Bovine Reproduction. Группа авторов

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Bovine Reproduction - Группа авторов


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the most common mount animal unless the facility prefers the use of a phantom (dummy structure designed for supporting a mounting bull). Using cows as mount animals is discouraged because of the potential for penetration and contamination by the bull. Mount animals should have their hair closely clipped from the hindquarters, allowing for ease of cleaning and disinfection, which should be accomplished after every use. The process usually requires at least two people and preferably three. One person is assigned the mount animal, which is usually haltered or handled by nose ring. This person's responsibility is to position the mount animal for mounting and to assist in keeping it in position during collection. In large facilities there is also a bull handler who may have the bull haltered or tethered to control him during the mounting process. Most beef bulls in custom studs are free to mount the jump animal. Lastly, the semen collector manages the AV and is in charge of the entire collection area (Figure 12.4). It is this person who ensures the sample is properly identified and collected hygienically and is responsible for the safety and welfare of the team as well as the animals.

Photo depicts collection area.

      The procedure of semen collection is rather straightforward. Several bulls are usually penned separately along a “bull alley” facing the collection area. Mount animals are allowed to move along in front of the bulls in order to initiate some arousal. The bulls are allowed to observe other bulls mounting and being collected from this vantage point. It can be very evident that bulls in the bull gallery are aroused by the amount of vocalization that occurs as a bull is being collected.

Photo depicts proper technique for collection of bull semen.

      The preparation of the AV is important as the tactile sensation received by the bull is paramount to his semen production. It should simulate the natural breeding act as closely as possible. The AV is constricted, with a ridged tube that has a port allowing water to be added between the rigid structure and a latex liner. Within this liner another is placed to facilitate collection of the semen from the bull. This liner has a tapered end that allows the inclusion of a glass or plastic receptacle that will serve to hold the collected semen sample. Water added to the water jacket should be in the temperature range 40–60 °C and varies according to the preference of the bull; this has to be determined by the semen collector. Also, the amount of water within the jacket determines the rigidity of the liner, which can impact the bull's reaction to the AV. It is very important that a sterile non‐spermicidal lubricant be applied to the upper one‐third of the AV. This improves sensation and reduces the possibility of abrasive injury to the bull's penis.

      For those bulls that are too fractious or are incapacitated and unable to jump a mount animal, the collector has the option to use an electroejaculator. Although it is discouraged in the semen production industry, it may be used when all else fails. Usually the bull will produce a slightly less concentrated ejaculate and with the potential for a somewhat higher abnormal sperm count. However, with proper stimulus (rectal massage of the ampulla and seminal vesicles) adequate semen may be collected for processing. Massage of the pelvic genitalia alone usually does not produce adequate semen product for processing and is discouraged in the industry.

      Lameness

Photo depicts a well-designed work area for performing lameness examinations at a custom stud. Note the hydraulic tilt table and footbath in foreground. Photo depicts assisting in preparation of hoof block application.

      Treatment of issues such as foot rot or hairy heel wart may best be treated via footbath or topical therapy. The more stubborn infections may require antibiotics and periodic topical antibiotic bandages. If lameness persists after a few days of therapy, it is always recommended to question the original diagnosis and reinvestigate the problem.

      Occasionally, a diffusely swollen limb is observed associated with a joint (most often a tarsus) with accompanying pyrexia, which can signal initiation of septic arthritis secondary to a generalized bacteremia. These are usually consequences of some kind of stress, most often change of feed or feeding methods. Any bull presenting with generalized cellulitis in a limb should be considered a medical emergency. Most bulls are not weight‐bearing and can be difficult to deal with in local settings, so it is often better to refer these cases to a facility capable of handling this kind of care.

      Penile Injuries


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