VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

INDIVIDUAL MOTILITY

• Motility is the most common and extensively used tool for estimating the semen quality.
• The movement of individual sperm is taken into consideration while estimating the motility.

All the fertile sperms are motile. But all the motile sperms are not fertile.

• To assess the individual motility diluted semen (diluted with physiological saline or 3% sodium citrate or Tris buffer or Tris-egg yolk extender) is kept on a warm slide and covered with cover slip.
• The slide is kept on the stage warmer of the phase contrast microscope and examined under high power. The various types of motility observed may be
  • Progressive movement - sperms with very rapid straight forward direction

  Click the link below to view video:

  • Initial motilty 10-20%,
  • Initial motilty 30-40%,
  • Initial motilty 60-70%,
  • Initial motilty 70-80%
  • Initial motilty 80%
• Circular movement - sperms with movement in circular path (Click here to view video)
• Reverse movement - sperms moving in reverse manner
• Oscillatory movement - sperms with jerky movement (Click here to view video)
• The progressively motile sperms are only taken into account, while estimating the initial motility.
• The progressive sperms will cover a distance of 100-120 µ in a second.
• Based on progressive motility, the semen samples are graded as follows.

S.No.	Progressive motility	Grade
1	90-100%	Excellent
2	70-80%	Good
3	50-60%	Fair
4	30-40%	Poor
5	0-20%	Very poor

The semen collected after long period of time will have more dead sperms.

• The sperm with circular motility indicates cold shock to the sperms.
• The heat/thermal shock also affects the sperm motility.
• A good semen sample should have an initial motility of 70%.

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