26 Stallion Breeding Soundness Exam

Inner lamina of preputial fold (pocket between the penis and the prepuce, but part of the prepuce)

What is 1?

Free part of the penis (actual penis skin)

What is 2?

Attachment of the inner lamina of the preputial fold to the penis

What is 3?

Internal lamina of the external fold of the prepuce

What is 4?

Urethral sinus (where the "bean" would be located)

What is 1?

Fossa glandis

What is 2?

Urethra process

What is 3?

1. reproductive history

2. physical exam

3. venereal diseases

4. eval. of internal and external genitalia

5. bacterial cultures

6. sexual behavior

7. collection of semen

8. semen eval. = motility, morphology, concentration, volume, longevity

Name some parts of a routine BSE

Estimate the stallion's present fertility

What is the purpose of a BSE in stallions?

1. abnormalities like lameness and back pain may affect mating ability

2. do they have heritable problems like wobblers, cryptorchidism, and parrot mouth

Why is a general physical exam important for a stallion BSE?

Annually

How often do you need to test stallion serum for equine arteritis virus?

Vaccinate stallion only

If the stallion serum is negative for equine arteritis virus, what do you do?

Test the mares:

if the mares are positive = DONT vaccinate

if the mares are negative = VACCINATE PRIOR to breeding

If the stallion serum is positive for equine arteritis virus and the semen is ALSO positive, what do you do?

30 days before all the way to 10 days after parturition

When can you palpate for presence of 2 testicles in males?

Cranial to caudal direction:

Head of epididymis cranial, tail of epididymis caudal

What is the normal testicle orientation in stallions?

Daily sperm output

What is testicular size correlated with in stallions?

Total scrotal width = taken with calipers (put both testicles side by side and measure across, typically 100 mm)

How do you determine testicular size in stallions?

5 years of age

When is sexual maturity in stallions?

Laceration

What is this penis abnormality?

Squamous cell carcinoma

What is this penis abnormality?

Melanoma

What is this penis abnormality?

Balanitis

What is this penis abnormality?

Habronema (squamous cell carcinoma differential, culture)

What is this penis abnormality?

Prepuce, urethral fossa, urethra (pre and post ejaculation), semen, glans

What do you swab on the penis for aerobic equine culture?

Stallions

Stallions or mares are asymptomatic carriers of most venereal organisms

b. Taylorella equigenitalis (this is CEM)

c. B hemolytic Streptococcus

e. Klebsiella pneumonia

f. Pseudomonas aeruginosa

If you culture an equine penis, presence of WHAT ORGANISMS automatically causes them to fail the BSE?

a. proteus spp.

b. Taylorella equigenitalis

c. B hemolytic Streptococcus

d. Aerobacter spp.

e. Klebsiella pneumonia

f. Pseudomonas aeruginosa

Ampulla

What accessory sex gland is pink in stallions?

Vesicular glands

What accessory sex gland is yellow in stallions?

Bulbourethral gland

What accessory sex gland is orange in stallions?

Lobe of prostate gland

What accessory sex gland is blue in stallions?

Missouri, Colorado, Roanoke

What are the 3 types of AVs (artifical vaginas) for semen collection in stallions?

Missouri

AVs are a very common way to collect semen in horses. Which type of AV is this?

Colorado

AVs are a very common way to collect semen in horses. Which type of AV is this?

Roanoke

AVs are a very common way to collect semen in horses. Which type of AV is this?

Temperature AND pressure

What conditions are stallions sensitive to in their artificial vagina?

a. lighter weight

d. can manipulate the stallion's penis easier

Select the advantages of a Missouri AV:

a. lighter weight

b. heavier but retains temperature better

c. will fit inside phantom so stallion can service like a mare

d. can manipulate the stallion's penis easier

b. heavier but retains temperature better

c. will fit inside phantom so stallion can service like a mare

Select the advantages of a Colorado AV:

a. lighter weight

b. heavier but retains temperature better

c. will fit inside phantom so stallion can service like a mare

d. can manipulate the stallion's penis easier

a. lighter weight

Select the advantages of a Roanoke AV:

a. lighter weight

b. heavier but retains temperature better

c. will fit inside phantom so stallion can service like a mare

d. can manipulate the stallion's penis easier

Roanoke

Which AV has the disadvantage of having to wait until the bell of the penis goes down until being able to remove?

Colorado

Which AV has the disadvantage of being difficult to manipulate the stallion's penis within the AV?

Missouri

Which AV has the disadvantage of not being able to hold temperature well?

Phantoms

What are these?

Colorado is the only one

Which is the "in line" AV with the phantom? (where the penis goes right into the phantom because the AV is in there)

To smell pheromones from the urine to determine where she is in her cycle

Why do stallions do the Flehmen response as a reproductive behavior?

Penis ring, whipping

Name a few things that may "negatively reinforce" a stallion to NOT breed or show reproductive behavior?

The bell of the penis (where even a small scratch can cause significant bloodiness)

What is this?

1. pre-sperm

2. sperm-rich (WANT THIS)

3. gel (REMOVE THIS)

What are the ejaculatory fractions in stallions?

First, pre-sperm

Which ejaculatory fraction in stallions comes from the prostate?

Second, sperm-rich

Which ejaculatory fraction in stallions comes from the epididymis, ampulla, and prostate gland?

Third, gel

Which ejaculatory fraction in stallions comes from the vesicular glands or bulbourethral glands?

Events that occurred in the last 2 months

Semen or ejaculate we see today in horses actually reflects events that occurred when?

Total progressively motile morphologically normal spermatozoa

For a breeding soundness exam, what kind of spermatozoa are you looking at in stallions?

Total sperm x % progressively motile

NOT LOOKING AT MORPHOLOGICALLY NORMAL for breeding

To know how much sperm to breed with, what kind of spermatozoa are you looking at in stallions?

Positive correlation

How is sperm motility correlated with fertilizing ability in stallions?

OVER 60%

What do you need sperm motility to be in stallions?

OVER 60%

What do you need sperm morphology to be in stallions?

FALSE

TRUE OR FALSE: equine spermatozoa head with an abaxial attachment to the midpiece is considered an abnormality

Large

Abaxial head attachment to the midpiece in equine spermatozoa results in large or small circling of spermatozoa?

Hemacytometer

What is the gold standard for counting sperm concentration in stallions?

eosin-nigrosin stain (Hancock)

Which stain to look at sperm morphology in stallions stains the BACKGROUND, not the cell:

diff quick or eosin-nigrosin stain (Hancock)

Diff quick

Which stain to look at sperm morphology in stallions stains the CELL ITSELF, to evaluate what round cells are present:

diff quick or eosin-nigrosin stain (Hancock)

Diff quick = BE CONCERNED if you see these round cells

What is this stain and are you concerned if you see these in spermatozoa?

eosin-nigrosin stain (hancock)

Is this diff quick or eosin-nigrosin stain (hancock)

Look at alkaline phosphatase. If over 3,000 U/L, this means the stallion had a true ejaculate

Biochemical testing is an OPTIONAL part of the stallion BSE. Why would you do it and what can it tell you?

1 x 10^9 = 1 billion

What is the normospermic number (progressively motile, morphologically normal sperm) you are looking for in stallions?

Impregnate 75% of a full book of mares in less than 2 normal estrous cycles with fresh semen

In order to be a satisfactory breeder, how many does a stallion have to impregnate in a full book of mares?

40 mares by natural cover OR 120 mares by AI

A stallion must impregnate 75% of a full book of mares in less than 2 normal estrous cycles with fresh semen in order to be considered a satisfactory breeder. What is a full book?

Failure to pass 1 to 2 parameters

How many failures does a stallion have to have for him to be considered an unsatisfactory breeder?

In 60 days

If a stallion fails and is considered a questionable breeder, when can you reevaluate him?

A stallion under 4 years old (because remember they reach sexual maturity at 5 years)

A stallion under WHAT AGE that fails the breeding soundness exam should definitely be re-evaluated?

500 million (500 x 10^6) progressively motile spermatozoa

How much spermatozoa do you need for a breeding dose?

60 mL x 120 million (10 x 10^6) per mL gives you a total of 7.2 billion spermatozoa

7.2 billion (7.2 x 10^9) x 60% aka 0.6 progressively motile gives you 4.32 billion progressively motile sperm available for breeding.

But because we need to pass the BSE, we go a step further

4.32 billion (4.32 x 10^9) x 70% aka 0.7 morphologically normal gives you 3.02 billion progressively motile morphologically normal sperm

Which brings us back to the question, does he pass the BSE? = YES

You have 60 mL of raw semen with a concentration of 120 million spermatozoa per mL. 60% are progressively motile, 70% are morphologically normal. How many progressively motile, morphologically normal spermatozoa would pass the BSE?

60 mL x 120 million (10 x 10^6) per mL gives you a total of 7.2 billion spermatozoa

7.2 billion (7.2 x 10^9) x 60% aka 0.6 progressively motile gives you 4.32 billion progressively motile sperm available for breeding.

Remember 500 million progressively motile sperm are needed in a breeding dose, so:

4.32 billion (4.32 x 10^9) / 500 million (500 x 10^6) = 8.64 mares

Meaning 8 mares can be bred with this semen collection

You have 60 mL of raw semen with a concentration of 120 million spermatozoa per mL. 60% are progressively motile, 70% are morphologically normal. How many progressively motile sperm are there (what is the breeding dose) and how many mares can be bred?