Semen extender

Function

The addition of extender to semen protects the sperm cells against possible damage by toxic seminal plasma, as well as providing nutrients and cooling buffers if the semen is to be cooled. Semen extender also serves to protect sperm from bacteria by adding antibiotics to it to prevent increase of bacteria. In the case of freezing extenders, one or more penetrating cryoprotectants will be added. Typical cryoprotectants include glycerol, DMSO and dimethylformamide. Egg yolk, which has cryoprotective properties, is also a common component.

Ingredients

In the equine Kenney extender (named after its developer, Dr. Robert M. Kenney) has been used for many years, and contains a non-fat dried milk solid (NFDMS) and glucose. Dual-sugar extenders typically have similar ingredients, with an additional sugar, sucrose. Other extenders (e.g., INRA '96) may also contain milk components.

Antibiotics are almost universal in semen extenders, especially those being used for shipping or freezing semen. Ticarcillin (often used in combination with clavulanic acid under the designation Timentin), amikacin sulfate, penicillin, and gentamicin are commonly used. The latter - gentamicin - has been noted to reduce sperm motility in the equine. In human semen extenders, antibiotics are required for regulatory reasons, so their use is almost universal in clinics, even though antibiotics can be detrimental to sperm. This is because in procedures such as IVF with frozen sperm, the sperm does not need to swim up the reproductive tract on their own, and the detrimental effects of the antibiotics are not problematic. When private donors ship chilled semen outside of the formal regulatory environment, and fertilization is accomplished by allowing sperm to swim through the reproductive tract without the help of procedures such as IVF, then it is possible to achieve better results without antibiotics.

Brands

Porcine

• Androhep Plus
• Androstar Plus
• Androstar Premium
• Merck III
• BTS
• MR-A
• Beltsville Liquid (BL-1)
• Acromax
• Beltsville Thawing Solution (BTS)
• Illinois Variable Temperature (IVT)
• Kiev
• MULBERRY III
• Reading
• X-Cell
• Zorlesco
• ZORPVA
• MS Dilufert, various generations (3, 6, 9, 10)
• Preserv Xtra

Bovine

• Andromed
• Andromed CSS
• Bioxcell
• CRYOBOS
• Triladyl
• Biladyl
• Steridyl
• Biociphos
• Bovifree

Equine

• AndroMed-E
• Kenney (often marketed under a brand name - e.g. E-Z Mixin')
• VMDZ
• BotuCrio (Botupharma)
• INRA '96
• Universal dual-sugar
• Gent Extenders
• Equipro
• Spervital extenders (http://www.spervital.nl)
• EQUIDIL (EMBRYOLAB-UFSM)
• SBS semen extenders

Human

• Test Yolk Buffer (TYB) by Irvine

References

References

1. [http://www.equine-reproduction.com/articles/faqai.htm] Equine-Reproduction.com - FAQ-AI article
2. [http://www.equine-reproduction.com/articles/faqfro.htm] Equine-Reproduction.com - Frozen Semen FAQ article
3. (2 June 2010). "Increasing Semen Volume".
4. Vera-Munoz O., Amirat-Briand L., Diaz T., Vásquez L., Schmidt E., Desherces S., Anton M., Bencharif D., Tainturier D.; (2009) Effect of semen dilution to low-sperm number per dose on motility and functionality of cryopreserved bovine spermatozoa using low-density lipoproteins (LDL) extender: Comparison to Triladyl and Bioxcell; Theriogenology 71:6; 895-900
5. [http://www.ca.uky.edu/gluck/AboutHOFKenney.asp The Equine Research Hall of Fame - Robert M. Kenney]
6. Aurich C., Spergser J., (2007) Influence of [[bacteria]] and gentamicin on cooled-stored stallion spermatozoa; Theriogenology 67:5; 912-918
7. "Semen extenders used in the artificial insemination of swine. A review". Spanish Journal of Agricultural Research (2003) 1 (2):17-27.