Lecture 1

Question 1

List the unique features of a mare ovary

Answer 1

• “inside out”
• Ovulation occurs only from the ovulation fossa
• Follicles can be palpated but no a CL

Question 2

What cycle does the mare have

Answer 2

Seasonally polyesters

Question 3

Puberty of mare

Answer 3

14 months

Question 4

Puberty of stallion

Answer 4

18 months

Question 5

Average oestrous cycle

Answer 5

21 - 22 days

Question 6

Average oestrus

Answer 6

7 days

Question 7

Length of diestrus

Answer 7

14-16 days

Question 8

Timing of ovulation

Answer 8

1-2 days before the end of oestrus

Question 9

Ovulatory follicle diameter

Answer 9

35-70mm

Question 10

How may waves of follicular development per cycle

Answer 10

1-2

Question 11

When is PGF2a released

Answer 11

13-16 days post ovulation

Question 12

When is breeding season in the Southern Hemisphere

Answer 12

sep - march

Question 13

When is breeding season in the northern hemisphere

Answer 13

April - oct

Question 14

What are the physiological changes associated with seasonality in mares

Answer 14

Increased day length -> Increased GnRH -> increased FSH secretion -> Initiation of follicle development -> follicles secrete little oestrogen -> little LH secretion -> follicles fail to ovulate -> normal follicle develops -> this follicle able to secrete sufficient oestrogen to stimulate an LH surge -> ovulation occurs

Question 15

What in vernal transition (Autumn or Spring transition)

Answer 15

Transition from anoestrus to undergoing regular oestrous cycles, or transition from undergoing regular cycles to anoestrus
They transition from anoestrus to cycling they often shed in winter

Question 16

Ventral transition: when do follicles not ovulate

Answer 16

During the transitional period

Question 17

What are the signs used to stage the oestrous cycle

Answer 17

1. Behaviour
2. Characteristics of the cervix
3. Characteristics of the ovary
4. Characteristics of the uterus

Question 18

What is the teasing score

Answer 18

Should be recorded during the breeding season to assist with breeding management

Question 19

Number the teasing scores and their meaning

Answer 19

0 - non-receptivity (ears back, kicks at stallion, moves away)
1 - mare is passive (no signs of oestrus but doesn’t kick, common in winter anoestrus
2- mare stands, but may be restless; winks without urinating
3 - mare stands, lifts tail, shows interest in stallion, winks and immediately passes small amount of urine
4 - as for 3, but mare also squats and urinates in continuous stream

Question 20

What does the cervix feel like in dieostrus

Answer 20

Firm, tubular

Question 21

What does the cervix feel like in oestrus

Answer 21

Progressively softer

Question 22

What does the cervix feel like close to ovulation

Answer 22

Soft, wide or barely palpable close to ovulation

Question 23

Score 1 of the cervix

Answer 23

High, dry, tight (dioestrus)

Question 24

Score 2 of the cervix

Answer 24

Drooping ( early oestrus)

Question 25

Score 3 of the cervix

Answer 25

Hanging - dorsal and ventral surfaces soft and extend towards vagina, dorsal surge not fully flat or in contact with vagina

Question 26

Score 4 of the cervix

Answer 26

Lying - dorsal and ventral surfaces of cervix tent to lie flat on the floor of the vagina

Question 27

What size are the ovaries

Answer 27

> 35mm

Question 28

How to detect a soft follicle

Answer 28

by palpation and associated with flattening of wall of follicle with apposition of ultrasound probe

Question 29

What is the uterus tone in oestrus

Answer 29

More flaccid, oedematous

Question 30

what is the uterus tone in dioestrus

Answer 30

Increased in tone and feels more tubular

Question 31

What is the uterus echogenicity in oestrus

Answer 31

Presence of oedema

Question 32

What is the uterus echogenicity in dioestrus

Answer 32

Uniform echogenicity

Question 33

What is the oedema score

Answer 33

0 - none 1 - slight. small amount of oedema detectable 2 - moderate oedema throughout the uterus 3 - Heavy. Obvious oedema through the uterus - may indicate heavy uterine infection