Artificial Reproductive Technologies I – Insemination Flashcards
Why is AI used?
To allow greater access to superior genetics, and reduce mating costs & risks
What are the advantages of using transported semen in AI?
Reduces likelihood for transmission of diseases, access to superior males, allows scrutiny of sperm quality (same for fresh)
What is one of the major disadvantages of using transported semen in AI?
Fertility of preserved sperm is generally reduced
What is the preferred method of semen collection in bulls and stallions?
Artificial vagina with teaser or dummy female
How is the concentration of sperm usually measured?
By placing sperm into a haemocytometer counting chamber
What is sperm motility dependent on?
Temperature
What is the subjective assessment scoring system used?
0 (non-motile) -> 5 (vigorous forward progression)
What is the vital stain used to assess sperm viability and what does it show?
Eosin – sperm with damaged membranes appear pink (as opposed to white)
What are the categories of sperm abnormalities?
Primary (deficit of spermatogenesis), secondary (epididymis), tertiary (post-ejaculation)
What fertilisation assays can be used to assess if sperm can fertilise?
Zona binding test & oocyte penetration test
How can sperm be sexed?
Based on separation of sperm based on their DNA content, X chromosome has 3-4% more DNA than Y chromosome
In which species does sperm freeze well?
Bull & ram
What method of insemination provides the highest lambing rate in ewes?
Uterine insemination of non-frozen semen (70%)
In which species does sperm freeze poorly?
Boar, stallion & dog
What are the main methods of semen preservation?
Fresh-extended, diluted/cooled, diluted/frozen then thawed
