The Mare

Question 1

Describe the breeding pattern of the mare

Answer 1

Seasonally polyoestrus, long-day breeder

Question 2

How does increasing daylength control reproductive activity?

Answer 2

• v melatonin from pineal gland
• > v inhibition of GnRH from hypothalamus
• > ^ LH/FSH from anterior pituitary

Question 3

How are the position of follicles denoted?

Answer 3

In relation to ovarian poles: Left = A-B, Right=C-D

Question 4

What are the 3 seals protecting the uterus from the environment and when are they open?

Answer 4

Cervix, vestibule and vulva

• in oestrus cervix and vulva open
• vestibule should remain closed providing correct peranal conformation

Question 5

Where should the vulva and anus lie for optimum perineal conformation?

Answer 5

vulva below ischium, anus above

Question 6

What are the 2 Tx options for sloping vulva?

Answer 6

• Caslicks vulvoplasty

- Pouret perineal resection if severe

Question 7

What do folicles secrete? What effect does this have?

Answer 7

Oestrogens
- drive seual behaviour, tract changes, LH (stimulates ovulation and leuteinisation)
Inhibin
- inhibits FSH
> when follicle collapses, withdrawal of oestrogens and inhibin

Question 8

If conception occours, when is maternal recognition of prgnancy? How does recognition occour in the horse?

Answer 8

14d after ovulation

• blastocystcapsule oestrogens prevent endometrial gland secretion of PGF2a
• otherwise, secretion of PGF2a -> withdrawal of CL and abortion

Question 9

How big should the fetal sac be at 33, 42 and 60d of pregnancy?

Answer 9

• half a hand full
• almost hand full
• more than a hand full

Question 10

How are progesterone levels maintained in the horse?

Answer 10

• secondary ovulations

Question 11

WHat can be used to identify pregnancy?

Answer 11

• chorionic girdle forms endometrial cups secrete eCG (d35-100) PD d45-95
• foetal gonads secrete oestrone sulphate d100 -> term
  PD 120-300d