A Guide to Basic Boar Semen Evaluation, Processing, and Storage Procedures

1. A Guide to Basic Boar Semen Evaluation, Processing, and Storage Procedures

2. General • There are numerous methods available for processing semen which utilize various equipment items and techniques. Always keep in mind the two basic principles of semen collection and processing. • (1) Use hygienic techniques. • (2) Control temperature changes. • For the most part, if these principles are followed, specific techniques and equipment, which are used, become a matter of economics, ease of maintaining quality control and personal preferences.

3. Preparing Extender • Prepare extender at least 30 minutes before it is to be used. • Always use distilled water. • 1 liter pouch per 1000ml distilled water. • Stir often. • Target temperature, 102* F. • Unused extender (in an enclosed container or bag) can be stored in a refrigerator for 24 to 48 hours.

4. Function of Extender • Lengthen the viability of undiluted semen by protecting it against cold shock. • Act as a buffer against low pH. • Provide proper osmotic pressure and electrolyte balance. • Inhibit bacterial growth (added antibiotics). • Supply nutrients to the sperm (glucose). • Extend the use of the ejaculate so more females can be inseminated per ejaculate.

5. Estimate and Calculate • Weigh the collection container and subtract the tare weight. This will give you the ejaculate volume. Note: Semen is actually slightly heavier than water which weighs 1 gram per ml or cc, but use a 1 to 1 ratio, this is close enough. • Use your microscope to evaluate sperm motility and concentration. Always use a pre-warmed glass slide and cover slip. Ejaculates with a progressive motility estimate of less than 60% are generally discarded. Observe for the presence of abnormal sperm and cellular debris and "clumping".

6. Normal

7. Pear Shaped Hd

8. Detached Acrosome

9. Clumping

10. Acrosome Lifting

11. Proximal Droplet

12. Coiled Tail

13. Elongated Head

14. Distal Droplet

15. Estimate and Calculate 2 • Decide how many bottles (units) of semen that can be processed from the ejaculate. Each bottle should contain about 3 to 4 billion sperm and 80 to 100 ml fluid. The boar ejaculate may contain from a low of 10 to 15 billion up to over 100 billion sperm or enough sperm for 2 or 3 bottles up to 25 or more bottles. This number depends upon age, breed, frequency of collection, and individual boar. If you do not have a sperm counting device, you will have to follow some guidelines. Actually you will make an educated guess. Depending upon relative sperm density (opaqueness) most recommendations are to dilute the ejaculate from 1 part semen to 3 parts extender up to 1 part semen to 10 parts extender. The more opaque and chalky appearing, the higher the possible dilution rate.

16. Examples • 3 = watered down milk; 6 = milky; 10 = creamy

17. Extending Semen • Cardinal Rules • 1. Adjust extender temperature to within 1° of semen temperature. • 2. Always add the extender to the semen.

18. Extending Semen 2 • Always add extender to semen slowly. • When bottling/tubing semen, remove as much excess air as possible. • Allow semen to gradually cool to approximately 72*-75* F. • Keep away from sunlight or other U.V. light.

19. Storage & Shipping • Ideal temperature range from 54*-62* F. • Avoid temperature fluctuations. • Avoid temperature <48* and >72* F. • Gently rotate semen daily.

20. Storage & Shipping 2 • Factors that affect semen longevity. • Age of boar • Breed of boar • Frequency of collection • Type of extender used