Manipulating reproduction

Question 1

How is oestrus induced by use PGF2a?

Answer 1

ends luteal phase by inducing luteolysis => fall in progesterone => GnRH, LH and FSH increase => follicular development => oestradiol => oestrus 3-4 days later

Question 2

how is oestrus induced by administration for several days and then withdrawal of progesterone?

Answer 2

mimics luteal phase => withdrawal => progesterone conc falls => GnRH, LH and FSG rise => follicular development => oestradiol produced => oestrus 3-4 days later

Question 3

Why is vulval discharge in oestrus red?

Answer 3

presence of RBCs due to capillary leakage as oestradiol increases capillary permeability

Question 4

When does oestrus occur in relation to the onset of vulval swelling in bitches?

Answer 4

10-14 days after

Question 5

Label these stages of vaginal cytology

Answer 5

Question 6

Why is there an influx of WBCs in metoestrus?

Answer 6

to ‘repair’ epithelial cells that have been sloughed off in oestrus

Question 7

Label these oestrus stages based on the vaginal cytology

Answer 7

Question 8

What is the main cause of alleged infertility in bitches

Answer 8

Breeders not understanding there is a very large variation of when ovulation can occur