1. Revision of Poultry Biology
Birds & Poultry
PoultryBirds
Domesticated birds including chickens,
turkeys, ducks, geese, quail, pigeon & ostrich.
Both domesticated & undomesticated species of class
Aves. About 10000 avian species in 27 orders.
N.B Some author classifies RABBITS with poultry although they are mammals.
Aims of poultry production:
1-Meat production → commercial broilers" Hubbard, Ross, Coob 500 & 700, Avian 48 and
Arboplus" & cross-bred broilers "Saso breed". In addition Turkeys, ducks, ostriches and quails are
reared for meat production.
سللتيالكبوالروصمنالسللتعاليةالحتياجاتمنناحيةالطاقةالممثلةوالبروتينوالمثيونينوالليسينفي
حينأنسللتالفيان48والربورأيكرزوالربوبلصمنالسللتمتوسطةالحتياجاتأماسللةالهبردفهيمن
السللتكلسيكيةالحتياجاتفيحينأنسللةالساسومنالسللتمنخفضة.الحتياجات
2-Table egg production → commercial layers as Hi Lyne, Hisex, Bovans and Lohmann.
تتميزسللةاللوهمانبأنتاجيتهاالجيدةولكنيعيبهاأنهاتستهلكعلفاأكثركماأنهاسللةعصبيةالنزعةوذلكعكس
كلالسللت.الخري
3-Fertile egg production → Breeders "Breeder of Hubbard, Ross, Coob 500 & 700, Avian 48 and
Arboplus" & Saso breed".
4-Feather production → ostrich.
5-Fun → Pheasants, Sparrows, Parrot and pigeon.
The differences between commercial layers & breeders.
BreedersCommercial layersCriteria
Fertile eggTable eggAim
EssentialsNot presentMale
Deep litter onlyDeep litter or cagesSystem of housing
Not less than 3 kgNot more than 2 kgWeight of hen
Not less than 80 gmNot more than 60 gmWeight of egg
Not less than 150 gmNot more than 120 gmAmount of
feed/hen/day
LowerHigherFeed intensity
Not more than 180 eggNot less than 300 eggEgg productivity/year
About 70 weeks.About 60 weeks.Life Span
Classic with IBD, Reo, CIA.Classic without IBD, Reo, CIA.Vaccination schedule
2. Mention the poultry terms:
Broilers: reared till 6-7 wk old either six (2 kg),
Tender and easy to cook, 800 million in Egypt.
Roaster: Older & slightly larger than a
broiler.
Capon: Castrated ♂ chicken at 5-7 month old
weighs about 4 kgs.
Chick: Young chickens.
Poult: young turkeys. Pullet: semi-mature chickens.
Duckling: young ducks. Gosling: Young geese.
Squab: Young pigeon. Tom (Gobbler): matures ♂ turkey.
Hen: mature ♀ chicken, turkey, duck & geese. Drake: mature male duck.
Gander: adult male goose. Gaggle: group of geese.
Avian unique Characteristics
I-Anatomical characteristics:
1-Feathers + no sweat glands + sparse distribution of sebaceous glands + uropygial or preen or oil
bag or gland that is well developed in aquatic birds, in addition to the scales onto legs and feets.
2-Modified forelimbs into wings for flying in most birds and modified hind limbs for walking,
swimming or perching.
3-Birds have no teeth and the lips are replaced by horny beaks of different shapes according to
species. It is modified for prehension of feeds.
4-Presence of fused skeleton in certain area of vertebral column e.g. synsacrum "fusion of the
14th
and 15th
vertebrae of the caudal region of the vertebral column".
5-The presence of air sacs which will be discussed later. They have very important functions in
avian respiration.
6-Avian species have no diaphragm and the thoracic, abdominal & pelvic cavities are fused in
one celomic cavity. The fusion of body cavities in birds facilitates the transmission of infections
in-between the visceral organs.
7-Avian species have no urinary bladder and urethra and the two ureters originate from the
two kidneys and open directly in the cloaca.
8-Avian species are characterized by the presence of the cloaca "universal sac having 4
openings; the coprodium (opening of intestine), the urodium (opening of ureters), the
proctodeum (opening of vas deference in male and the left oviduct in female) and the opening
of bursa of Fabricius.
9-Avian females have 2 ovaries and 2 oviducts but the right ones are atrophied and un-
functional while the left ones are the only active ovary and oviduct.
10-Avian species have no lymph nodes except for ducks and geese in which there are two
primitive lymph nodes, each of which is located along the side of the femur.
3. II-Physiological characteristics:
1-Avian digestive system is of low physical limitation, so, the avian feeds should be
nutritionally concentrated, having all nutrients and easily digested and absorbed.
2-The activity, number of heart beats, respiratory rhythm, metabolic and growth rates of avian
species are higher than those of the mammals, so the nutritive requirements of the former are
higher than in the latter.
3-Avian R.B.Cs are nucleated, avian neutrophilis are modified to hetrophils and avian blood
platelets are true cells "thrombocytes". Avian antibodies are only three types "IgG, IgM and
IgA".
نظرالنكرياتالدمالحمراءAvian R.B.CsوالخلياالتجلطيةThrombocytesتحتويعلينواةفمنالمحتملأن
تحتويعليMHC-Iوبالتالييكونلهادورهامفي.المناعة
4-The avian species are warm-blooded animals i.e. constant body temperature is whatever the
ambient temperature.
5-The avian species are oviparous i.e. reproduction via internal fertilization and external
brooding of eggs.
6-Avian species are uricotelic i.e. their end product of protein metabolism is uric acid.
N.B. Animal species are classified according to their end product of protein metabolism into:
Ureatelic "all mammals except for ruminant and Dalmatian dog"; Allantolotelic "ruminant and
Dalmatian dog"; Amoniatelic "Fish" and Uricotelic "Poultry“. Avian species are uricotelic i.e.
their end product of protein metabolism is uric acid.
External Avian Anatomy
Skin: it is thinner and more delicate than that of mammals. The color of the skin varies
according to species, breed, age and diet.
Feathers: cover almost the entire surface of bird. Grow from feather follicles, which are
organized into feather tracts. Feather tracts are named according to the structure they are
associated with e.g. the femoral feather tract is on the thigh, which contains the femur. It
insulates and protects skin from getting wet or injured. It also helps birds to fly or glide. Newly
hatched chicks have down .الزغب Feathers begin growing in a few days and are grown by 4-6
weeks. Second feather growth at 2-3 months. Final feather growth occurs at sexual maturity.
Feather patterns and colors vary with breeds and varieties. Male feathers have pointed tips;
female feathers have rounded ends.
Molting: Hens molt (lose feathers) once a year when they stop laying eggs. Most birds molt and
replace their feathers by growing new ones.
Comb & wattles are external structures on the head of birds and are largely ornamental .للزينة
The size and color of them are correlated with the gonad development and secretion of the sex
hormones. The red color of the comb and wattles is attributed to the high vascularity of the
4. dermis covering them. They have different characteristic features in male vs. female birds, and
among different poultry species. Snoods and whiskers (beards) are the external structures in
turkeys' equivalent to the comb and wattles.
Uropygial, preen, oil gland or oil bag: it is the only significant gland of the skin that is located
dorsally near the tip of tail. It is present in all birds but well-developed in water fowls. In the
chicken, two lobes drain through a median nipple-like papilla. Its function is somewhat uncertain
but preening birds take oil from it and apply it to their feathers. It also has a function in vitamin D
and calcium metabolism.
Avian Skelton: the avian skeleton has the following characteristics:
-Essentially modified for flight: Supports flight muscles (pectoral girdle, keel/sternum) to
withstand the stress of flight.
-The forelimbs are modified into two wings.
-There are fewer and fused digits.
-It has a reduced mass.
- It has Fused bones adding rigidity e.g. synsacrum which resulted from the fusion of the 14th
and
15th
vertebrae of the caudal region of the vertebral column.
5. - It has pneumatic bones العظامالهوائية : major bones hollow "Not completely hollow" with
struts, air spaces connected to respiratory system. Major bones of body are pneumatic.
Lack teeth- lightweight beak.
Beak: it is composed of hard-keratinized epidermal tissue. This rostral structure forms part
of the upper and lower jaws. The beak functions much like the lips and teeth of mammals.
Debeaking is the removal of approximately one-third of the upper and lower level. In
some cases, only the upper beak is removed. Debeaking is used in poultry industry to
prevent cannibalism.
Medullary bone العظامالنخاعية forms in hens during egg production, providing calcium.
The sternum, “keel or breast bone” is a single large bone on the ventral surface of the body.
Ribs are divided into two types. The vertebral ribs are those that originate from the vertebral
column. The sternal ribs are those that originate from the sternum (keel, breast bone).
6. Birds have no teeth: However, they can digest food 6 times faster than mammals. How does it
happen? There are two essential adaptations, the crop and the two stomach system. The Crop is
a storage unit for easy gluttony and escape. The two stomachs are the upper (Proventriculus)
and the lower (Gizzard). The upper adds the enzymes and the lower crunches the feed.
Wings, Feet and Legs: Chickens’ legs have scales; most chickens have 3-4 toes with claws used
in scratching. Domestic chickens have wings but cannot fly well or at all. Lighter birds can fly
short distances and clear fairly high fences.
7. Chicken Muscles
Dark meat: Red fibers with more myoglobin (oxygen carrying protein) for greater aerobic
metabolism e.g. Leg muscles.
White meat: White fibers containing very little myoglobin e.g. breast meat.
The avian digestive system:
Mouth & pharynx: tongue, beak, choanal cleft, no soft palate, salivary glands and taste buds.
Mouth secretions: Mucus (lubricant), amylase in some species and adhesive saliva.
Esophagus: long, contains mucus glands.
Crop (ingluvies)...Variable in size and shape
مطلوبهناتحديدأثرالشكلعليحدوثبعضالمراضمنناحيةومنناحيةأخريأثرهعلينظمالتغذية
Produce crop “milk” in pigeon and doves under the influence of prolactin hormone.
Esophagus and crop secretions: Mucus and if amylase is secreted in saliva there may be CHO
digestion in crop.
Proventriculus: fusiform, variable relative size. It has chief cells and mucus cells. The
secretions are HCl and pepsin "Chief cells" and mucus "Mucus cells".
Gizzard (ventriculus)
-Two pairs of muscles "thin and thick". It has koilin "protein lining whose color is related to
bile pigments". It is responsible for the mechanical digestion. It has special digestive functions
(grit - small bits of stone retained in the gizzard).
8. -Small intestine: duodenal loop, jejunum and ileum. Shorter than mammals. Chemical or
enzymatic digestion and absorption. The intestinal Secretions are amylase, saccharidases,
peptidases, lipase, maltase, isomaltase Enterokinase and Sucrase.
-Liver: relatively large, left and right ducts and gall bladder may or may not be present. The liver
secretions - bile "Emulsifies fats, contain lipase and activates pancreatic lipase".
-Pancreas: lies in duodenal loop, has three ducts. The secretions are bicarbonate, chymotrypsin,
trypsin and amylase.
-Ceca: single, paired or absent, short, junction of ileum and colon, ilieocecal valves, fermentation
and fiber digestion.
Colon or rectum: short, ilieocecal junction to cloaca and water balance
Cloaca: universal sac having 4 openings; the coprodium (opening of intestine), the urodium
(opening of ureters), the proctodeum (opening of vas deference in male and the left oviduct
in female) and the opening of bursa of Fabricius. It is responsible for excretion, mineral and
water balance.
الفروقبينالجهازالهضميفيالطيور:والثدييات
.القانصة فى الموجودة الحصى بمساعدة القانصة في الغذاء طحن معظم يتم لذا بالفم أسنان وجود -عدم
محدودة سعة ذات طول قصيرة حجما صغيرة للدواجن الهضمية -القناةLow physical limitation of digestive system.
) الهضمية بالقناة هضمه أثناء الغذاء مرور معدل -زيادة3–8الهاضمة الفرازات وتأثير لفعل الغذاء تعرض وقت فان وبالتالي (ساعات
.الغذائية القيمة عالي الحجم صغير الهضم سهل مركز علف إلى بأنواعها الدواجن تحتاج لذا قليل
الطاقة من خصوصا المختلفة الغذائية العناصر من فاحتياجاتها لذا الثديية الحيوانات من وحركة وحيوية نشاطا أكثر الطيور أن ويلحظ
الخارجية البيئة بمؤثرات وحساسية تأثرا أكثر الطيور أن كما منها نسبيا أعلى المعدنية والعناصر والفيتامينات والبروتينات الممثلة العلفية
.عامة بصفة والقتصادية النتاجية الحياة وقصر الحياة دورة بسرعة وتتميز
أنواع:الهضم
1-الهضمالميكانيكيMechanical digestionويشملالمضغMasticationفيالفمبواسطةالسنانفيالثدييات
وليحدثفيالطيورلعدموجودأسنانبهاولكنيحدثجزئيانتيجةللفعلالجزئيللحوصلةوكذلكللطحنفي
القانصةفي...أذن الدواجنهوضعيفالتأثيرفي.الطيور
9. 2-الهضمالميكروبيdigestion Microbialويشملالهضمفيالكرشفيالمجتراتوالعورينفيالفصيلة
الخيليةوالرانبوالطيوروتقومبهالكائناتالدقيقةالنافعةالموجودةفي...أذن الكائنهوضعيفالتأثيرفي.الطيور
3-الهضمالكيماويأوالنزيميChemical or enzymatic digestionويشملعملياتالهضمفىالمعدةالعاملة
أوالحقيقيةفيجميعالكائناتويتماعتماداعلىإفرازالنزيماتالنوعية.الهاضمة
النوعينالولينمنالهضممحدودانفيالدواجنحيثأنأنواعالدواجنالمختلفةليسبهاأسنانلذافالهضم
الميكانيكيمحدودوليتواجدإلفيحركية...أما القانصةعنالهضمالميكروبيفهوأيضامحدودوليتواجدإلفي
..وبسبب العورينمحدوديةالهضمالميكانيكيوالميكروبينجدأنالموادالخشنةكالليافليمكنأويقلبشدة
...أما هضمهاالساسفيعملياتالهضمفيالطيورهوالهضمالكيماويأوالنزيميبالتاليلبدمنغذاءمركز
قليل.اللياف
Summary of Physiology of Digestion
G.I Tract
Region
Enzyme
(secretion)
Substrate End Product pH
Mouth Saliva Lubricates and softens food --
Crop Mucus Lubricates and softens food 4.5
Proventriculus
& gizzard
HCI
Pepsin
Lowers stomach pH 2.5
Protein Polypeptides
Duodenum
Trypsin,
Chymotrypsin &
Elastases
Carboxy-
petidases
Collagenase
Proteins,
Peptones &
Peptides
Peptides
Collagen
Peptones,
Peptides and
amino acids
Peptides &
amino acids
Peptides
6.0 to 6.8
Jejunum
Peptidases
Polynucleotidase
Peptides
Nucleic acids
Dipeptides &
amino acids
Mononucleotides
5.8 to 6.6
Avian Respiratory System:
Very efficient, unidirectional biphasic air flow. Presence of air sacs "Average of 9 in number",
Serve variety of functions and lack muscular diaphragm. Small lungs (2% of body volume)
connected to large air sacs (~10X larger).
Respiration: Smallest birds have fastest breathing rates. Air sacs make the body lighter for
flight and are part of the respiratory system. Birds are susceptible to respiratory diseases that
spread beyond the lungs into the abdominal cavity and bones.
10. Pneumatic bone: discussed before. العظامالهوائيةتمشرحهافيالجهازالهيكلي .
The differences between respiratory system of poultry and mammals.
Criteria Respiratory system "poultry" Respiratory system "mammals"
lung Non tidal Tidal
Air sacs Present Not present
Respiration Unidirectional bi-phasic Unidirectional uni-phasic
Air Sacs in Poultry: The air sacs are named according to their location:
1. Cervical air sac: in the neck.
2. Interclavicular air sac: between the clavicle.
3. Anterior thoracic air sac: fore portion of the chest below and in contact with the lungs.
4. Posterior thoracic air sac: hind portion of the chest (thorax), behind the lungs in the area
between the lungs and the reproductive organs.
5. Abdominal air sac: behind the last rib backward to the pelvic cavity. Air sacs form in the
embryo in pairs but some fuse forming a single sac. Not all classes of poultry have the same
number of air sacs because different species fuse different pairs of air sacs.
The following are the air sac specifications for different species of poultry: Air sac diverticula
are out-branchings of the air sacs. The cervical air sacs have diverticula into vertebrae of the
neck, back and ribs. The interclavicular air sacs have diverticula into the breastbones and the
bones of the shoulder girdle as well as around the shoulder joint. The thoracic air sacs have no
11. diverticula. The abdominal air sacs invest the abdominal viscera and extend into the kidney
crypts. They have diverticula around the hip joints.
Duck air sacs Turkey air sacs Chicken air sacs
Cervical 1 pair Cervical Fused Cervical 1 Pair
Interclavicular Fused Interclavicular 1 pair Interclavicular Fused
Anterior thoracic 1 pair Thoracic 1 pair Anterior Thoracic 1 pair
Posterior thoracic 1 pair Abdominal 1 pair Posterior Thoracic 1 pair
Abdominal 1 pair Abdominal 1 pair Abdominal 1 pair
The avian cardiovascular System:
Circulation: A chicken heart is four chambered. Chicken heart beat are about 200-300 times/minute.
Smallest birds have highest heart rates and relatively larger hearts than larger birds. 1.5-2 X larger
than in comparable mammals. Maintain higher metabolism. Heart size increases with altitude for
same species. There are separate systemic, pulmonary circulations. Homeotherms.
Blood Pressure: Slightly higher than mammals' → Aortic ruptures may occur in turkeys.
Aorta: it is the main vascular trunk in birds and aortic arch is the curvature of aorta after
leaving the heart which is weak in nature leading to aortic rupture in heavy weight turkeys.
12. The avian Urinary system:
The urinary system of the chicken does not contain a urinary bladder. There are two
trilobed kidneys, one on each side of the ventral surface of the vertebral column. This pair
of kidneys is embedded in the deep bony crypts of the pelvic and synsacral area of the
skeleton. Ureters carry the urinary waste to the cloaca. The uric acid is discharged into the
cloaca and excreted with the feces. The white pasty material in chicken droppings is
considered to be urinary system excretion. Birds excrete their nitrogen waste as uric acid,
whereas mammals excrete it in the form of urea.
Excretion: Kidneys & salt glands, Kidneys similar to mammal kidneys but 2X as large (relative),
more rapid metabolism and not as efficient at removing salt → need for salt glands.
Kidneys produce uric acid rather than urea. Requires less water (not as toxic as urea).
Uric acid works well in dry climates, conserves weight, Water not needed in large quantities,
Wastes dumped into cloaca (no urinary bladder), mixed with feces, forms white paste with dark
lumps.
Salt glands in head concentrate salt 3-5X that in blood discharge through nostrils especially
active in marine birds. There is no urinary bladder; urethra and the ureters are open directly in
the cloaca.
Define with examples: Ureatelic, allantolotelic, uricotelic & amoniatelic: Discussed before
The avian Reproduction
Different from mammals in: oviparous and not viviparous.
Male reproductive anatomy: Paired testes grow during breeding season; shrink otherwise,
up to 200-300X difference in size between seasons. Left testis is slightly larger than right. Vas
deferens is wavy tubes.
13. Mature sperm collect until transferred. End nearest cloaca may swell to serve as storage sac.
Copulatory organ "phallus" present in more primitive birds e.g. flightless ratites, galliformes,
ducks & geese, erectile, grooved structure used to guide sperm into female’s cloaca during
copulation.
Birds lacking feature just press cloacal openings together.
Sperm development "spermatogenesis": High body temperature causes problems. Sperm cells
can’t develop at normal body temperatures. Alternatives: Develop at night when body
temperature may drop. Delay final development until storage in cooler sac or pouch near
cloaca.
يجبمعرفةالدورالحيويالذيتلعبهالكياسالهوائيةالبطنيةفيالتأقلموخفضدرجةالحرارةالجسميةأثناءتكوين
الحيوانات.المنويه
Sperm Output: Millions to billions/copulation.
Sperm viability: Sperm cells remain in oviduct 2-3 wks after mating. At the 10th
day 50% ability
and at the 19th
day 15% ability.
Female reproductive anatomy: Left sided ovary and oviduct are the only active one but
the right ovary and oviduct atrophied.
Ovary: Ovary may contain thousands of ovarian follicles. Only few per year mature into ova.
Rapid growth through addition of fat, protein food (yolk) probably from liver
Oviduct has five parts: Infundibulum “Funnel”, Magnum, Isthmus, Uterus and Vagina.
14. Infundibulum “Funnel”: Receives the yolk from the ovary. Sperm cells received from the
rooster are stored here. It captures released ova, 2 ova released simultaneously produce
“double-yoked” egg. Ovum spends ~20 minutes here in chicken.
Magnum: The largest region that secretes layers of albumen (egg-white). It takes 3 hrs for the
thick white to be placed around the yolk in the magnum. Ovum spends 4 hrs here in chicken.
Isthmus: the yolk and thick white then moves to the Isthmus, 2 shell membranes are added;
Produces shell membranes. Flexible keratin, Ovum spends 1.25 hrs here in chicken.
Uterus: thin white colored producing the outer shell of egg, egg remains in the uterus about 20
hrs in chicken. Shell gland produces calcium carbonate shell. Pigment glands apply colors.
Vagina: 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. Lined with mucous glands and muscular to aid egg-
laying. Ovum spends very brief time here in chicken - just passing through.
One egg takes 25-27 hours for a chicken to produce one egg.
Hormones, light and nutritional programs influencing in egg production.
Fertilization Process: Male places the sperm into the female oviduct. Male papillae deposits
sperm in cloacal wall of female. Sperm move up the oviduct to the funnel where the egg is
fertilized "at the ampoula". Sperm cells remain in oviduct 2-3 wks after mating. Sperm have full
fertilizing ability for about 6 days after then ability of sperm to fertilize egg decreased. 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 "Oviparous".
Incubation: keeping eggs at right temperature and humidity for hatching. Hen does this by
sitting on eggs. Commercial hatcheries use mechanical incubators. Incubation of chickens is 21
days. Temperature 38-39 C. Relative humidity 60% for the first 18 days. RH 70% for the last 3
days. 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.
15. The avian Eyes:
The eyes should be clear with dark black pupils surrounded by a colored iris. The color of
the iris varies with the breed and age of the bird, but in general is steel-grey in chicks and
poults. In adult broilers, layers, and broiler breeders the iris is yellow-orange; but brown
in adult turkeys.
The avian Ears:
The ear in a bird is covered with fine feathers and is a small opening located on the side of
the head. The eye should be a bright yellow-orange in color and free of discharges.
The avian nervous system
16. The avian body temperature:
Normal for chickens are 41-42 C. Chickens are comfortable up to 25 C with 65% relative
humidity. Birds keep cool through the comb and by respiration – panting and spreading their
wings when too hot. Heat management is more important for chicks than for older birds.
هنايجبالتذكرةباللياتالكلسيكيةأوالعتياديةواللياتالفوقأعتياديةلتنظيمدرجةالحرارةالجسميةمعدرجة
الحرارةالجويةكمايجبالتذكرةبعمليةالحتباسالحراريفي.الطيور
The avian life span:
Fast heartbeat and high rate of metabolism limits life span. Chickens living to 10-15 years are
the exception. Broiler chickens go to slaughter at a very early age about 7 wks. Commercial egg
producers replace birds at about 60 wk of age. Commercial breeders' producers replace birds at
about 65-70 wk of age.
Serous & mucous membranes and differences between them.
Serous membranes are the covering while the mucous membranes are the lining membranes.
Mucous membranes contain mucous or goblet cells while serous do not. Serous membranes are
not suffering from catarrhal inflammation.
Examples of serous membranes are: pericardium, pleura, meanings, peritoneum, Glisson's
capsule of liver, synovial sheath and periostum.
Examples of mucous membranes are: mucous membrane lining the canalized systems
"digestive, respiratory, urinary and reproductive".
Comparison of scientific terms to common poultry plant terms:
Scientific Term Plant Term
Uropygial gland Oil gland, preen gland, oil bag
Stifle joint Knee joint
Esophagus Gullet, goozle
Ingluvies Crop, craw
Cloacal bursa (Bursa of Fabricius) Rosebud, flower
17. Ceca Blind guts
Trachea Windpipe
Syrinx Voice box
Lungs Lights
Pericardium Heart sac
Tibia and fibula Drumstick
Femur thigh bone Thigh
Pubis Pin bone
Clavicles (fused) Wishbone
Sternum keel Breast bone
Fused metacarpals Wing tip
Radius and ulna Wing portion
Humerus Peg leg
Avian behavior: Chickens have a well-developed social order (peck order) and birds at
the bottom may become culls if there is insufficient feed or water space. Close confinement
of birds in cages may aggravate this problem. If birds are mixed, considerable fighting to
re-establish the peck order may occur. Temperament is a breed characteristic. Leghorns
are more flighty than White Rocks. Birds are structurally very different from mammals,
and nowhere is this difference so striking as it is in the arrangements of their digestive
systems. The evolutionary lineage of modern birds is in dispute, but one widely held
theory, for which there is some considerable support, holds that they're more or less direct
descendants of the dinosaurs. As you might expect, therefore, there's not much similarity
to the typical mammalian pattern; furthermore, the avian digestive tract is suited to the
peculiarities of bird life. The central fact of being a bird is that everyone wants to eat you.
With a few notable exceptions, birds are on nearly every predator's menu. Consequently,
their anatomy reflects adaptations for evasion and escape. To be able to "eat and run" (or
"eat and fly") has real selective value, so birds have evolved a digestive system that
permits them to "eat now, digest later," after they get away from whatever is chasing them.
طرقتربيةالدواجن
تربىالدواجنبطرقمتعددةيمكنإجمالهاكالتي:
1-التربيةالفرديةSmall scale production:وهذههيالطريقةالوحيدةللفلحوالريفيينلتربيةعددمحدودمن
الطيورفوقأسطحالمنازلوتتميزبعدمالدقةفيمعظمالمورالخاصةبالتربيةوعليرأسهانظمالتغذيةالعلمية
للدواجنوطرقالوقايةوالسيطرةضدالمراضويمثلهذاالنوعمنالتربيةحوالي20%منالنتاجالداجنيفي
.مصر
2-التربيةالنصفمكثفةSemi-intensive production:يتمتربيةعددمنالطيوركبيرنسبياوتتمفيعنابر
مخصصةلذلكويراعىفيهابعضامنسبلالتربيةالحديثةفيمايخصنظمالتغذيةالعلميةللدواجنوطرقالوقاية
والسيطرةضدالمراضوهذاالنمطمنالتربيةهوالغالبفيبلدناالحبيبمصرويمثلهذاالنوعمنالتربيةحوالي
70%منالنتاجالداجنيفي.مصر
3-التربيةالمكثفةproduction = Fully Integrated systems Intensive = Massوهذاالنوعمنالتربية
يطلقعليهالنظامالمتكاملحيثيشملتربيةالمهاتوالتسمينالناتجمنهاكمايشملمصانعأعلفومعامل
تشخيصية..وفيهنجدأنوحدةالتربيةيربيفيهاعددكبيرمنالطيورفىعنابرمخصصةلذلكويراعىفيهاكلسبل