Rewproductive Physiology in the Mare

Question 1

How is puberty defined and when is it in mares?

Answer 1

12-24 months –> first ovulation

Question 2

How is puberty defined and when is it in mares?

Answer 2

12-24 months –> first ovulation

Question 3

How is puberty defined and when is it in mares?

Answer 3

12-24 months –> first ovulation

Question 4

Normal gestation in the mare

Answer 4

340 days average (320-365)

Question 5

What is the placentation of a mare

Answer 5

diffuse, epitheliochorial (least invasive), microcotyledonary

Question 6

When do endometrial cups show up and what do they do?

Answer 6

35-120 days

they are more invasive (syndesmochorial) and secrete eCG

Question 7

How old do mares typically stop cycling?

Answer 7

24 yo

Question 8

How long is the estrous cycle?

Answer 8

21-22 d

Question 9

how long is estrus?

Answer 9

5-7 days

Question 10

When is anestrus in the mare?

Answer 10

november to january

Question 11

When is the physiological breeding season?

Answer 11

A/M to S/O

Question 12

Normal gestation in the mare

Answer 12

340 days average (320-365)

Question 13

Spring transition is also

Answer 13

vernal transition

Question 14

When do endometrial cups show up and what do they do?

Answer 14

35-120 days

they are more invasive (syndesmochorial) and secrete eCG

Question 15

How old do mares typically stop cycling?

Answer 15

24 yo

Question 16

how many days of artificial light are required for ovulation

Answer 16

60 days

Question 17

how long is estrus?

Answer 17

5-7 days

Question 18

When is anestrus in the mare?

Answer 18

november to january

Question 19

When is the physiological breeding season?

Answer 19

A/M to S/O

Question 20

What is the physiological process of the mare’s heat?

Answer 20

receptors in eye –> pinneal gland –> more light=decreased melatonin –> increases GnRH from HT to Pit –> increases FSH, LH in circulation –> goes to the ovaries and testes

Question 21

Normal gestation in the mare

Answer 21

340 days average (320-365)

Question 22

What is the placentation of a mare

Answer 22

diffuse, epitheliochorial (least invasive), microcotyledonary

Question 23

When do endometrial cups show up and what do they do?

Answer 23

35-120 days

they are more invasive (syndesmochorial) and secrete eCG

Question 24

How old do mares typically stop cycling?

Answer 24

24 yo

Question 25

How long is the estrous cycle?

Answer 25

21-22 d

Question 26

how long is estrus?

Answer 26

5-7 days

Question 27

When is anestrus in the mare?

Answer 27

november to january

Question 28

When is the physiological breeding season?

Answer 28

A/M to S/O

Question 29

What is the physiological process of the mare's heat?

Answer 29

receptors in eye --> pinneal gland --> more light=decreased melatonin --> increases GnRH from HT to Pit --> increases FSH, LH in circulation --> goes to the ovaries and testes

Question 30

What happens in fall transition in mares?

Answer 30

less light --> longer follicular waves --> delayed ovulation --> big follicles will rise up and then go down again and so on.. THere will be 3-5 waves with/wo follicles, then the GnRH will fall enough to not have waves.

Question 31

What happens in spring transtition in mares?

Answer 31

increased light = increased GnRH, but this happens slowly and the follicles start to grow and grow and more waves until the LH surge it high enough to ovulate

Question 32

Spring transition is also

Answer 32

vernal transition

Question 33

What are the characteristics of the anestrus uterus, cervix and vagina, and behaviour and follicular actiivty

Answer 33

pale dry vagina flaccid uterus atonic cervix no interest in males

Question 34

How do early vs. later foalings differ

Answer 34

early will have foaling heat, then back to transitional. Later will go straight into normal cyclicity

Question 35

how many days of artificial light are required for ovulation

Answer 35

60 days

Question 36

What are the characteristics of an in estrus mare?

Answer 36

``` soft uterine and cerv tone large ovaries developing follicles uterine edema (wagon wheel), regressing CLs and foll growth VERY receptive ```

Question 37

What are the characteristics of a mare in diestrus

Answer 37

``` variable ovary size increased uterine and cervical tone no edema in uterus CLs present In general easier to palpate things Reject violently ```