The Bull - MT Flashcards
Which animal, the bull or the cow, is responsible for passing on the milk production gene?
The Bull
Why are libido testing & mating ability often NOT included in a routine Bull BSE?
Difficult & time-consuming tasks
What are the 4 essential attributes a bull is required to pass a BSE?
- Freedom from disease
- Good libio
- Physically sound (sheath conformation, scrotal circumference)
- Good semen quality
Basically must be able to ID estral cows, see, eat, walk
Why is it important to test the bull’s vision during a BSE?
Bulls ID estrual cows by sight
List the Accessory Sex Glands of the Bull.
Which one often causes the most problems?
- Vesicular Glands/Seminal vesicles ⇒ causes the most problems
- Prostate
- Bulbourethral gland
- Ampulla
Where is the storage site for sperm in the bull?
The tail of the epididymis
List the important players in sperm production.
- Hypothalamus ⇒ GnRH
- Anterior pituitary ⇒ LH & FSH
- Sertoli cells (testes) ⇒ Inhibin & E2
- Leydig cells (testes)⇒ Testosterone
Why are we concerned about the
scrotal circumference of bulls?
Bulls w/ small testes:
- produce less sperm
- have earlier testicular degeneration
- produce offspring that reach puberty later
**Bulls w/large testes:**
- good sperm production
- **offspring earlier puberty **
Where is scrotal circumference measured?
At the widest part of the scrotum
What is the minimum acceptable scrotal circumference for a bull > 24 months?
34 cm
What are some ways that a vet
can collect semen from a bull?
- Rectal massage
- AV
- Electro-ejaculation
When should you place the AV on the penis when collecting semen via electro-ejaculation?
Put the AV on once you see white
(don’t collect the clear fluid)
What are the minimum standards a bull must meet in order to pass the Semen Quality exam?
- Fair gross motility (generalized oscillation)
- > 30% individual motility
- > 70% normal sperm cell morphology
What should the volume of the
spermatozoa + seminal fluid be?
1 - 6 mL
What stain is used to evaluate bull sperm?
What color is live sperm? dead sperm?
Eosin-nigrosin stain
Live = White
**Dead = Pink **
What are the 3 ways to classify sperm abnormalities?
-
Site of abnormality on the sperm
- head, midpiece or tail
-
Orgin of defect
- 1° ⇒ testes (spermatogenesis)
- 2° ⇒ epididymis
- 3° ⇒ post-ejaculation (handling, etc)
-
Effects on fertility
- Major vs. minor
- Compensable vs. uncompensable
What morphological sperm defect is commonly seen?
What does it indicate?
- Proximal protoplasmic droplets
- Scrotal injury or testicular heating
What will correct a compensable spermatic defect?
Increasig the sperm dose
What can cause orchitis in bulls?
- Brucellosis (~ 61 d)
- A. pyogenes
Define Testicular Hypoplasia.
total or partial lack of development
**of spermatogenic tissue; congenital i.e it never developed **
Define Testicular degeneration.
total or parital LOSS of spermatogenic tissue
usually following an insult e.g orchitis, fever, trauma (it was there but now its atrophied)
Define a Hydrocoele.
Accumulation of fluid btwn the
tunica vaginalis, parietalis & visceralis
Define a Hematocoele.
Accumulation of blood btwn the
tunica vaginalis, parietalis & visceralis
What is a spermatocoele?
cyst/sperm granuloma caused by leakage of sperm cells into surrounding tissue
What is a varicocoele?
dilated veins in the pampiniform plexus associated with testicular atrophy
What is the treament protocol for Fibro-papilloma that causes bleeding on the prepuce.
- Tissue vax
- Surgical removal
What term indicates a stricture of the preputial orifice that prevents the penis from being protruded?
Phimosis
What is the term that indicates an inability to withdraw the penis into the prepuce?
Paraphimosis
List possible causes of Phimosis.
- Persistent penile frenulum
- Penile hematoma
- Penile fibro-papilloma
- **Trauma to preputial opening or sx for preputial prolapse **
If you visualize swelling in front of the scrotum of a bull, what should be on your rule out list?
- Penile rupture
- Penile hematoma
List the venereal diseases that you need to be concerned about in the bull?
- Campylobacter
- Mycoplasma
- Tritrichomonas
- BVDv
- BHV-1 (IBR)
What stain is used when doing a
Live-Dead Count of spermatozoa?
Nigrosin-eosin stain
What is the minimum a number of sperm one has to count in order to perform an accurate
“Live-Dead Count”?
@ least 500 sperm
Which sperm are alive?
Which sperm are dead?
Sperm 2 is the only live sperm in this picture
(1, 3 & 4 are dead)
What can the presence of small “clots” or blood in the ejaculate be indicative of?
Seminal vesiculitis
What is the normal volume of ejaculate for a bull?
4 mL avg.
(2 - 10 mL)
What is the normal sperm concentration per ejaculate?
1250 million/mL avg.
(600 - 2800million/mL)
What is the normal total number
of sperm per ejaculate?
~ 4-5 billion
What is the exceptable progressive motility rate?
> 70% have to show progressive motility
What percentage of sperm have to have normal morphology in order to be used?
> 75% must show normal morphology
During what part of the collection/AI process are sperm the most likely to die?
During the freezing & thawing phases
Why can we dilute out bull semen and still achieve high conception rates w/ AI?
Intra-uterine insemination requires 10-100X less sperm
than natural cover
Which diseases are easily spread through bull semen?
- FMD**
- BVDv**
- IBR (BHV-1)
- IPVV
- Trichomonas
- Campylobacter fetus
- Campylobacter venerealis
- Lepto. hardjo
Which disease are unlikely to be spread through
bull semen?
- Malignant catarrhal fever
- EBL
- Johne’s Dz.
- Q-fever
- Bovine Spongiform Encephalitis (BSE)
- Akabane Dz.
When can you consider a bull disease free?
Absence of infection for 21 days
What machince can be used to “sex” sperm?
Drawbacks?
- Flow cytometry
- Not 100% reliable
- costly
- low fertility
- requires 50,000 sperm/dose
- Must perform deep uterine AI close to a follicle for good results
What type of penis do bulls have?
**Fibroelastic **
**Which is more prone to issues due to poor sheath conformation: * Bos indicus* or Bos taurus **
Bos indicus
When palpating the testes, how do you want them to feel?
Want firm and elastic, freely moveable, same size
If you see neutrophils in semen, which accessory sex gland may be affected?
Vesicular glands
What color do you want semen to be?
What could yellow semen indicate?
Grey semen?
Red/brown semen?
White/ivory
yellow - urine/pus
grey - low [sperm]
red/brown - blood
What consistency do you want semen to be? Why?
Smell?
pH?
Creamy : correlated with [sperm]
mild cholreine smell
pH +/- 6.2 (alkaline = urine)
When evaluating sperm microscopically to observe the gross motility, what are the movements you may observe, and are they good or bad?
- Rapidly swirling = very good
- Slower swirling = good
- generalized oscillation = fair
- sporadic oscillation = poor
Indiviual motility of semen must be > = __
> = 30%
Compensable or Non-compensable: Which one penetrates the zona pellucida?
Non-compensable –> sperm can penetrate ZP, but either cant cause fertility or cause EED
Venereal diseases are an important part of BSE –> which are the 2 main ones
- **Tritrichomonas foetus **
- **Campylobacter fetus subsp. veneralis **
Do bulls show C/S with veneral dz such as Tritrich or Campy?
What can you see in the cow?
How do you dx?
Bulls = No C/S
Cows may have EED (common); abortions (uncommon)
Dx: sheath scrape or sheath was in bulls –> 3 tests 3 weeks apart –> send for culture or PCR
What are the congenital issues that can affect bull fertility?
- Cryptorchid
- Testicular hypoplasia
- Segmental aplasia of epididymis (rare)
- Inguinal hernia (uncommon)
What are the acquired issues that can affect bull fertility?
- Orchitis (Brucella)
- Testicular degeneration due to orchitis, fever, trauma, stress, nutrition
- Spermatic granuloma/spermatocoele (more common in small ruminants)
What are the C/S of orchitis?
Unilateral or Bilateral?
Causes?
DDx?
C/S
- Hot, swollen, painful
Often Unilateral
Causes
- Trauma, penetrating wound, hematogenous spread
DDx
- **Brucella **
If dealing with unilateral orchitis, what may you need to do?
May need to perform a hemi-orchidectomy in valuble breeding animals ASAP to save the unafected teste before heat damages it
What is a spermatic granuloma?
Who is it more common in?
Spermatic Granuloma
- Autoimmune reaction to sperm due to their haploid state –> granuloma
- Due to leakage of sperm into th surrounding tissues sue to damage (usually epididymal damage)
More common in bucks/rams
What are the congenital issues affecting the penis that affect fertility?
Acquired?
Which is more important: congenital or acquired?
Congenital
- Persisten penile frenulum
- Rainbow or corkscrew penis
- Diphallus (rare)
**Acquired **
- **Fibropapilloma **
- Penile hematoma/broken penis
- Preputial prolapse
- Balanoposthitis
- Phimosis/Paraphimosis
Acquired conditions are very important
What is ruptured with a hematoma penis/broken penis?
Pathognomonic sign of Hematoma penis/broken penis
Prognosis?
Tunica albuginea is ruptured
Swelling just cranial to scrotum and proximal to sigmoid flexure
Poor to guarded prognosis
Preputial Prolapse
Causes?
What prolapses?
Tx?
Complications?
Causes
- Poor sheath conformation, tick bites, abscess
Lamina interna prolapses thru preputial opening
Tx
- conservative or surgical
Complications
- stenosis formation and phimosis
What is Balanoposthitis? Cause?
Inflammation of the glans and prepuce
Usually caused by bovine herpes virus
