Bull Breeding Soundness Exam

Lecture 12

When are BSEs performed?

30-60 days prior to breeding season every year

What are the components of a BSE?

thorough evaluation of the bull’s history

general physical exam

examination of the testes and measurement of scrotal circumference

detailed examination of the genital tract via rectal palpation

collection and analysis of representative semen sample to evaluate motility and morphology

What are the four parts of a BSE that a bull must pass to be a satisfactory potential breeder?

physical examination (no physical defects can be noted)

minimum scrotal cricumference based on age

minimum progressive motility (30%)

minimum morphologically normal cells (70%)

What structures should be included in methodical palpation of the external genitalia during a BSE?

pampiniform plexus and testicular cords

testicles

epididymis

scrotum

Why do we care about scrotal circumference on BSE?

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

What structures should be palpable on trans-rectal examination during BSE?

internal genital structures —> ampulla, seminal vescile, prostate, urethralis muscle, inguinal rings

What internal genital structure feels like a broomstick on the floor of the pelivs, is roughly 3-4cm, and you can feel its muscular contractions while palpating?

urethralis muscle

What internal genital structure feels like a ring on a giant’s finger while palpating?

prostate

What internal genital structure is located craniolateral to the prostate, is lobulated, and is paired, symmetrical, and freely movable?

seminal vesicles (vesicular glands)

What interal genital structure is a thick walled tubular structure 1.5cm in diameter that lies longs the midline between the seminal vesicles with terminal dilations of ductus deferens?

ampulla

What internal genital structure is located just cranial and ventrolateral to the pelvic brim and sits in the abdominal oblique muscles?

inguinal rings

Inguinal rings greater than what size may be predisposed to herniation?

3 fingers

What are 3 methods for semen collection?

electro-ejaculation

manual massage

AV collection

Describe how to evalaute semen progessive motility.

small amount of semen diluted with warm physiologic saline

cover slip on 400x

minimum acceptable is 30%

Describe how to evalaute semen morphology.

semen stained with eosin-nigrosin stain

oil 1000x

count 100 cells

classify as normal, head abnormalities, midpiece abnormalities, tail abnormalities

minimum acceptable is 70% normal (<20% head or mid-piece abnormalities)

Primary classification for sperm morphology indicates what?

that the defect originates in the testis during spermatogenesis

“production problem”

usually involves head and mid-piece

Secondary classification for sperm morphology indicates what?

a defect that originates in the epididymis

“transit defect”

Major classification indicates what for sperm morphology?

negative effect on fertility

Minor classification indicates what for sperm morphology?

not associated with negative effect on fertility

Compensable classification indicates what for sperm morphology?

create zona block but an increase in sperm dosages overcome the defect

Non-compensable classification indicates what for sperm morphology?

abnormal sperm is capable of initiating the zona reaction but incompetent to fertilize

Describe how to prepare a slide for semen morphology evaluation.

warm, clean slide

fresh E-N stain

drop of stain on slide first, then semen drop —> make sure to place near top of slide

use another slide to create smear —> let dry then stain

waste slides can make 2-3 more slides for evaluation

What should you do if vesiculitis is suspected based on palpation or suspicious cells on the motility slide?

stain a semen sample with Diff-Quik which allows staining of the cellular material and determination of the cell type

What can cause increases in abnormal sperm morpholohy?

genetics

toxins

nutrition

infectious diseases

heat

stress

Why might be perform a test mating in a BSE (not usually in a normal BSE)?

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

also reveals penile deviations, evaluation of libido, and ability to make intromission

If a bull is deferred after his initial BSE, when can he be re-tested?

60 days

List limitations of a BSE.

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

Describe normal testicles on palpation.

should be same size and shape

firm like a flexed forearm

normal temperature

mobile within the scrotum

Describe normal scrotum on palpation.

pendulous with no skin lesions