AI techonologies

Question 1

Define AI

Answer 1

Placing semen into the female reproductive tract

Question 2

List examples of why AI is used

Answer 2

• Allow superior genetics
• Reduce mating costs
• Control reproductive diseases
• Part of embryo transfer regimes

Question 3

Give examples of semen collection techniques

Answer 3

• Artificial vagina
• Teaser and manual manipulation of penis
• Electro ejaculation

Question 4

How is total sperm count calculated?

Answer 4

The volume x semen concentration

Question 5

Explain how to perform a sperm count with a haematocytometer

Answer 5

• Dilute sample with either distilled water or a fixative
• Count the middle square: by counting the 4 corner squares and the central one
• The big centre is made up of 5 x 5 so times number of sperm counted by 5
• Central square volume= 0.1mm^3 (10^-4)
• sperm count= number of sperm in central square x 10^4 = this gives you number of sperm per ml
• Must multiple answer by dilution factor to give you the original concentration

Question 6

What happens to dead sperm cells when stained with eosin?

Answer 6

They take up the stain and go pink due to the damaged membranes

Question 7

Explain what is meant by primary, secondary and tertiary sperm abnormalities.

Answer 7

Primary= defect of spermatogenesis
Secondary= epididymis 
Tertiary= post-ejaculation

Question 8

What are the methods of sperm preservation and how long do they last?

Answer 8

• Fresh extended (room temp)= up to 8 hours
• Diluted/ cooled (5 degrees)= up to 4 days
• Diluted/ frozen (-196 degrees)= indefinite

Question 9

How do you preserve fresh/ chilled stallion semen?

Answer 9

• Collect sample
• Filter to remove gel
• Evaluate sample
• Dilute with extender solution
• Ship in temp controlled device
• Re evaluate sample
• Inseminate

Question 10

How do you freeze-thaw bull semen?

Answer 10

• Collect sample
• Evaluate sample
• Dilute in freezing buffer
• Slow cool to 5 degrees
• Load into straws
• Freeze at standard freezing rate in liquid nitrogen vapour
• Plunge into liquid nitrogen
• It is stored in liquid nitrogen
• Thawed rapidly by plunging in water bath

Question 11

How is semen sexed?

Answer 11

Based on their DNA content: X chromosomes have more DNA than Y chromosomes. The sperm is labelled with a DNA fluorescent dye and sorted by flow cytometry