8- Fertility and breeding time in female Flashcards
What are the classical signs of oestrus in female
Stands to be mated by the male
What hormone drives oestrus
increasing oestradiol (fall in ,progesterone prior- except in dog )
T/F oestrus predicts the time of ovulation
False
How long does oocytes live once released
12-24 hours except in dog which releases immature oocytes
What is the fertilisation period
The time when oocytes are available to be fertilised by sperm (in majority of species this is immediately after ovulation- not in the bitch)
What is the fertile period
is the time when mating could result in pregnancy - is longer than the fertilisation period
In most species what level of progesterone indicates that oestrus will occur soon?
Low levels (not the dog- increases)
When is oestradiol at its highest point
Peak oestrus
What does GnRH surge trigger
LH surge
T/F if an animal has an active CL, they are in oestrus
False- active CL- luteal phase - progesterone is high- and ovulation can’t occur
When a follicle approaches ovulation what changes occur to its shape
Loses its turgidity and becomes irregular in shape
(Mares- follicular wall will thicken)
What is the expected size of a dominant follicle in a cow
16-20 mm- >20mm is likley to be pathology
What is the expected size of a dominant follicle in a mare
30-50mm
>50 mm could be pathology
In what animal (mare or cow), is the cervix flaccid and soft when progesterone is high (reduction in tone)
Cow
What hormone is hCG similar to
LH activity- induces ovulation
