Bovine: Semen Eval

Question 1

When is the breeding soundness exam (BSE) performed? what 3 things does it test for?

Answer 1

performed yearly in may-june
1. physical soundness
2. semen quality and quantity
3. serving capacity

Question 2

What do we look for in terms of physical soundness during BSE?

Answer 2

observe in a holding pen or raceway
assess for lamness (walking far distances), visual deficits (can he see?), any injuries ( too sore to mount), BCS (too fat/thin)

Question 3

How can we assess physical soundness while in a headgate?

Answer 3

catch their head in a head gate and check for their ID and tattoos
leave the head free in the chute so it prevents the bull from kneeling or lying down during electroejaculation

Question 4

Why might we evaluate testicals? How do we evaluate?

Answer 4

scrotal exam to eval for gross abnormalities, size
ensure bull is well restrained and pose is between anus and hocks to prevent kicking
tags on bull hindquaters, inside of legs b4 touching scrotum
palpate for testicles, epididymides, inguinal hernia and evidence of frostbite/scars

Question 5

How does one measure and evaluate the testicle?

Answer 5

Scrotal circumference - correlates w/ testicular weight. Lger testes = more sperm = more service capacity. Also daughters w/ inc fertility so they come into puberty earlier + longevity
Measure by holding testes in bottom of scrotum with thumb and forefinger at neck (don’t squeeze down) then place tape around widest part of scrotum - tighten until junction of green/red indicator
repeat 3 times, take average. size dependant on bull age/breed

Question 6

What do we evaluate for accessory sex glands?

Answer 6

palpate accessory sex glands and inguinal rings
Done via rectal exam
exam the inguinal rings for any hernias and the accessory sex glands for seminal vesiculitis

Question 7

What do we look for during penis and prepuce evaluation?

Answer 7

prepuce - is it prolapsed, injuries, ulcers/sores
penis - corkscrews/deviations? any warts (need to be sx removed if not too pig), any persistent frenulum(a heritable condition in which the tip of the penis remains attached to the sheath and cannot be extended) (can be snipped BUT is inheritable so purebred breeders would cull these bulls from their program

Question 8

How is semen collected?

Answer 8

by rectal massage of ampulla - very labour intensive, often do not protrude penis bc it has an inaccurate volume, concentration and total sperm count

used when electroejaculator not available. bull reacted negatively to electrojac in the past

Question 9

How might we collect sperm to be frozen?

Answer 9

artificial vagina
accurate parameters - sperm conc, ejact volume and total sperm count

better collection than electroejac

Question 10

What are electroejaculators?

Answer 10

a rectal probe at least 30cm lengthx6cm diameter - larger probes for larger bulls
electrodes facing ventral
ushaped cradle for tail prevents rotation
has a rheostat which provides electrical stimulation
does have inaccurate volume, concentration and total sperm count

Question 11

How is electroejaculators used?

Answer 11

electrical stim on nerves responsible for erection and ejaculation
empty rectum of feces prior to insertion
slowly inc stim in pulsations (2s of stim, 0.5-1s of rest, slight contraction of muscles in hind limbs that inc with each pulse)
start very gentle on young bulls

Question 12

How do we collect semen with electroejaculators?

Answer 12

collect semen in sleeve as bull ejaculates
immediately eval semen for motility + estimated concentration on pre-warmed slides @ 37 degrees

Question 13

What is semen concentration? What values are poor, fair, good and very god? What needs to be done if we are freezing semen?

Answer 13

An estimate - AV method most accurate
Very Good = Cream, grainy – 750 million to 1 billion sperm/mL
* Good = 2% milk – 400 to 750 million sperm/mL
* Fair = skim milk – 250 to 400 million sperm/mL
* Poor = translucent - <250 million sperm/mL
* If freezing semen, then an absolute count with a
hemocytometer must be performed

Question 14

What is gross motility? How much semen is needed? What determines poor, fair, good and very good?

Answer 14

Mass wave motion - in terms of concentration and the % of progressively motile cells and the speed of progression
1 drop of semen on a pre-warmed
slide
* 4x magnification
* Very Good = rapid dark swirls
* Good = slower swirls
* Fair = no swirls, but individual cell
motion
* Poor = little or no individual cell motion

Question 15

What is progressive motility? What do we need? What determines poor, fair, good and very good?

Answer 15

individual motility
Add drop of diluent (saline or semen extender)
* Add coverslip
* 40x magnification
Observe individual sperm cells for progressive motility – are they going somewhere?
* Very good = >70%
* Good = 50-70%
* Fair = 30-50%
* Poor = <30%

Question 16

What is needed to look at sperm morphology?

Answer 16

Eosin-nigrosin stain
* 1 drop of EN stain at frosted edge of slide
* Add 1 drop of semen next to stain
* Mix together with a wooden
applicator stick
* Spread to edge of slide with slight
back and forth motion
* Blow/wave slide to dry
* Prevent artifact tail abnormalities
* 100x magnification

Question 17

What determines live vs dead semen?

Answer 17

dead - purple discolored, white = live
percent live - differntial count x 100

Question 18

What is the differential count of semen morphology? what are some normal morphology?

Answer 18

differential - count defects vs normal out of 100
considered normal - distal droplets and abaxial tail ( tail does not come out of head centered)
>70% normal morphology to pass BSE

Question 19

What is service capacity of BSE? For >2yrs old and <2yrs old. Variables?

Answer 19

not apart of BSE
>2yrs is 30-60 cows/breeding system,
<2yrs is 15/breeding system
variables are libido, ability to intromit, competition/intimidation from other bulls

Question 20

What happens once a BSe iscomplete?

Answer 20

1classified as
1. satisfactory
2. unsatisfactory
3. deferred
typically wait at least 60 days prior to retesting deferred bulls which is the life cycle of sperm cells

Question 21

When might trich testing be done?

Answer 21

done at the same time as BSE as trichomoniasis is sexually transmitted protozoa infection which causes abortion in cows
protozoal parasite Tritrichomonas foetus (T. foetus)
bulls carry it in their prepuce/smegma and are asymptomatic carriers which transmit to cows when they breed