 b. amount of vitamins and minerals in hen rations.
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Diseases of breeding stock.
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Egg Selection. Certain physical characteristics
can affect hatchability.
 a.
Size. Extremely large or small eggs do not hatch
well.
 b. Shape. Unnaturally shaped eggs do not hatch well.
 c. Shell quality. Strong shells hatch better than weak
shells.
 d. Interior quality. Upon candling, better interior
quality eggs tend to hatch better.
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Handling of fertilized eggs. Good
management practices include:
 a.
Gathering eggs frequently.
 b. Clean soiled eggs.
 c. Sanitizing eggs.
 d. Hold, or prolong start of incubation, for a minimum
amount of time.
 e. Hold eggs at a temperature of 65 degrees F.
 f. Keep eggs at a relative humidity of 75 to 80%.
 g. Position eggs with large end up.
 h. Turn eggs if they are held for more than 7 days.
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C. In commercial hatcheries, two separate incubators
are used for hatching.
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1. Incubation of the chick from day 1 through day 19 is done
in an incubator known as the setter. The setter has the
environmental conditions discussed earlier.
2. Days 19 through 21 are usually spent in an incubator
known as the hatcher. The hatchers have slightly lower
temperatures (98 degrees) and have chick holding trays that
cut down on the debris from hatching eggs that may cause
disturbances to other eggs.
3. Incubation times depend on the species of bird being
hatched.
HOW DO WE PREPARE EGGS FOR HATCHING AND CARE
FOR YOUNG BIRDS DURING BROODING?
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D. Brooding refers to the care of young poultry from the time of hatching through
eight to ten weeks of age.
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Chicks should be removed from the incubator when they have dried and the
down becomes fluffed. This drying normally takes about 12 hours.
1. Certain environmental conditions are needed for proper brooding.
 a. Temperature—When chicks are one day old, the temperature should
be between 90 and 95 degrees F. The temperature is generally lowered
five degrees per week until a temperature of 70 to 75 degrees is
reached, or until the chicks are fully feathered.
 b. Ventilation—Proper ventilation provides fresh oxygen, removes carbon
dioxide, carbon monoxide, ammonia, and keeps bedding dry.
 c. Moisture—50 to 60% relative humidity is recommended for good
feathering.
 d. Space requirements—Each chick needs 7 to 10 inches of space under
the brooder. More brooder space may be required during colder weather
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