Equine Breeding Management

Question 1

In regards to equine breeding seasons:

Season starts in the N hemisphere on _____

and starts in the S. hemisphere on ______

Answer 1

Northern Hemisphere: Feb 15th

Southern Hemisphere: Aug 15th

Question 2

What are the 4 factors that can maximize

chances of pregnancy in mares?

Answer 2

4 factors to maximize our chances:

good management, good timing, clean mare, good semen

Question 3

In the horse industry

ALL HORSES HAVE A UNIVERSAL BIRTHDAY ON _______ regardless of when they are born.

Answer 3

JANUARY 1ST

Question 4

According to the horse industry:

If a horse is born on Dec 21, 2016

when do they turn 1 year old?

Answer 4

January 1, 2017

Question 5

In the northern hemisphere,

why does the breeding season start on Feb. 15th

in particular?

Answer 5

Feb 15th is because gestation period of mare is 342-345 days

so if you breed too early, there is a chance that foal

might be born at the end of the December

(then it takes 2 days for the foal to turn “1 year”- according to the horse industry)

Question 6

When comparing older mares to younger mares:

older mares start cycling _____ in the year

and

older mares come into heat _______in the season than younger mares

Answer 6

later, later!!

Question 7

Mares Pregnant divided by the # Mares Bred

equals

Answer 7

Pregnancy rate

Question 8

In regards to pregnancy rate:

You want ____% of mares pregnant AFTER first cycle!!!!

You want to have a commutative pregnancy rate of ____% at end of breeding season

(season ending June 30/July 15th)

Answer 8

60% pregnancy rate after 1st cycle

90% pregnancy rate at end of breeding season

Question 9

Thoroughbreds can bred between 2x to 4x per day with the limiting factor being ______

Answer 9

libido!

Question 10

________ need to be bred under live cover,

This breed DOES NOT ACCEPT AI!

Answer 10

Thoroughbreds!

Question 11

You see a “cartwheel” on ultrasound of the uterus.

What ENDOMETRIAL EDEMA GRADE is this?

Answer 11

ENDOMETRIAL EDEMA GRADE 4

Question 12

ENDOMETRIAL EDEMA

GRADE _____ = HYPER-EDEMA (aka abnormal uterine edema)

Answer 12

GRADE 5

Question 13

Mares that ovulate with _____ edema

24 - 48 hours post-breeding

will have a higher pregnancy rate

Answer 13

low

Question 14

What are the 2 methods of breeding mares?

Answer 14

Natural Cover

Artificial Insemination

Question 15

In regards to artificial insemination:

Fresh Semen – used ____hours between collection and insemination

Cooled shipped semen – collected ______hours before AI

Frozen Semen – useable FOREVER!

Answer 15

Fresh semen: 1 - 2 hours between collection and insemination

Cooled Shipped semen: collected 24 - 48h before AI

Question 16

In regards to types of semen used for AI:

_______semen has the lowest survival time, we need to breed very close to ovulation when using it

Answer 16

Frozen

Question 17

There is no question that breeding prior to ______ results in higher pregnancy rates

Answer 17

ovulation

Question 18

How many hours prior to ovulation should you

breed naturally?

Answer 18

48 - 72 hours

Question 19

How many hours prior to ovulation should you

breed using FRESH semen

Answer 19

<48 hours

Question 20

How many hours prior to ovulation should you

breed using FRESH COOLED semen?

Answer 20

24 - 36 hours

Question 21

How many hours prior to ovulation should you

breed using FROZEN semen?

Answer 21

<12 hours

Question 22

IF BRED THE DAY AFTER OVULATION

pregnancy rate is ____%

which tells you the limiting factor in breeding is the _______

not lifespan of the _____.

Answer 22

IF BRED THE DAY AFTER OVULATION

pregnancy rate is 6%

which tells you the limiting factor in breeding is the lifespan of the oocyte

not lifespan of the sperm.

Question 23

What is the lifespan of the oocyte (how long is the egg viable?)

Answer 23

12 hours only!

Question 24

Mares are very good at storing sperm; they store sperm in the ___________

Answer 24

isthmus of the oviduct

Question 25

What is the fertility rate in a horse with adequate semen quality in natural cover breeding and fresh AI semen?

Answer 25

\>60%

Question 26

What is the fertility rate in a horse with adequate semen quality using cooled semen AI?

Answer 26

\>50%

Question 27

What is the fertility rate in a horse with adequate semen quality using frozen semen AI?

Answer 27

\>40%

Question 28

AI if done properly, in most cases will ______ the fertility of the mare and/or the stallion

Answer 28

enhance

Question 29

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

Answer 29

FALSE!!

Question 30

Because Thoroughbreds cannot be bred AI, what 2 methods are used as a loophole to this roll

Answer 30

MINIMUM CONTAMINATION TECHNIQUE (putting extender into uterus before breeding) REINFORCING THE BREEDING (scoop up semen from vagina after breeding and get post ejaculatory drops put in extender and put into uterus with pipette)

Question 31

The standard place for semen deposition in AI is the

Answer 31

uterine body

Question 32

What are the 4 components of proper AI?

Answer 32

Deposition of good quality semen **0.5 – 1.0 x 10^6** Into the uterus of a clean mare – **culture swab (-) for bacT** At the right time **(0-24 hrs pre ovulation)** The standard place for semen deposition is the **uterine body**

Question 33

The main factor contributing to sperm migration to the oviduct is \_\_\_\_\_\_\_\_\_\_

Answer 33

uterine contractility

Question 34

In natural mating \_\_\_\_\_\_sperm are deposited in the uterus

Answer 34

2-15 billion

Question 35

By ________ after breeding/AI the sperm are in the oviduct

Answer 35

30 min – 4 hours

Question 36

In regards to sperm transport: Maximal colonization post insemination appears to be achieved by \_\_\_\_\_. Important because egg is only viable for 12 hours. This is when we can start doing 2\* treatments.

Answer 36

4 HOURS

Question 37

Which group of mares would have the best seasonal pregnancy rate? Place in order from **best to worst** rate: Barren, old maiden, young maiden, foaling mare

Answer 37

Young maiden mares \> foaling mares \> barren mares \> old maiden mares (mare not bred but \>8yr)

Question 38

What are the benefits of the Deep Horn Insemination Technique which uses a flexible pipette to deposit semen in uterine horn/close to uterotubal junction

Answer 38

Reduces inseminate volume, sperm numbers, uterine-sperm time contact and thus uterine inflammation which increases pregnancy rates