Semen Collection and Evaluation Flashcards
when do we do fertility evaluation?
PREPURCHASE
PREBREEDING
QUESTIONABLE FERTILITY
Routinely in management of valuable stallions and bulls
where and how do we collect semen?
GOOD FACILITY – safety
* GOOD EQUIPMENT *TRAINED PERSONNEL
* METHODS:
artificial vagina (AV) – stallions, bulls, small ruminants, camelids, rabbits, toms
electro-ejaculator – bulls, small ruminants, toms & zoo animals
manual – dogs, boars, poultry
- Factors Affecting Semen Quality:
Health of the animal
Season of the year
Testicular size
Frequency of collection
Intensity of teasing
Method of collection
Method of handling
Environmental temp
Semen Handling principles - after collection
- Pre-warm all slides, tubes etc.
- Warm microscope stage
- Keep semen warm
- Evaluate quickly
- Avoid contamination with lube, soap, dirt etc.
- All-plastic syringes
How do we “get the goods”?
- Species dependent
- Bull,Buck,Ram– Electroejaculator or trained to artificial vagina (AV)
- Stallion – AV (NO EEJ)
- Boar and Dog– manually into an AV
- Best to have a female in estrus present
- Stallion – AV (NO EEJ)
- Boar and Dog– manually into an AV (exception bulls for EEJ)
SEMEN EVALUATION metrics
- COLOUR
- VOLUME
- pH
- MOTILITY
- CONCENTRATION
- MORPHOLOGY
- CYTOLOGY
- SEMEN CULTURE
- Advanced tests – eg. CASA, Fluorescent stains – acrosome, membrane integrity, DNA
*Oocyte penetration assay
how do we evaluate semen colour? what factors affect this
CREAMY, MILKY, SKIM MILK, WATERY
ABNORMAL: Yellow (Pus, Urine) Red/Brown (Pus, Blood)
Factors affecting:
- Contamination
- Frequency and method of collection (determines concentration in sample)
if semen has a red colour, what does this point to?
- Blood–red-brown or red
Stallions:
* Urethral lacerations
* Urolithiasis
* Penile lesions
– Trauma
– Coital exanthema
– Tumours
Dogs: prostatitis, penile lesions
what creates variation in semen volume for collection?
- Varies between species
– Eg. 2-4 mls for bull, 60-100 mls for stallion - Method of collection
AV vs EE
Mixing fractions - Frequency of collection
- Teasing intensity – stallion
*Season – seasonal breeders
how do we measure semen motility?
- Gross Motility – place a drop on a slide - - waves and eddies – only in species with highly concentrated sperm (bull, ram, buck)
Individual Motility – with coverslip:
* Total Motility - % of cells that are moving
* Progressive Motility - % of cells moving forward in a progressive manner
- Velocity
how do we score gross motility for semen? What species?
- Swirling, Waves, Eddies seen under low power without a coverslip
Bull, Ram, Buck
Good gross motility is a factor of high concentration, a large percentage of progressively motile cells, and high velocity of movement
individual sperm motility is used as a metric for what species? what are the subcategories?
Stallion, dog, boar, bull, ram, buck
- Total Motility - % of all cells that are moving in any direction
- Progressive Motility - % of cells moving forward in a progressive manner
- Factors Affecting sperm motility:
Morphology
Temperature – cold/heat shock
- use prewarmed, clean slide, warm stage
Time between collection & evaluation
Detergents, lubricants, latex, water
Contamination with dirt, epithelial cells
what does sperm concentration allow us to calculate?
- Allows calculation of total number of sperm in ejaculate - expected range or not
> Calculation of breeding doses
methods of determining sperm concentration?
- Hemocytometer
- Densimeter
- Spectrophotometer (Spermacue)
- Nucleocounter (also does membrane integrity)
- CASA
