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68 Cards in this Set

  • Front
  • Back
Methods of obtaining semen samples
-artificial vagina
-manual stimulation into receptacle
-electroejaculation
Artificial vagina
-used for what animals
-stallion
-trained bull
Artificial vagina
-interior compartment
-filled with warm water because the stallion is a temperature sensitive ejaculator
Artificial vagina
-provides what
-temperature stimulation
-pressure stimulation
Manual stimulation into a receptacle
-animals
-dog
-boar
Manual stimulation into a receptacle is for what kind of ejaculator
-pressure sensitive
Electroejaculation
-animals
-bull
-billy/ram (sedated)
-wildlife 9anesthetized)
Things that corrupt collection of a representative semen sample
-first part of the sperm rich fraction in the epididymis with sexual rest may be abnormal
-fecal contamination, urine, water, soap, and blood can adversely effect motility and make it difficult to do a good sperm morphological exam
-high and low environmental temperatures can affect sperm motiility
Are the volume of ejaculate, sperm density, and gross characteristics good predictors of fertility?
-NO
Methods of assessing sperm motility
-gross motility
-individual motility
Semen motility
-minimum recommended motility
-30% or fair
Sperm motility
-very good rating (gross, individual)
-gross: rapid swirling

-individual: >70%
Sperm motility
-good rating (gross, individual)
-gross: slower swirling

-individual: 50-69%
Sperm motility
-fair rating (gross, individual)
-gross: generalized oscillation

-individual: 30-49%
Sperm motility
-Poor rating (gross, individual)
-gross: sporadic ascillation

-individual: <30%
Does sporadic oscillating semen mean there is a problem?
-Not necessarily
-sample can be very dilute and would need to be re-evaluated
Why should latex gloves not be worn when handling semen?
-latex is spermicidal
Warming plate should be used for:
-slides
-stains
-coverslips
-semen

*keep warm at all times and prevent cold shock
Examination of gross motility
-procedure
-place drop of semen on a warmed slide and observe under 100x (low) magnification
Examination of individual motility
-procedure
-assess under bright-field or phase-contrast microscopy at 400x
Individual motility examples
-dilution
-sodium citrate
or
-skim milk based semen extender
or
-physiological sterile saline (if exam done promptly)
Differential counts of normal and abnormal sperm are generally assessed by:
-phase-contrast microscopy using samples fixed in formalin-buffered-saline or PBS-gulteraldehyde
-bright field microscopy of stained smears
Morphological exam
-magnification
-1000x
Evaluation of semen morphology
-stains
-nigrosin-eosin
-williams stain
-modified giemsa
-DifQuik
-India ink
Morphologic evaluation
-how to stain
-1 drop semen mixed with 1 drop nigrosin-eosin and the mixture is spread over the surface of a glass slide and allowed to dry
-vary smear thickness
Morphological evaluation
-requirement for bull to pass BSE
-al least 100 random sperm need to be observed and at least 70% of observed cells need to be normal
If a particular semen sample has a high number of abnormalities, what may be necessary?
-counting 500 or more sperm
Sperm
-viability stain
-Eosin or Propidium iodide
-relies on a permeable plasma membrane to define a non-viable sperm
Why is a viability stain not very well correlated with fertility?
-we have no idea how viable the unstained sperm are, we just know that they are viable
Rather than different insults causing different morphological abnormalities, ______________
a number of different insults cause stress which results in specific abnormalities to germ cells in specific phases of development/maturation
Inherited sperm abnormalities
-why rarely seen
-cause infertility
Inherited sperm abnormalities
-effects
-knobbed defect
-dag defect
-tail stump defect
-azoospermia/oligospermia
-decapitated defect
-rolling head/nuclear crest/giant head syndrome
Sperm cell morphological classification systems
-based on origin (testicular, extra-testicular)
-based on significance (major/minor)
-based on functional contribution to fertility (compensable/uncompensable)
Sperm Morphology based on origin
Primary abnormalities
-arise during spermatogenesis in seminiferous tubules due to pathological processes in the seminiferous epithelium
-abnormal head, abnormal midpiece, proximal cytoplasmic droplet, etc.

Seconday abnormalities:
-arise after sperm cells had left testis such as abnormal epididymal function
-bent tails, coiled tails, etc.
Sperm morphology based on significance
Major abnormailites
-correlated to impaired fertility

Minor abnormalities
-minor importance

*difficult to figure out
Sperm morphology based on functional contribution to infertility
Compensable abnormalities
-defects that cause an affected sperm cell to fail to reach and fertilize the ovum
-sperm can induce zona reaction
-increasing the dose of sperm (A.I.) will result in more total normal sperm and improved fertility
-ex) tail problem that precludes forward motility

Uncompensable abnormalities
-defects that don't prevent a sperm from reaching the ovum but prevent normal development of the embryo
-sperm can't induce zona reaction
-increasing sperm dose A.I. will result in same percentage of abnormal sperm and hence same fertility
What is it?
-describe
What is it?
-describe
-Fertility Dose-Response Curve

-Fertility plateaus at 5-10 million sperm cells
-Bull C has compensable sperm abnormalities
-Bull D has non-compensable traits
Describe abnormality
-type of abnormality
Describe abnormality
-type of abnormality
Strongly folded midpiece
-Major/Primary abnormality
Describe abnormality
-type of abnormailty
Describe abnormality
-type of abnormailty
Coiled tail
-Minor/Secondary abnormality
Describe abnormality
-Type of abnormality
Describe abnormality
-Type of abnormality
Detached head
-Minor/Secondary abnormality

*not uncommon to find in a normal semen sample
Describe abnormality
-type of abnormality
Describe abnormality
-type of abnormality
Distal droplet
-Minor/Secondary abnormality

*not abnormal
Describe abnormality
-type of abnormality
Describe abnormality
-type of abnormality
Elongated head
-Major/Primary abnormality
Describe abnormality
-type of abnormality
Describe abnormality
-type of abnormality
Misshapen head
-Major/Primary abnormality
Describe abnormality
-Type of abnormality
Describe abnormality
-Type of abnormality
Proximal droplet
-Major/Primary abnormality
Describe abnormality
-type of abnormality
Describe abnormality
-type of abnormality
Pyriform head and bend midpiece
-Major/Primary abnormality
Describe abnormality
-Type of abnormality
Describe abnormality
-Type of abnormality
Reversed tail
-Minor/secondary abnormality

*probably human error from cold shock if a C-shaped bend is present in the tail
Describe abnormality
-Type of abnormality
Describe abnormality
-Type of abnormality
Medusa cell
-unknown
Presence of spermatogenic epithelial cells (spheroids) in the semen suggests what?
-poor health of the seminiferous tubules
Breeding soundness exam
-limitations
-only reflects breeding soundness on the day tested
-sperm cells seen today were begun weeks ago
-does not predict ability to cause conception in the future
-better for identifying subfertile males than highly fertile females
Breeding soundness exam
- strengths
-guarantees that sub-fertile males are not used for breeding
-removes subfertile males from the genetics of the herd and breed
-over time herd and breed fertility are increased
Breeding soundness exam
-interpretation
-good at IDing poor performing males
-bell shaped curve does not allow us to predict how males that pass BSE will perform
Ultrasound
-use
-evaluate/detect fibrosis
-soft areas
-spermatoceles
Thermography
-use
-check thermoregulation of testes
-if scrotal surface temp is high or displays little decrease as one moves from the top to the bottom of the scrotum there are: more abnormal sperm, fewer pregnancies
Computer Aided Sperm Analysis (CASA)
-equipment
-software that utilize video capture from microscope video recorded
-phase contrast or darkfield microscope
Computer Aided Sperm analysis
-motility can be altered by
-dilution of semen
-image settings
-semen viscosity and ionic composition
-temp extremes
Evaluation of frozen semen
-preferred values
> 50% linear motility (slower motility)
Evaluation of frozen sperm
-when to evaluate
-thaw
-2 hours post thaw
If AI uses fewer sperm cells and many are damages, how do we get cows/mares/b!tches pregnant?
-deposit semen in uterus rather than vagina
Evaluation of sperm quality has arisen because:
-our desire to predict fertility

*goal has not been achieved
Role for in vitro evaluation of sperm quality
-predicts male will be less fertile than average males
-can predict that a given sample has a high probability of providing similar to that he has achieved in the past (if males with known fertility had semen characterized in the past)
What can't be done with in vitro evaluation of sperm quality?
-can't take a male with unknown fertility and predict that his fertility will be greater than the mean for fertile males
CASA
-measured characteristics
-Percent motility
-Velocity curvilinear
-Velocity average path
-Velocity straight line
-Linearity
-Wobble
-Progression
Attributes of sperm essential for fertility
-acceptable morphology
-maturation of spermatozoa within the proximal epididymis
-maturation of membrane lipids
-maturation of membrane proteins
-activation of integral enzymes associated with fertilization
-upon exposure to the micro-environment of the oocyte
-upon exposure to the cytopplasm of the oocyte
Frozen semen
-chemical and physiological shanges that occur during freezing and thawing
-partial dehydration
-cryprotectant penetration of cells
-reorganization of membrane lipids and proteins
-exposure to high salt concentrations
-exposure to inter and intracellular ice crystals
Evaluation of frozen semen
-purpose of evaluation post-thaw
-evaluate degree of sperm damage inflicted by crypreservation feature
Diadem Crater Defect
-induced by
-pyrexia
-ethylene dibromide
-sulfasalazine
-corticosteroids
-low testosterone
-viruses
Midpiece defect
-induced by
-Gossypol
-Ethylene dibromide
-Genetics
-Respiratory disease
Gossypol
-effects on bull repro tract
-degeneration and reduction of spermatogenesis
-damage to the basement membrane of spermatogenic tubules
-increase in abnormal sperm