FEMALE REPRODUCTIVE SYSTEM

Birds are unique among animals as they reproduce through an egg .

Two parts

1)Ovary

2)Oviduct

At the time of early embryonic development, two ovaries and two oviducts are present.

left pair develops and functional in all species of birds

Kiwis - both the left and right ovaries develop and only the left oviduct develops

Female Reproductive System:

Ovary

• Mature ovary consists of

numerous developing

follicles

– Appears like a

cluster of grapes

Ovary The left ovary is situated at dorsal part of abdominal

cavity and the fore end of kidneys

is attached to the abdominal cavity wall by the meso-ovarian ligament

ovary is a cluster of developing yolks or ova

At hatch, pullet chicks have tens of thousands of potential eggs. Most of these, however, never develop to the point of ovulation.

Each ovum surrounded by a vitelline membrane. As the ovum develops, yolk is added.

The color of the yolk comes from fat soluble pigments

called xanthophylls contained in the hen’s diet.

Hens fed diets with yellow maize, or allowed to range on grass, typically have dark yellow yolks.

Hens fed diets with white maize, sorghum, millet or wheat typically have pale yolks.

The color of the yolks improved by marigold petals (xanthophylls ).

Ovary/yolk The liberation of ovum from graffian follicle is called

Ovulation

Ovulation occurs normally 14 to 75 minutes after oviposition (the laying of the fully formed egg).

yolk size in the egg - up to 40 millimetres in diameter .

on the distal surface of mature follicle have a elongated area which is free of blood vessels called as stigma, is where the follicle normally splits to release the yolk into the oviduct.

If the follicle splits at other than the stigma, the numerous blood vessels will rupture and result in blood spot in egg.

Occasionally the vitelline membrane is damaged and pale spots develop on the yolk called as mottling

A high incidence of yolk mottling

use of Nicarbazin & Piperazine and dibutylindialaurate

cottonseed meal (gossypol) and sorghum (tannin)

A calcium deficient diet.

Photograph of the ovary of female

chicken, indicating the location of the

stigma on an ovum

stigma

Blood spot in yolk

Meat spots in egg white.

They are formed when small pieces of the wall of the

oviduct are sloughed off when the egg is passing through oviduct (candling)

Female reproductive system

oviduct

The oviduct is a long zig zag tube (25-27 inches long) consisting of glandular and muscular parts .

Oviduct extends from the ovary to the cloaca.

It has 5 distinct parts, viz.

1) infundibulum (9cm),

2) magnum (33cm),

3)isthmus (10cm),

4)uterus (10-12cm)/shell gland

5)vagina (12cm)

S.No Part Length Time spent Function

1 Infundibulum 9 cm 18 mins 1)Engulfs yolk

2)Reservoir for

spermatozoa, 3)Fertilization

2 Magnum 33 cm

(largest

portion)

2 hr 54 mins Thick white or albumen (40

%) added

3 Isthmus 10 cm 1 hr 15 mins Some albumen and inner

and outer shell membranes

are added

4 Uterus/shell

gland

10-12 cm 20 hrs 40 mins Shell (CaCo3) over the egg

(47%calcium from her

bones), pigment deposition

(Porphrin- brown color)

5 Vagina

(Muscular

portion)

12 cm Cuticle is added,

helps in expelling the egg

during oviposition

Total 74 cm 25-26 hours

Fertilization

• Shell formation takes

24-26 hours to

complete

• Hen’s body

temperature 104 -

106o F

PROCESS OF EGG FORMATION The yolk is not the true reproductive cell

When the female attains sexual maturity (FSH)-mature ovum inside the graffian follicle grows rapidly.

The yolk weight also increases 7 days prior to ovulation due to the deposition of yolk material over the ovum in (alternate layers of white and yellow)

white layer -night time

yellow layer - day time

due to the deposition of yolk, the nucleus migrates from the centre of the ovum to the periphery and lies underneath the vitelline membrane

The nucleus of the infertile egg is called 'germ spot' and that of fertile egg 'germ disc'

The anterior pituitary - FSH - that regulates the growth and maturity of graffian follicle

Luteinising hormone (LH) that helps to release the ovum by rupture of graffian follicle

Ovulation

oviposition (laying of egg)

Albumin - Magnum

Inner and outer shell membranes & water – Isthmus

Egg shell (CaCo3)and cuticle – uterus/shell gland

The tubular and unicellular glands present in uterus which secrete a watery fluid and added to the albumen through the shell membranes

5 hours before the oviposition shell pigments are added.(brown colour –Porphyrin)

laying of egg, is through the contraction of uterus.

oxytocin and vasotocin responsible for uterine contraction and Oviposition.

Four Major structures from outside to inside are

Shell Shell membranes AlbumenYolk

Anatomy of an Egg

1. Eggshell2. Outer membrane3. Inner membrane4. Chalaza5. Exterior albumen6. Middle albumen7. Vitelline membrane8. Nucleus of pander9. Germinal disk10. Yellow yolk11. White yolk12. Internal albumen13. Chalaza14. Air cell15. Cuticula

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Egg structure

EGG SHELL Cuticle

Spongy or calcarious layer

Mammillary layer or matrix and pores

Microscopic Pores- 8,000-10000 per egg, distributed unevenly over the shell surface (more at broad end than narrow end).

Exchange of volatile compounds between the shell membrane and cuticle.

CaCo3

SHELL (10 %) calcium carbonate (CaCO3) 94-97 %,

3-6 % Organic material and Pigment Shell strength is depend on the

content of CaCO3, Mg, P, dan vit D Thickness: 0.2-0.4 mm Pores: 700 pores/cm2 = 17,000 tiny

pores Semipermeable membrane: air and

moisture can pass through that helps keep out bacteria and dust.

Mucin : covered shell and pores

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SHELL MEMBRANE Air cell

Outer shell membrane

Inner shell membrane

Air cell is situated in between the two membranes at the broad end

Air cell - formed as a result of contraction of the egg contents, soon after oviposition, due to differences in the temperatures exposed to by the egg prior to and after oviposition

The outer shell membrane is attached to the shell.

The inner shell membrane closely surrounds the albumen

ALBUMEN consists of 4 layers

Chalaziferous or inner thick white, which forms (3%)

Inner thin albumen (17%)

Outer thick firm or dense albumen (57%)

Outer thin albumen (23%) of total albumen

The chalaziferous layer -very close to the yolk immediately surrounding the vitelline membrane of the yolk –

This layer twists into two chords on either sides of the yolk called chalazae, which are formed due to rotational movement of the egg in the oviduct

ALBUMEN (60 %) contain approximately 40

different proteins:

OVALBUMIN, CANALBUMIN, OVOTRANSFERIN, LYSOZYM, OVOMUCIN, AVIDIN, ETC

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Consist of 4 parts: innerthick, inner thin white,outer thick white dan outerthin white.

cloudy appearance due toCO2 content.

ALBUMEN

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Functions of chalazae

Chalazae - hold the yolk central position and thus serves as an anchor for yolk

Chalazae - contain a protein called lysozyme, which is possessing antimicrobial properties and helps to prevent the microbial spoilage of the egg

Ageing, improper storage and microbial spoilage makes thick albumen watery

YOLK Latebra is the centre of the yolk, which is a small,

nearly circular core of light coloured fluid, which does not completely harden on boiling

Nucleus of Pander is a cup-shaped structure, which is an extension of the neck of latebra, connecting the base of the germinal disc

Germinal disc located on the surface of yolk, from here Embryo formation begins.

"Vitelline membrane" is a semi-permeable elastic membrane, surrounding the yolk, separating the yolk material from the albumen

Fertile and Infertile Eggs

Infertile egg Fertile egg

In an infertile egg it is unicellular (ovum) and contains haploid number of chromosomes, called "Blastodisc". It is circular in shape, with a diameter of about 3.5 mm and with vacuoles in it.

Where as in a fertile egg, it is a multicellular structure having diploid number of chromosomes, called "Blastoderm". It is oval in shape, with an average diameter of about 4.5 mm and with no vacuoles in it.

Clutches Birds lay eggs in clutches

Eggs laid on successive days are called a clutch.

Clutch size is an individual characteristic and may vary from 2 up to 100 eggs.

However, the normal clutch size is from 3-8 eggs.

The larger the clutch size – good layers

Small clutch size indicates an inferior layer.

ovulation usually occurs in the morning and almost never after 3:00 PM.

Ovulation of a yolk for the next egg in a clutch occurs within an hour of laying the previous egg.

and so that each day the hen gets later and later in her timing.

Since hens do not typically ovulate after 3:00 PM, the next ovulation is delayed until at least the next day and egg laying is interrupted.

This delay results in the break between clutches and the

cycle repeats itself a day or so later. PHUSE

double-yolked eggs This phenomenon can be related to hen age but

genetic factors are also involved.

Young hens sometimes release two follicles from the ovary in quick succession.

Physical and Chemical composition of Eggs

1. As egg cools, contents contract and air cell formed.

2. Cuticle or bloom begin to dry.

3. Size of the pores increase.

4. Albumen gives off carbon dioxide, and carbonic acid breaks down.

5. The white changes from almost neutral (pH 7.6) to alkaline (pH 9.7).

6. The mucin fibers becomes watery.

Physical-Chemical Breakdown ofEgg Quality - I

Yolk absorbs water from albumen, swells and become a round flabby mass.

The egg becomes an inedible product when the yolk settles to shell and becomes attached (stuck yolk).

Vitelline membrane brakes (mixed rot)

Nutrient Composition of An Egg

* Protein – 6-7 g, highest quality.

* Fat – 5-6 g, readily digestible.

* Carbohydrate – low in calories.

* Vitamins – generous quantities

except Vitamin C.

* Yolk is high in cholesterol

%

PERCE

NTAGE

WATER PROTEIN FAT ASH

WHOLE

EGG

100 65.6 11.8 11 11.7

WHITE 58 88 11.0 0.2 0.8

YOLK 31 48 17.5 32.5 2.0

Chemical Composition of Egg

Protein Quality

Egg – 100

Milk – 80

Beef – 79

Fish – 66-88

Chemical composition of eggs

AnimalWater

(%)

Protein

(%)

Lipid

(%)

CHO

(%)

Ash

(%)

Chicken 73,7 12,9 11,5 0,9 1

Duck 70,4 13,3 14,5 0,7 1,1

Goose 70,4 13,9 13,3 1,5

Pigeon 72,8 13,8 12 0,8 0,9

Quail 73,7 13,1 11,1 1 1,1

Ostrich 72,6 13,1 11,8 1,7 0,8

Turtle 66,7 16,5 11,6 3,3 1,9

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Albumen

Proteins Lipids Carbohydrates Ash Water

9.7-10.6%, 0.03% 0.4-0.9% 0.5-

0.6%

87.9-

89.4%

Composition of Albumen (Powrie 1973)

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Ovalbumin 54%

Conalbumin 13%

Ovomucoid 11%

Lysozyme 3.5%

Globulins (G2, G3) 8.0 %

Ovomucin 1.5%

Other protein components include, flavoprotein(0.8%), ovoglycoprotein (0.5%), ovomacroglobulin(0.5%), ovoinhibitor (0.l%) and avidin (0.05%).

MAJOR PROTEINS IN ALBUMEN OF TOTAL PROTEINS (Powrie 1973)

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Egg white contains approximately 40 different

proteins:

Vitamin

contain most of the recognised vitamins with the exception of vitamin C

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VITAMINS

Component Amount per 100 g egg

Vitamin A 190 µg

Vitamin D 1,8 µg

Vitamin E 1,1 mg

Vitamin C none

Thiamin (B1) 0,09 mg

Riboflavin (B2) 0,47 mg

Niacin 0.1 mg

Vitamin B6 0.12 mg

Folate 50 µg

Vitamin B12 2,5 µg

Biotin 20 µg

Panthotenic acid 1.77 µg45

Minerals

• Iodine thyroid hormone

• Phosphorus for bone health.

• Zinc for wound healing, growth and fighting infection

• Selenium an important antioxidant

• Calcium for bone and growth structure and nervous function.

• also contain significant amounts of iron, the vital ingredient of red blood cells.

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Lipids in Yolk Egg lipids are found mostly in yolk, only 0,05% is

contained in albumen.

Fatty acid content:

monounsaturated (46.5%) > saturated (37.5%) > polyunsaturated (16.5%)

Highest fatty acid content:

monounsaturated: oleic acid (18:1) approximately 40% from lipid total.

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1. One medium egg contains between 4-5 grams of fat

2. High cholesterol

• ~200 mg/egg

3. High in Complete Protein (EPR=93.7%); > milk (84.5%), fish (76%), beef meat (74.3%), soy bean (72.8%), corn (60%)

4. Little to no CHO

5. High in vitamins & minerals

• Vitamins ADEK, some B vitamins, selenium, iodine, zinc, iron, copper

Energy value of eggs

• 78 kilocalories (324 kilojoules)

Protein• Egg protein is of high biological value as it

contains all the essential amino acids needed by the human body.

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Functional Properties of Egg

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1. Flavor, color, nutrition

2. Foaming agent

3. Emulsifying agent

4. Aids in thickening/structure

5. Binding/coating agent

6. Leavening agent

FOAMING PROPERTIES

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1. Air trapped in a liquid

2. In egg foam, air trapped by protein.

3. Denatured and then coagulates

4. Heat expands protein/air

• Important to souffles, meringues, omelet, andsponge cake.

EMULSIFIER CAPACITY

Egg yolk is a source of lecithin, an emulsifier andsurfactant.

Lechitin is a substance that helps an emulsionform, or helps keep an emulsion from separating

Aplication :• Mayonnaise• butter sauces• salad dressing• Stabilizer of bakery products• Whipped egg

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Properties Application

Thickening Eggs thicken foods like custards puddings, sauces,

and creamy fillings

Leavening Souffles, sponge & butter cakes, quick breads, and

puffy omelets are leavened by eggs

Coating Meat dishes, breads, and cookies are some foods

with egg components as the base ingredients for

coatings

Binding Eggs bind other ingredients for making meat loaves,

casseroles, and croquettes

Emulsifying Eggs prevent mixture separation in mayonnaise,

salad dressing, and cream puff filling

Clarifying Tiny particles are coagulated in soups and coffee to

create a clear solution

Retarding

Crystallization

Crystallization of sugar is slowed in cake icings and

candies53

ANTIMICROBIAL AND ALERGEN ON ALBUMIN

LYSOZYME

Immunoglobulin E (IgE)

OVOMUCIN (hambat enzim tripsin)

AVIDIN:

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Benefit of Egg Components Sialic acid could prevent infection

Immunoglobulin in yolk can play a role as antibody.

PHOSVITIN has a function as food antioxidant.

Choline: aids brain function and enhances thinking capacity and memory. It is an important part of a neurotransmitter that helps preserve the integrity of the electrical transmission across the gaps between nerves.

Lutein and zeaxanthin: contribute to improving eye health and protecting eyes from ultraviolet rays

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Allergen in Egg There are 4 proteins in egg white may provoque

an allergy:

- ovomucoid (11%)

- ovalbumin (54%)

- ovotransferrin (12%)

- lysozyme (3.5%)

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Egg Allergy SymptomsEgg allergy is like most food allergy reactions: It usually

happens within minutes to hours after eating eggs.

the skin - in the form of red, bumpy rashes (hives), eczema, or redness and swelling around the mouth

the gastrointestinal tract - in the form of belly cramps, diarrhea, nausea, or vomiting

the respiratory tract - symptoms can range from a runny nose, itchy, watery eyes, and sneezing to the triggering of asthma with coughing and wheezing

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Misconceptions About Nutritive Value of Eggs

1. Pay more with the desired shell color for nutrient.

2. Deep yellow yolk are higher in nutritive value.

3. Fertile eggs are more nutritive than non-fertile eggs.

4. Organic eggs are safer and more nutritious.

5. Raw eggs are more digestible than cooked.

THANK YOU

Eggcellent!!!!