Lecture 12: Bull Breeding Soundness Examination

- sterile

- fertile

- subfertile (get less preg, 1/5 bulls)

What knowledge do we get out of a breeding soundness exam in bulls?

- fertility is the most economically important factor for the success of a cow-calf enterprice

Why do we care if a bull is fertile or not?

- 30-60 day before breeding season

- every bull should be done every year

How often do you do BSE?

- thorough eval of bulls history

- general PE

- examination of testes and measurement of scrotal circumference

- detailed exam of the genital tract via rectal palpation

- collection and analysis of semen (motility and morphology)

What are the 5 components of a BSE in bulls?

- How long has owner had the bull?

- Vaccination and deworming

- Previous injuries or illness --> FEVERS

- Breeding history

- Record the following (Signalment, Permanent ID, and BCS)

When getting a history on the BSE, what should you talk about?

- check confirmation --> moves with ease, can smell (detect estrus) can see, free of heritable traits

- check his age via teeth

- palpate sheath for hematomas, scars, infection/abscess

- methodical examination of external genitalia

What do you do on the PE exam of a BSE, to make sure the bull is physically sound?

false

- posty legs and long lateral claws

True or false

this bull has good conformation and is good to be a breeder

- nodules

- fluid

What do you palpate the pampiniform plexus and testicular cords for?

- same size and shape

- firm (flexed forearm)

- not hot

- mobile within the scrotum

What should normal bull testicle be like?

- same shape, size and consistency

- no pain or hard spots (sperm granulomas)

What should the normal epididymis be like?

- pendulous

- no skin lesions

What should normal bull scrotum be like?

- use measuring tape at the widest part of the testicles

- size has correlation with daily sperm output and age of his heifers at puberty

Scrotal circumferance

- allows eval of internal genital structures

- need to remove feces from rectum first

- aids in semen collection by pre-stim

What is the rectal exam part of the BSE?

6. ampula (thick walled and tubular)

7. seminal vesicle (lobulated, paired, symmetrical, freely moving)

8. prostate (ring on finger)

9. urethralis muscle (broomstick on pelvis floor + contracts)

What are the palpable structures of the trans-rectal exam?

- 6, 7, 8, 9

- a broomstick on the floor of the pelvis

- 3-4 cm, muscular contractions while palpating

What does the urethralis muscle feel like on transrectal exam?

- a ring on a giants finger

What does the prostate feel like on transrectal exam?

- located craniolateral to the prostate

- is lobulated, paired, symmetrical, freely moving

- should be non-painful

What are the normal seminal vesicles like on a transrectal exam?

- thick walled and tubular

- terminal dilations of the ductus deferens

- lie along midline bt seminal vesicles

What does the ampulla like on transrectal exam?

- located just cranial and ventrolateral to pelvic brim

- slits in abdominal oblique muscles

- greater than 3 fingers may be predisposed to herniation

What are the inguinal rings like on transrectal exam?

- electroejaculation = most common and quickest

- manual massage of prostate = young bulls or refractory to EE

- AV collection = almost exclusively at stud operations

What are the methods of semen collection?

- prepuce and external sheath

- palpate penis through sheath --> freely moveable and look for abnormalities

How do you examine the external genitalia?

- put semus with a small amount of warm saline + cover slip at 400x

- can see WBC and spheroids

Semen evaluation: progressive motility

- how to make the slide and what objective

- what can you see

- 30%

What is the minimum acceptable amount of normal progressive motility allowed from bull semen?

- semen stained with eosin-nigrosin stain at 1000x oil, count 100 cells

Classified as:

- normal

- head abnormalities

- midpiece abnormalities

- tail abnormalities

Semen evaluation: morphology new classification

70%

-

What is the minimum acceptable amount of normal morphology allowed for bull semen?

- warm and clean slide

- fresh E-N stain

- drop of stain on first slide then drop of semen start near top of slide

- "waste" slides: make 2-3

How do you prepare a bull semen slide?

- diff-quik

if vesiculitis is suspected on palpation or suspicious cells on the motility slide, then stain a semen sample with _______ which allows staining of cellular materials and determination of cell type

- be able to recognize a normal vs abnormal spermatozoon

- realize that there are individuals that have good motility, but are infertile due to poor morphology

- realize that some defects are more serious than others as well as some that are hereditary

what do we know about spermatozoa morphology?

- new normal morphology

- abaxial tail implantation

What is this sperm morphology?

- new normal morphology

- distal cytoplasmic droplet

What is this sperm morphology?

grossly normal testicles

- semen of normal density

- progressive motility with goof post-that viability

Some bulls produce abaxial tail tails, what are their reproductive tracts like?

- cytoplasmic droplets just proximal to the annulus

- occurs as cells shred and mixed with seminal plasma

- issues does not appear to originate in the testis

What is a distal cytoplasmic droplet?

- heat

- stress

- genetics

- toxins

- nutrition

- infectious diseases

What are reasons for increased abnormalities in sperm that you should think of?

- increase cell metabolism --> hypoxemia

- issues with thermoregulation (fat, fluid, scars, ect)

How does heat cause sperm morphologic abnormalities?

- illness, pain, hunger, inclement weather = stress

- suppression of LH and FSH

- 3-4 days duration to cause an effect

How does stress cause sperm morphologic abnormalities?

- 3 weeks

Percent of normal sperm is lowest ______ post heat/stress

- 6 weeks

Return to pre-treatment levels by _____ post insult of heat or stress.

- Snapshot in time

- No reliable chute side assessment of libido or mating ability

- does NOT guarantee that a bull is highly fertile

- Does NOT rank bulls with respect to fertility

- Does NOT ensure bulls are free of infectious agents in their semen

What are the limitations of BSE?

- not part of normal BSE

- if the bull has a history of infertility and or failed breathing can do this

- looks at penile deviations, labido, ability to make intromission

What is bovine test mating?

- Progressive Motility ≥30%

- Normal Morphology ≥70%

- Appropriate scrotal circumference based on age

- No physical defects noted

What does a BSE final classification satisfactory mean?

- Does not meet or exceed any one of the above requirements

What does BSE final classification of unsatisfactory mean?

- Can re-test in 60 days

What does a BSE final classification deferred mean?