Evaluating Semen Flashcards
How can a semen sample be obtained for evaluation?
- Artificial Vagina (AV)
- stallion
- trained bull
- Manual stimulation into receptable
- Dog
- Boar
- Electroejaculation
- Bull
- Billy / Ram
- Wildlife (anesthetized)
What is an artificial Vagina?
- Interior compartment is filled with warm water (110F / 44C)
- Provides temperature stimulation and pressure stimulation
What is the minimum recommended motility for semen?
How is sperm viability tested?
- Sperm must be viable to fertilize an oocyte
- Criteria to define viable sperm are not clear
- Viability stains rely on permeable plasma membrane to define a non-viable sperm
- Measures only a single aspect of viability
- Only modest correlations have been reported between this type of viability measurement and fertility
what stains can be used for viability testing?
- Eosin
- Propidium iodide
What initiates abnormal sperm morphology
insult that causes ‘stress’ results in specific abnormalities to germ cells in specific phase of development/maturation
What are the inherited sperm abnormalities?
- Knobbed defect
- Dag defect
- Tail Stump defect
- Azoospermia / Oligospermia
- Decapitated defect
- Rolled head / Nuclear crest / Giant head syndrome
How are sperm abnormalities classified?
- Based on origin (testicular / extra-testicular)
- Based on Significance (major / minor)
- Based on Functional contribution to Infertility
When using the Origin Classification System for Sperm morphology what are the different types of abnormalities?
-
Primary abnormalities - believed to arise during spermiogenesis in the seminiferous tubules due to pathological processes in the seminiferous epithelium
- Abnormal heads, abnormal midpieces, proximal cytoplasmic droplets
-
secondary abnormalities - believed to arise after the sperm cells leave the testis such as abnormal epididymal function
- bent tails, coiled tails
When using the Significance Classification System for Sperm morphology what are the different types of abnormalities?
- Major - those that have bee correlated to impaired fertility
- Minor - those that seem to be of minor importance
When using the Functional Contribution Classification System for Sperm morphology what are the different types of abnormalities?
-
Compensable abnormalities - those defects that cause an affected sperm cell to fail to reach and fertilize the ovum
- increasing the dose of sperm for AI will result in more total normal sperm and improved fertility
-
Un-compensable abnormalities - those defects that don’t prevent the cell from reaching and fertilizing the ovum, but that prevent normal development of the embryo
- Increasing dose of sperm for AI will result in the same % of abnormal sperm and the same fertility
Is this sperm abnormal? if so name the abnormality and classification.
- Distal Midpiece Reflex
- Minor - secondary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Coiled Tail
- Minor - secondary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Detached Head
- Minor - secondary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Not abnormal
- Distal Droplet
- Minor - secondary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Elongated Head
- Major - Primary Abnormality
what is
- Misshapen Head
- Major - Primary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Proximal Droplet
- Major - Primary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Pyriform Head and Bent Midpiece
- Major - Primary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
- Reversed Tail
- Minor - Secondary Abnormality
Is these sperm abnormal? if so name the abnormality and classification.
- Misshaped head
- loose tail with droplet in loop
- loose head
Is this sperm abnormal? if so name the abnormality and classification.
- Mid-piece defect
- Major - Primary Abnormality
Is this sperm abnormal? if so name the abnormality and classification.
normal sperm
What is this cell that may be seen when evaluating sperm?
- Not sperm ⇢ Medusa cell
- not supposed to be in the ejaculate
- >1 should NOT happen - bad sample
What is this cell that may be seen when evaluating sperm?
- round cell - cant tell until diff-quicked
- could be:
- germ cells
- epithelial cells
- WBC
- etc
What are the limitations of a Breeding Soundness Exam?
- Only reflects the breeding soundness on the day tested
- The sperm cells seen today were begun weeks ago
- Does not predict ability to cause conception in the future
- Better at identifying subfertile males than highly fertile males
- Many factors affecting fertility are not measured
What are the strengths of a Breeding Soundness Exam?
- Guarantees that known sub-fertile males are not used for breeding
- Removes sub-fertile males from the genetics of herd and breed
- Over time - heard and breed fertility is increased
What additional fertility tests are there for males?
- Thermography
- Ultrasound
- Computer Aided Sperm Analysis (CASA)
What is Thermography?
- Thermoregulation of tests of major domestic species is essential
- If scrotal surface temperature is high and/or displays little decrease as one moves from top to bottom of scrotum
- more abnormal sperm
- fewer pregnancies
What does ultrasound evaluate in a male breeding soundness exam?
evaluate/detect fibrosis, soft areas, spermatoceles
What is Computer Aided Sperm Analysis (CASA)
- Software programs that utilize video capture form a microscope video recorder
- Usually phase-contrast or darkfield scope
- More repeatable than subjective methods
- Motility characteristics can be altered by:
- dilution
- image settings
- semen viscosity and ionic composition
- temperature extremes
- Percentage live sperm not highly correlated to fertility
How should frozen semen be evaluated
- Much slower motility
- want >50% linear motility
- Evaluate at thaw and 2 hours post-thaw
- If AI uses few sperm cells and many are damaged how do we get any females pregnant
- deposit semen in uterus (beyond cervix) rather than vagina
