With summer heat stress not too far away and many looking at gender selected semen, now is a good time to review correct semen placement at AI.
After loading the gun, clean the region of the vulva to prevent contaminating the vagina and uterus. 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 discharge from the vulva. If the mucus is present, it is a good sign that she is in heat. It tells you estrogen is present, so you hope there is a big follicle ready to ovulate! Insert the gun into the cow upward ata 30-degree angle to avoid entering the bladder. Remember that inseminating any cow does not require much force or pressure. Do not force the gun. Try to move the cervix around and bring it to and around the gun. Take your time, relax and concentrate on technique. If the cervix is over the rim of the pelvis, pull it back toward you and guide the cervix to the gun. If the gun is getting caught in folds of the vagina, try stretching the cervix away from you to free the gun and allow easier passage to the cervix.
Deposit semen 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 that 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 your 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. Count seconds as you deposit the semen slowing in the animal. Be sure that your fingers are not misdirecting the flow of semen or blocking a uterine horn. Reposition the gun each time the animal moves. If the cervical mucus of a previously bred cow feels thick and sticky, the cow may be pregnant. On repeat services, it is best to deposit the semen just past the halfway point of the cervix. Be careful because you can inadvertently cause abortion.
Certain problems can occur. If you find blood on your glove, be gentler. Concentrate on placement. Practice proper sanitation procedures. While some cows are more difficult to inseminate, be patient and don’t give up. Years ago, researchers at the Pennsylvania State University developed radiography techniques to clearly evaluate insemination accuracy. These techniques overcame some of the limitations of the earlier dye techniques used to evaluate placement.
A study was reported in which 20 professional technicians and 20 owner/inseminators were evaluated using the radiography technique. Each person inseminated a total of 20 reproductive tracts. Radiographs were taken to access inseminating gun placement. The data showed that only 39 percent of the gun tip placements were in the uterine body. A total of 25 percent of the gun tip placements were in the cervix. Twenty-three percent were in the right uterine horn, and 13 percent were in the left uterine horn. Sixty percent of the semen was distributed either in the cervix or disproportionately in one uterine horn.
Only 40 percent of the semen was located in the uterine body or equally distributed in both uterine horns. The normal ratio of ovulation or release of eggs is approximately 40 percent from the left ovary and 60 percent from the right ovary. Because migration of embryos is rare, the pregnancy ratio should be the same: 40 percent left uterine horn and 60 percent right uterine horn. This is an easy way to have your palpator to check on the job you are doing with correct semen placement. Data on 100 or more pregnancies are required for a proper evaluation.
Practice good semen handling techniques. Use chilled tweezers that are as long as possible and no fingers. Fill tanks before you do a large number of breeding. Have one person thawing and loading, while another inseminates.
You may improve your herd’s conception rate. Retraining may be necessary tomaster the expertise required for proper gun tip placement and insemination.Your cows can’t make up for your mistakes in improper semen handling andplacement. If using gender selected semen and/or 1/4cc straws, you have even morereason to be more precise.
Source: Georgia Dairyfax