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Semen volume and concentration are very variable.

Semen samples may be contaminated with epithelial cells, bacteria, and dirt especially when it dribbles through the prepuce and off preputial hairs.

Libido, mating ability, penile erectile function and the ability to ejaculate are not evaluated.

The technique avoids the potentially painful aspects of electroejaculation.

The extended penis may be held by the semen collector during rectal massage to facilitate collection of a clean semen sample. The semen collector must collect the cloudy fluid into a warm receptacle as it dribbles from the penis or prepuce. When the urethral muscle begins to pulsate the massaging action should be in synchrony with the pulsations. After removal of feces from the rectum, a longitudinal back and forth massage is applied mainly over the ampullae, drawing semen toward the pelvic urethra. This technique requires two people, one to do the massage and one to collect the semen. The collector with the AV is seated inside the dummy. (Courtesy of Minitube International).įigure 4. Mobile dummy designed for semen collection by AV. Bottom: The bull's penis enters the AV before thrusting (Photos courtesy of Gencor - The Genetics Corporation).įigure 3. Top: The semen collector grasps the penis through the sheath and directs it to the opening of the AV. The thrust should be vigorous to ensure an ejaculate has been collected.įigure 2. The bull will make seeking motions and thrust into the AV.

When the bull has mounted, the collector must grasp the penis through the sheath and direct it to the opening of the lubricated AV ( Fig. If cows are available, but not in heat, a tranquilizer may be administered to facilitate bull mounting and semen collection. 4 ), or a bull while the collection is being performed. Since semen collection by AV imitates natural breeding, the bull must mount either a cow in heat, a steer ( Fig. Bulls to be collected by AV must be halter broken and should be nose ring trained. Two people are required for bull semen collection by AV, the bull handler and the semen collector who carries the AV. Bovine artificial vagina ready for semen collection. A small amount of non-spermicidal lubricant is applied to the inner liner before the collection is performed.įigure 1. Pressure is adjusted by adding air through a valve in the rigid casing until the AV liner protrudes slightly from the ends.

AV pressure is also an important factor for obtaining ejaculates of optimum quality.

Bulls for semen collection require an AV temperature of 42 - 50☌. After all the AV components are put together, the space located between the rigid casing and the inner rubber liner is filled with warm water. The usual components of a bovine AV include a rigid casing, inner rubber liner, rubber bands, valve, director cone, semen vial and warming bag ( Fig. This method is used almost exclusively in AI centers for practical reasons and because it produces physiological semen samples. Semen Collection by Artificial Vagina (AV) There are different methods that can be used to collect semen from bulls. Semen Collectionīulls are ready for semen collection and freezing procedures after they have passed a complete physical examination, the required federal health tests and a breeding soundness evaluation. This document reviews the steps performed for freezing bull semen in straws, beginning with semen collection through storage in liquid nitrogen tanks. Frozen semen in 0.5 ml or 0.25 ml straws has become the universally accepted unit of storage and transfer of bovine genetics to cattle producers. Artificial insemination (AI) has contributed enormously to the genetic improvement of beef and dairy cattle in the last 50 years.