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0307 PD: Practice good A.I. techniques

W.M. Graves Published on 06 March 2007

It is well known that daughters from artificial insemination (A.I.) sires produce more milk than those bred by natural service. Incorrect A.I. techniques can lower the overall success rate of your breeding program. At one time, most producers have learned correct techniques in semen handling and insemination procedures, but unfortunately, many have developed some bad habits. Reviewing proper procedures should help eliminate many of these mistakes.

Keep your semen tanks in a secure, clean and dry place away from corrosive chemicals. Your tank’s location should allow for easy moving for filling with liquid nitrogen. Tanks should be stored in a visible place, and the nitrogen level should be checked regularly.

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Only store about a six-month supply of semen. Make sure your investment is insured and secure. Always check the semen inventory list prior to removing semen from a tank to make sure each time that the correct canister is used.

Semen should not be lifted above the frost line in the neck of the nitrogen tank. Dangerous temperatures exist in the upper half of the neck. Exposure will lower subsequent fertility.

Store insemination equipment in a clean, stainless steel box. This box should be closed when not in use. Also, all equipment should be clean when returned to the box. Always maintain sterility of the plastic sheaths used to cover the straw gun. Remember this is not a tool box; put the drill somewhere else.

Restrain and identify the cow to be bred before thawing the semen. Be sure the cow being bred is in heat. Use the am/pm rule or breed at a designated time after Ovsynch hormone treatment.

When preparing the A.I. gun remove the plastic straw of semen from the goblet quickly with tweezers and not fingertips. This helps to keep the straws in the goblet below the frost line and avoids warming the straw too quickly.

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It is generally recommended only one straw be thawed at a time. If more than one straw is thawed, they should be agitated to prevent the possibility of freezing together during thawing. If synchronizing animals you can thaw up to three straws together if you are using them within 15 minutes. This works best if the inseminator has help loading and thawing semen.

Shake the straw after it is removed from the tank to eliminate any drops of nitrogen at the end of the cotton plug. This will eliminate the plug bursting off when it is put in the water bath. If you have a large group of animals to inseminate, it will help to have one person thawing and another breeding animals.

A one-pint, wide-mouth thermos and a dial thermometer work well for thawing straws. Semen should be thawed in 95°F water for 45 seconds. Electronic thaw devices are handy, especially DC versions that can be used in trucks. Maintain accuracy by regularly checking temperatures and calibrating your thermometer. After the straw is thawed, dry it off with a clean towel and always check the printed information on the outside of a straw to verify the bull’s identity. Record the bull next to the cow’s number. Maintain an accurate semen inventory.

Use semen within 15 minutes of thawing. Time should be watched carefully, especially when thawing multiple straws. In cold weather, warm the gun by rubbing it with your hands.

Dry the straw with a clean paper towel and place the end with the cotton plug in the gun. Cut the sealed end at a 90-degree angle about 0.25-inch from the lab seal. If the straw is not cut squarely, the plastic sheath does not seal tightly against the straw. Some semen will then backflow between the sheath and the straw, rather than going inside the cow. A 1/2cc straw contains about 10 drops of diluted semen; therefore, each drop lost is 10 percent of the total contents and sperm numbers.

Place a sterile plastic sheath over the gun and seal it. Wrap the end in a paper towel to prevent exposure to the sun and to maintain sanitation. Then place the end of the gun in your shirt or pants pocket to maintain temperature on the way to the cow.

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During hot weather, do not place the insemination gun in direct sunlight or on hot surfaces.

After the gun is readied, clean the region of the vulva to prevent contamination of the inner reproductive tract. If you are not completely sure the animal is in heat, pick up the cervix and uterus and see if you get a clear mucous from the vulva. This is a good sign she is in heat.

Insert the gun in the cow upward at a 30-degree angle. This avoids entering the bladder. Remember that inseminating the cow does not require much force or pressure. Do not poke around with the gun. Try to move the cervix around and bring it to the gun. Take your time, relax and concentrate on your technique. If the cervix is over the rim of the pelvis, pull it back toward you where it is easier to insert the gun. If you are getting caught in the folds of the vagina, try stretching the cervix away from you to free your gun and allow a clearer entry into the cervix.

Semen should be deposited in the body of the uterus. This area is less than one-inch long and is about the size of a dime. It is located immediately in front of the cervix. A common mistake is to deposit the semen several inches into the right uterine horn. Feel the end of the gun with your finger when you are just outside the cervix. Be sure the gun is passing through the cervix and you are not just stretching the vagina. When the tip of the insemination gun passes through the front ring of the cervix, it is in the uterine body.

Check the location by placing the index finger in front of the cervix. You should just be able to feel the tip of the gun. After you feel the tip of the gun, lift your index finger and slowly deposit the semen over a five-second period. Be sure your fingers are not misdirecting the flow of semen or blocking a uterine horn. Reposition the gun each time the animal moves. Count by thousands to five.

If the cervical mucus of a cow previously bred feels thick and sticky, the cow may be pregnant. On repeat services, it is best to deposit the semen just past the half-way point of the cervix. Be careful. If you find blood on your glove, be gentle. Concentrate on placement. Practice proper sanitation procedures. Don’t give up on the hard ones; they too will work.

Practice good insemination techniques. Consider retraining. It may help improve your herd’s fertility. Your cows can’t make up for your mistakes in improper semen handling and placement. And with fertility, paying attention to details will improve the overall results. Breeding in a healthy tract with proper technique at the right time with fertile semen will increase pregnancies in your herd. PD

—From Georgia DairyFax, January/February 2006

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