Reproduction in Poultry

Different from mammals young are not carried in the hens body develop inside a fertilized egg outside the hens body Different from mammals

Process begins with male placing the sperm into oviduct of the female male papillae deposits sperm in cloacal wall of female Process

sperm move up the oviduct to the funnel where the egg is fertilized sperm cells remain in oviduct 2-3 weeks after mating Process

Process sperm have full fertilizing ability for about 6 days after then - ability of sperm to fertilize egg is decreased Process

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. `

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.

Rooster D. Describe the poultry reproductive system Testicles Vas deferens Cloaca

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 29

Hen Ovary Magnum Vagina Infundibulum Cloaca Isthmus Uterus 30

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

2 Magnum 5 Vagina (with egg inside) 3 Isthmus 1 Infundibulum 4 Uterus 2 Magnum 5 Vagina (with egg inside) 3 Isthmus 32

Egg Processing Video Yolk Membrane Germinal Disc Yolk Air Cell Thick White Outer Shell Thick White Membrane Outer Shell Membrane Thin White 33

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) 34

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” 35

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 36

E. Describe environmental requirements to hatch chicken eggs 37

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 38

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 39

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) 40

AA A B Albumen Viscosity 1-Hold egg up to light F. Candle eggs to determine their interior and exterior quality grade. Albumen Viscosity 1-Hold egg up to light 2- Twist egg rapidly and watch to see how much the yoke moves around Egg Quality Grades: AA A B Some movement Lots of movement Little movement 41

F. Candle eggs to determine their interior and exterior quality grade. Loss Any of the following would result in the egg being graded as a “loss” -Blood/Meat Spots -Cracks or leaks in shell 42

10th day - 50% ability 19th day - 15% ability Sperm viability

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 Process

keeping eggs at the right temperature and humidity for hatching hen does this by sitting on the eggs Incubation

Incubation commercial hatcheries use mechanical incubators incubation of chickens is 21 days Incubation

Incubation temperature 102 - 103 F. RH - (relative humidity) 60% for the first 18 days RH 70% for the last 3 days Incubation

Incubation 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 Incubation

Oviduct has five parts Funnel - receives the yolk from the ovary sperm cells received from the rooster are stored here Oviduct

Magnum secretes the thick white of the egg It takes three hours for the thick white to be placed around the yolk in the magnum Magnum

Isthmus the yolk and thick white then moves to the Isthmus 2 shell membranes are added It takes 1 1/4 hours Isthmus

Uterus thin white and outer shell are added to the egg in the uterus egg remains in the uterus about 20 hours Uterus

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 Vagina

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

Ovary In the chicken only the left ovary and oviduct function the ova produced in the ovary develop into egg yolks Ovary

Reproductive Failures general physical condition of animal has an effect on the agility to reproduce Reproductive Failures

Reproductive Failures too fat or too thin may not become pregnant proper nutrition and exercise can help prevent this Reproductive Failures

Reproductive Failures animals in poor physical condition can have trouble giving birth Reproductive Failures

Infections affect reproductive organs some may prevent pregnancy others may cause a spontaneous abortion - miscarriage Infections

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

of uterus almost always fatal to embryo or fetus Infection

sexual behavior of animals is regulated by the secretion of hormones when not properly secreted the animal may not be able to reproduce Hormones

sometimes animals are treated with injected hormones

Cyst swelling containing fluid or semi solid substance may cause reproduction or breeding problems may be surgically removed depending on the value of the animal Cyst