12-Bull Breeding Soundness Exam

What percent of bulls are sub-fertile? Due to what?

20% are sub-fertile due to physical unsoundness or poor seme quality

When should you perform a BSE?

30-60 days prior to every breeding season

What are the steps of a BSE?

Thorough evaluation of the bull's history

General PE

Exam of the testes and measurement of scrotal circumference

Detailed exam of the genital tract via rectal palpation

Collection and analysis of representative semen sample

-motility and morphology

Under the bull BSE guidelines set by society for theriogenology, a bull must pass all four parts of the exam. What are these 4 parts?

Physical exam

Minimum scrotal circumference based on age

Minimum progressive motility (30%)

Minimum morphologically normal cells (70%)

What should you be checking for in your history?

How long has the owner had the bull

Vaccination and deworming status

Previous injuries or illness

-check for fever

Breeding history

Record signalment, permanent ID, BCS

What determines if a bull is physically sound to breed?

Be able to move with ease

Detect female in estrus

Mount and complete breeding (inspect eyes for pinkeye, active or scarring, and tumors)

Be free of heritable defects

What should you palpate the sheath for?

Hematomas

Scars

Abscesses

Infection

Bad bull pic

What should the normals be for the testicles, pampiniform plexus and testicular cords, epididymis, and scrotum?

What is the minimum recommended scrotal circumference be for ages 15m, 15-18m, 18-21m, 21-24m and > than 24m?

How do you palpate internal genitalia and inguinal rings?

Rectal palpation

-aids in semen collection by pre-stimulation for electroejaculation

What are some palpable structures of the male reproductive tract?

Ampulla

Seminal vesicle

Prostate

Urethralis M

What does the urethralis m feel like during palpation?

Feels like broomstick on floor of pelvis

3-4cm

Muscular contractions while palpating

What does the prostate feel like during palpation?

Feels like a ring on a giant's finger

What do the seminal vesicles feel like during palpation?

Located craniolateral to the prostate-lobulated

Paired, symmetrical, freely movable, non-painful

What does the ampulla feel like during palpation?

Thick, walled tubular ~1.5cm in diameter

Terminal dilations of ductus deferens

Lie along midline between seminal vesicles

What do the inguinal rings feel like during palpation?

Located just cranial and ventrolateral to pelvic brim

Slits in abdominal oblique muscles

Greater than 3 fingers in size, may be predisposed to herniation

What are some semen collection methods?

Electro ejaculation

Manual massage (ew)

Artificial vagina (AV) collection

What are the advantages of electro-ejaculation?

Most commonly used collection method

Quickest way to get semen from several animals in one day

What are the advantages of a manual message (ew)?

Useful in young bulls

Bulls refractory to EE

What are the advantages of AV collection?

Used almost exclusively at bull stud operations

What abnormalities should you check the penis for?

Warts

Hair ring

Persistent frenulum

Corkscrew penis

Diphallus, etc

What is the process of measuring progressive motility?

Small amount of semen diluted with warm physiologic saline

Cover slip on 400X

-appoint a percent motility number

What cells should you see on a progressive motility slide? What should you not see?

See WBCs and spheroids

Should not see round cells

What is the minimum acceptable progressive motility?

30%

What is the process of measuring semen morphology?

Semen stained with eosin-nigrosin stain

Oil 1000X

Count 100 cells

Classify:

-normal

-head abnormalities

-midpiece abnormalities

-tail abnormalities

What is the minimum acceptable morphology percent?

70% normal sperm

-

What does the primary-secondary classification scheme for sperm morphology mean?

Used prior to 2018

Primary:

-a defect that originates in the testis during spermatogenesis

-"production problem"

-usually involves head and mid-piece

Secondary:

-a defect that originates in the epididymis

-"transit defect"

What does the major-minor classification scheme for sperm morphology mean?

Based on effect on fertility

Major has negative effect on fertility

Minor not associated with negative effect on fertility

What does the compensable, non-compensable classification scheme for sperm morphology mean?

Based on ability to access the ovum

-if the abnormal sperm is capable of initiating the zona reaction but incompetent to fertilize it is non-compensable

Create zona block

Increase in sperm dosages overcome defect (compensable)

Slide preparation

How should you prepare a slide if vesiculitis is suspected?

Stain a semen sample with diff-quik which allows staining of the cellular material and determination of the cell type

What is abaxial tail implantation of sperm?

Reported as normal in other species

Retrospective study found sperm with an abaxial tail attachment fertilize ova at a normal rate-DOES NOT AFFECT FERTILITY

What do bulls with abaxial tail implantation present as?

Grossly normal testicles

Semen of normal density

Progressive motility with good post-thaw viability

What are distal cytoplasmic droplet sperm?

Cytoplasmic droplets just proximal to the annulus

Normally shed as cells are mixed with seminal plasma and motility ensues as membrane stretches (much of cellular debris on spermiogram)

Sperm aberration does not appear to originate in the testis or epididymis

Previously considered a secondary abnormality

DOES NOT AFFECT FERTILITY

What is the hypothesis of how distal cytoplasmic droplet sperm are formed?

Lack of hemolytic factor (phospholipid binding protein) found in seminal plasma

Insufficient amount of seminal plasma is released

What do dag defect sperm look like? What breed of cows are they hereditary in?

Jersey's and Herefords

What do tail stump defect sperm look like? How are they inherited?

Inherited as a recessive condition

Different sperm defect reference chart

What makes a cratered appearance on sperm?

Due to redundant membrane beneath the plasma membrane

What are some possible reasons for increases in sperm abnormalities?

Genetics

Toxins

Nutrition

Infectious diseases

Heat

Stress

How does stress affect fertility?

Suppresses LH and FSH

-decreased testosterone by leydig cells

-sertoli cells function is testosterone dependent

3-4 days of stress duration causes an effect

When is the percent of normal sperm lowest post heat/stress? When does it return to normal?

Lowest at 3 weeks

Return to normal at 6 weeks

What are the limitations of BSEs?

When would you perform a test mating? What does it reveal?

If the bull has a history of infertility and/or failure to breed

Reveals:

-penile deviations

-evaluation of libido

-ability to make intromission

How long do you have to wait to retest a BSE?

60 days