Equine Breeding Management

Question 1

Treatment with ____ is the most common management tool in equine reproduction.

Answer 1

Prostaglandin

Question 2

The interval between prostaglandin injection and ovulation is determined by…

Answer 2

the size of the follicle at the time of treatment

Question 3

Mares with (small/large) follicles can have unexpected ovulations if the mare is not examined prior to treatment.

Answer 3

large

Question 4

Universal birthday for horses?

Answer 4

January 1st.

Question 5

Breeding Management factors (ie MF, SF) are (multiplicative/additive)?

Answer 5

multiplicative.

Question 6

Repro Management Keys to obtain good fertility:

1.
2.
3.
4.
5.
6.

Answer 6

1. Normality of the estrous cycle
2. Pre and Post breeding therapies
3. Timing of insemination
4. Place of insemination
5. Number of sperm in the inseminate
6. Volume of the inseminate

Question 7

Formula for Pregnancy Rate?

Answer 7

of Mares Pregnant divided by # of Mares Bred

Question 8

Target Pregnancy Rate:

1. Per Cycle (14-16 days)?
2. Per season?

Answer 8

1. > 60%

2. > 90%

Question 9

What equine breed can breed between 2 to 4 times / day with the only limiting factor being libido?

Answer 9

TBs

Question 10

What regimen is recommended to get the maximum number of sperm collected from stallions via AI?

Answer 10

Take every other day throughout the season

Question 11

Uterine Edema:

1. First appears when?
2. Starts to decrease when?
3. Most mares will ovulate with a (low/high) degree of endometrial edema?

Answer 11

1. early estrus
2. as mare approaches ovulation
3. low

Question 12

Describe a Grade 2 Endometrial Edema:

1. Cervix?
2. Follicle size?
3. Folds?

Answer 12

1. relaxed and edematous = fishbone
2. 30-35 mm or 40+ mm preovulatory
3. some folds easily observed with yperechoic centers in folds

Question 13

What distinguishes a Grade 4 endometrial edema?

Answer 13

The folds! They are thicker, with a hypoechoic center and hyperechoic wall. They are more prominent at the uterine body but maintain architecture with a “cart wheel
appearance

Question 14

Describe a Grade 5 endometrial edema

1. folds?
2. surface area?
3. follicles?

Answer 14

1. VERY THICK endometrial folds cause loss of normal u/s architecture
2. Increased
3. Follicles variable, but often are preovulatory or recently ovulated

Question 15

Two Broad kinds of Breeding Methods:

1.

2.

Answer 15

1. Natural cover

2. AI

Question 16

1. Two kinds of natural cover breeding methods?

2. Three kinds of AI breeding methods?

Answer 16

1. Pasture breeding and Hand breeding

2. Fresh semen, cool shipped semen, frozen semen

Question 17

Breeding method: Inseminate how long before ovulation?

1. For natural breeding?
2. For fresh semen?
3. For fresh cooled semen?
4. For frozen semen?

Answer 17

1. 72-48 hours.
2. < 48 hours
3. 24 - < 36 hours
4. < 12 hours

Question 18

What breed cannot do AI?

Answer 18

TBs

Question 19

Fertility Rates per cycle in horses wit hadequate semen quality:

1. Natural cover?
2. Fresh AI?
3. Cooled AI?
4. Frozen AI?

Answer 19

1. > 60%
2. > 60%
3. > 50%
4. > 40%

Question 20

Timing of Breeding depends on what three factors?

1. 2.
   3.

Answer 20

1. Type of semen used
2. Susceptibility of the mare to infections or inability to evacuate uterine fluid
3. Proximity of AI to ovulation

Question 21

T/F: Natural breeding is a cheap alternative to AI

Answer 21

FALSE

Question 22

Preparation of the mare for breeding:

1.
2.
3.
4.

Answer 22

1. Bandage tail
2. Wash and rinse vulva and perineum
3. Dry washed area
4. Proper mare restraint

Question 23

Definition of PROPER artifical insemination:

Answer 23

Deposition of good quality semen (.5-1.0 x 10^9) into the uterus of a clean mare at the right time (0-24 hours pre-ovulation) via the uterine body

Question 24

Advantages of AI;

1.
2.
3.
4.
5.

Answer 24

1. Maximize efficiency of stallion usage
2. Increase genetic pool due to increased availability of stallions
3. More regular evaluation of stallion semen
4. Reduce risk of sexually transmittable diseases
5. Increases safety of animals and handlers

Question 25

Sperm transport: 1. Natural mating has how many sperm deposited in the uterus? 2. How long to get in the oviduct? How long do they stay there?

Answer 25

1. 2-15 billion | 2. .5-4 hours. Can stay for hours or days

Question 26

Sperm transport: 1. _____ is responsible for eliminating excess fluid from the uterus. 2. Maximal colonization appears to be achieved after how long?

Answer 26

1. myometrial contractions | 2. 4 hours

Question 27

Put these types of mares in order of least to most fertile: 1. Mares with foal 2. Barren mares 3. Mares > 8 years old 4. Mares < 7 years old

Answer 27

1. Maiden Mares > 8 years old 2. Mares with foal 3. Barren mares 4. Maiden mares < 7 years old

Question 28

T/F: Evidence has suggested 2x AI pre and post ovulation has a better result than a single AI

Answer 28

True

Question 29

Advantages of Deep Horn Semen deposition: ``` 1. 2. 3. 4. 5. 6. ```

Answer 29

1. Increase the # of mares bred per ejaculate 2. Maximize frozen semen usage 3. Increase the efficiency of sexed sperm AI 4. Utilize stallions with sub-optimal semen quality 5. Reduce the incidence of post-breeding endometritis 6. Increase fertility in some mares

Question 30

What are the three assisted repro techniques used when a mare does not become pregnant after being bred with good semen under excellent management?

Answer 30

1. ICSI - intracytoplasmic sperm injection 2. ET - embryo transfer 3. OT - oocyte transfer

Question 31

Embryo Transfer: 1. Typical donor? 2. Typical recipient? 3. How old of an embryo?

Answer 31

1. Older competition animal 2. Young healthy animal 3. 7-8 days

Question 32

Indications for Embryo Transfer: 1. 2. 3. 4.

Answer 32

1. Young mares in competition 2. Mares with severe uterine problems 3. More than one foal a year 4. Biopsy for desired outcome

Question 33

Indications for intra-cytoplasmic sperm injections (ICSI) 1. 2. 3. 4.

Answer 33

1. Old mare where it is not possible to retrieve an embryo 2. Oviductal disease 3. Mares that have died 4. Use of stallions with very limited amount of semen available.

Question 34

Describe the ICSI procedure:

Answer 34

Perform Transvaginal oocyte retrieval of severeal immature oocytes, Allow in vitro oocyte maturation. Inject a single sperm into oocyte, and culture in vitro to check for cleavage. If they reach the morula stage, freeze them or transfer them to a recipient

Question 35

Indications for Oocyte transfer: 1. 2. 3.

Answer 35

1. Old mares where it is not possible to retrieve an embryo 2. Oviductal disease 3. Mares with unexplained infertility

Question 36

Describe the oocyte transfer procedure

Answer 36

Perform transvaginal aspiration of a mature oocyte, and aspirate an oocyte from recipient. Transfer the oocyte into the oviduct of the previously bred recipient mare, and let it carry to pregnancy