Bird reproduction

Question 1

What change occurs to the DD in male birds during breeding season?

Answer 1

Becomes more highly coiled

Question 2

What is the seminal glomus?

Answer 2

An enlargement of the DD at the distal end–> allows sperm storage. Not all species have it, those who don’t have no sperm storage.

Question 3

In species with either no phallus or a phallus with no intromission, how does semen transfer occur?

Answer 3

-Cloaca to cloaca

Question 4

How is an erection achieved in the male bird?

Answer 4

By lymphatic system NOT vascular

Question 5

When do male birds produce the most semen?

Answer 5

At night when its cooler

Question 6

Which of the female birds ovaries are functional?

Answer 6

The left

-The right becomes activated if you remove the left.

Question 7

Describe a bird ovary

Answer 7

• Bunch of grapes appearance
• Yellow single cell which includes high concentration of lipids as lipids become the yolk
• Have no antrum, the entire follicle is filled with yolk

Question 8

Describe the hierarchy of follicles

Answer 8

• F1, F2 and F3

- F1 is the largest and will be the next to be ovulated

Question 9

What is different about avarian follicles?

Answer 9

No ZP, membrane granulosa or cumulus

Question 10

Describe the post ovulatory follicle in the bird

Answer 10

Active granulosa cells secrete non steroidal hormones (responsible for nesting behaviour)

Question 11

What do the granulosa and theca cells produce in birds?

Answer 11

Granulosa= P4

Theca=E2

Question 12

Compare the ovulation HPO feedback between mammals and birds

Answer 12

-Mammals
Hypothalamus-> GnRH-> Pituitary-> LH-> Ovary-> E2
-Birds
Hypothalamus-> GnRH-> Pituitary->LH -> F1 ovary -> P4
(so in birds it is P4 increase that is the stimulus for LH surge and ovulation)

Question 13

In birds what is the open period?

Answer 13

-Window of time for LH release

Question 14

Describe ovulation in birds

Answer 14

• F1 follicle produces enough P4(during open period) to stimulate LH surge
• Ovulation occurs
• No CL formed (no pregnancy so CL not needed)

Question 15

Where is sperm stored in female birds? And how long can it be stored?

Answer 15

• At the function of the vagina and shell gland

- 2 weeks

Question 16

Describe egg production

Answer 16

• Series of albumin coats added in concentric layers (proteins made in magnum and liver)
• Passage of egg causes release of albumin
• Inner/ outer shell membranes made in the isthmus
• Developing egg moves into the shell gland, calcium carbonate added here, then cuticle proteins added

Question 17

What stimulates release of albumin?

Answer 17

-Passage of the egg

Question 18

What is the difference between a determinate and indeterminate layer?

Answer 18

• Determinate= fixed number of eggs in a clutch

- Indeterminate= can continue to lay eggs if eggs are removed.

Question 19

How long after ovulation is an egg laid?

Answer 19

-24-36 hours

Question 20

What is the hormone that causes broody behaviour?

Answer 20

Prolactin

Question 21

How is a bird primed?

Answer 21

Must be kept in the dark, if they are exposed to light during the photosensitive period they think it is still ‘long days’. Long days stimulate gonadal regression.
-Photosensitive period= 13-17 hours after dawn.

Question 22

What are the methods for sexing pet birds?

Answer 22

• DNA via blood from claw clippings
• Surgical endoscopy of gonads
• Faecal steroids