Avian Reproduction 2

what happens in the infundibulum

• captures ovum (15 mins after ovulation)

• Site of fertilization

• contains sperm storage tubules

What is added in the magnum

Albumen (egg white)

How long does egg stay here

3 hours

function of isthmus

• Adds shell membranes

• Forms air cell

what happens in shell gland

• shell formation (98% CaCO3)

• Egg stay 19-20 hours

What is the role of the vagina

• egg transport

• site of semen deposition

• selects healthy sperm

where are sperm storage tubules located

Utero-vaginal junction

how many tubules are there

25,000

what are key egg components

• yolk

• albumen

• shell

• air cell

• chalazae

where is the cuticle

outer protective layer that blocks pores and bacteria

What is the cuticle

outer protective layer that blocks pores and bateria

why are pores important

gas exchange

where are testes located in birds

internal (unlike mammals)

What do testes produce

• sperm

• testosterone

What is the sperm pathway in birds

testes → vasa efferentia → epididymis (small) → vas deferens → cloaca

where is the sperm stored

Vas deferens (NOT epididymis)

Do birds have accessory sex glands

No (prostate, seminal vesicles)

What fluid is used instead

Lymph (from paracloacal vascular bodies)

Do chickens have a true penis

No (not intromittent)

Exception?

Ducks (have intromittent organ)

what does FSH do in males

Stimulates spermatogenesis

what does LH do

stimulates testosterone production

what does avian semen contain

• sperm

• small amount of seminal plasma

• Transparent fluid

appearance of semen

Milky white

Do avian sperm require capacitation

No

What is clutch

Consecutive day of egg laying

what is lag

time delays between eggs in a sequence

What controls oviposition timing

Ovulation +prostaglandins

When are eggs laid

morning or early afternoon

What is broodiness

Behaviour where hen stops laying and incubates eggs

What happens to progesterone

Decreases

What happens to prolactin

increases → drives brooding behaviour

What increases broodiness

• high temperature

• Low light

• isolation

• physical contact with eggs

How is broodiness controlled

• environmental management

• genetic selection

• VIP vaccination

What mating system do poultry use

polygamous

what is the male: female ratio

1:10

Why is AI used in birds

• turkey industry

• genetic selection

• conservation

What are semen extenders used for

• maintain fertility

• increase volume

• buffer bacteria

When should you avoid insemination

During or within 2 hours after oviposition