Veterinary Andrology and Reproductive Techniques

METHODS OF SEMEN COLLECTION IN STALLION

Various methods available for semen collection are

• Vaginal method
• Collection of tail end sample
• Condom or Breeder's bag method
• Artificial vagina method

Vaginal method

• Described by Frank
• Semen is collected either from vagina or uterus after natural service
• The mare should be healthy, free from genital diseases and it should not be in foal heat
• The stallion is allowed to mount, a rubber tube of 2 to 21/2 inch and 3/16 inch diameter is passed in to vagina and suction by mouth or syringe the semen is collected in a sterile glass bottle

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Collection of tail end sample

• After copulation in a stallion to a mare the last portion dripping from glans penis, urethra of male and vulva is collected in a glass tube
• This last portion or dismount portion will be and 10-30 ml and has lower concentration.
• This portion is usually contaminated with dirt.

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Condom or breeder’s bag method

Used in stallion’s by Mac Leod of Mc Gee.

• Breeder’s bag is a heavy rubber material. It has to be washed, rinsed with distilled water finally with normal saline. For reuse it should be sterilized properly.
• The stallion’s penis should be washed smegma or dirt removed and dried.
• The bag is applied over the erect penis, squeeze out the air and applied rubber bands.
• The stallion is allowed to mount, the ejaculate is collected in a pre warmed sterile tube. bottle and kept in a water bath of 35^o c for further processing.

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Artificial vagina method

• This method is better than other methods of semen collection due to more satisfactory results and less contamination.
• There are different types of AV like Missoueri model, Mississipppi model and Nishikawa model, Colorado model, Hannover model, Krakow – Polish etc.

(Click on the image to enlarge)

Preparation of AV

• Most stallions want a temperature of 45-48^o C (depends on stallion's preference).
• Adjust the pressure to stallion's preference. This keeps a lot of water in the AV and helps prevent cooling.
• Use about a tablespoon of non-spermicidal lube when you are adjusting the pressure.
• Only lubricate abut the first third of the AV. Lubricate just before collection to avoid drying out the lube and to check for foreign objects (thermometers) in the AV.

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Semen Collection

• It is best to collect a stallion when he is at his Daily Sperm Output (DSO).
  • The DSO estimates the number of cells the testicular parenchyma can produce daily.
  • This is when all the cells he is ejaculating equals the cells he is producing every day.
  • It may take 7-10 days in some cases to get to the DSO.
  • Normally the sperm output will stabilize at the daily sperm output.
  • The mean of last 3 daily collections is DSO.
  • You can estimate the DSO by taking 27.5% of second ejaculate (taken 1 hr apart). From testicular measurements:
  • DSO=-3.36 X 109 + (0.066 X 109)(SW in mm)
  • DSO=(0.024)(TV)-0.76 . (TV=(4/3)(heigth X width X length/2).
• For a stallion that has not trained to a dummy, an estrous mare is needed.
• Select a mare that is calm and does not like to kick.
• If a mare in heat is not available , an anestrus mare given 1-2 mg estradiol cypionate (ECP) will show signs of heat can be used.
• An ovariectomized mare given 2 mg ECP 2-3 days in advance is also ideal
• A dummy or phantom is ideal if the stallion is trained for it. Dummies do not move or kick.
• The phantom may also be used for semen collecion in stallion.
• Wrap the mare's tail and tie it off to the side.
• Make sure the restraint is adequate for both mare and stallion.
• Prepare the stallion
• Tease the stallion to erection.
• Wash the penis with warm water only
• All the handlers should be on left side and everyone is advised to pull to the left if there is a problem.
• The entire collection is a collective effort by everyone involved in getting a semen sample and keeping everyone safe.
• Approach the mare at an angle and allow the stallion to mount the mare.
• Let the stallion thrust and guide or allow the stallion to insert his penis into the AV.
• Gently touch the ventral penis and feel the urethra for the ejaculatory pulses. Others can watch for the flagging of the tail that indicates ejaculation.
• After the sample is collected, keep open of the AV upright to avoid spilling the semen out.
• Immediately drain the water out to prevent the continued exposure of the sperm cells to hot water.
• The water jacket also forms a 'dam' that will prevent the semen from draining into the collection bottle.
• Protect the semen from light and cold shock and then begin to analyze it as soon as possible.
• The stallion will take 20-30 seconds for ejaculation

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