The AI industry recognizes an ethical obligation and also an economic and genetic need to practice excellent husbandry methods. From an operational standpoint, the role of a genetically superior bull is to produce quantities of fertile spermatozoa for transmitting superior traits. To maximize the superior bull's potential, AI centers make significant investments in labor, feed and facilities to provide optimal care for the bulls. Nutritionally correct rations and attention to individual health to reduce physical stress are provided. The AI industry recognizes that sound animal husbandry practices may increase the longevity and productivity of these bulls.

Bulls are housed in clean, well-lit, ventilated buildings or outside in facilities that protect them from inclement conditions. Social interaction both visually and vocally is permitted by housing design. Bulls are raised and cared for by dedicated employees.

Human safety and animal safety are two prominent concerns underlying the management practices of AI centers. By virtue of their size and disposition, bulls may be considered one of the more dangerous males of the domestic species. Therefore, management procedures are designed to protect human life as well as provide for bull welfare.

TRANSPORTATION

Bulls normally first come under the care of AIC personnel when they are transported from the farm or ranch of origin to the AIC facilities. During transit it is recommended that adequate protection be provided from adverse environmental conditions. Procedures intended to minimize stress or injury of bulls should be followed during their transport to and from the facilities of an AIC or between the facilities of the AIC. Individuals transporting bulls need to be knowledgeable in the basic care of bulls. The transporting vehicle must be safe and allow for adequate space and ventilation for the bulls. During extended trips the animals must be periodically examined for evidence of injury or illness. Veterinary care for bulls in transit should be provided as necessary. Feed and water are to be provided in accordance with good husbandry practices. Care is observed in loading and unloading of the animals. Animals are transported to the AIC in clean and disinfected livestock trailers.

DISEASE SURVEILLANCE

The addition of new animals (bulls, mount animals) to a herd presents an opportunity for infectious disease to enter the resident population. Procedures necessary to prevent the introduction of potential diseases into the AIC must be followed.

The "Certified Semen Services (CSS) Minimum Requirements for Disease Control of Semen Produced for AI" provides a minimum industry standard for AIC health management. These requirements include testing and examination of bulls prior to their entry, during an isolation period and semi-annually throughout their residency at the AIC.

Animals that do not satisfactorily meet the pre-entry and isolation health testing requirements pose a potential threat to the health of the resident herd and shall be denied admittance. However, successful completion of the isolation health testing protocol will allow animals to finally enter the resident herd where they will continue to undergo continuous surveillance testing semiannually or as specified by CSS. Mount animals are required to undergo the same health testing regimen as bulls.

SIRE HYGIENE AND HANDLING

Sire hygiene and handling refer to the conditions and practices necessary to establish and maintain the health of animals.

Each AIC follows established procedures to insure sanitation and avoid transmission of potentially infectious material. Once a bull has been accepted, the primary objective is to maintain its optimal health and safety. Normally, young bulls are identified, receive a veterinary examination, and are treated to prevent specific diseases after arrival at the isolation facility.

Isolation premises should be washed and disinfected prior to the admittance of each new group of animals. Animals exhibiting any signs of illness upon arrival or during the isolation period need to be removed to a separate area.

Internal surfaces of the housing and pens allow for effective cleaning and disinfection.

In the semen laboratory and AV preparation area the counter tops and equipment need to be routinely washed and disinfected.

The walls and concrete flooring of the collection area are cleaned and disinfected on a regular schedule. Non-concrete flooring should be routinely misted with an appropriate disinfectant.

Visitors coming onto the AI center premises should be required to wear protective footwear to avoid transmitting potential organism to the AIC animals.

Within a facility, bulls are moved from one area to another for semen collection, facility cleaning and to maintain bull hygiene. Bulls may be led by handlers in alleyways, or at other times a series of gates and pens create a passageway for trained dogs to "move" the bulls. Mechanical devices may also be used to "walk" the bull, either for exercise or movement within a facility.

Physical restraint of a mature bull is required for health tests, veterinary examination and proper hoof care. Generally, bulls are restrained in locking stanchions or haltered.

ENVIRONMENT AND FACILITIES

Bulls are adaptable to a wide range of environmental conditions. Basic criteria for a satisfactory environment include physical comfort, disease control, access to adequate nutrition and safety for bulls and handlers.

A variety of indoor or outdoor housing systems are used to provide for the needs of bulls. The type of housing system used will vary based on geographic location, age and collection status of bulls. The housing system selected should be considered acceptable if the basic needs of the animals are met satisfactorily.

Each bull should have adequate space and dry area to lie down comfortably. In "tie stall" facilities bulls may be tethered which allows the bull to lay down, stand, have limited movement, and to eat and drink unhindered. Stalls should be regularly cleaned and suitable bedding materials should be used.

Cattle can tolerate a wide range of ambient temperatures, however, housing should be designed to protect bulls from extreme heat or cold. Bulls housed outdoors should have access to shelter for protection from sun and severe weather. Enclosed structures should be properly ventilated or air conditioned to help provide a comfortable environment. Ventilation can be provided actively by mechanical systems or passively with windows and vents, depending on the building design

Internal surfaces of the housing and pens should allow for effective cleansing and disinfection. Also to avoid injury internal surfaces and fittings of buildings and pens should not have sharp edges nor projections. Various paints and/or preservatives which may be toxic should not be used on surfaces which the animals contact.

It is recommended that provisions be made for the segregation of sick or injured animals.

The essential mechanical equipment of the facilities such as waterers, ventilator fans, heating and lighting units, fire-extinguishers, alarm systems, etc. should be inspected regularly to ensure proper working condition. All electrical installations should be inaccessible to cattle and properly grounded.

The facilities and management procedures should provide safety for bulls and handlers. Fences should be designed in a way to contain bulls effectively. Bulls housed in groups should be dehorned to limit the potential for injury to other bulls. Handling procedures intended to provide control of the bull should be employed when bulls are moved. The facilities should be designed and lighted to permit effective visual inspection of the bulls. Facilities can be adequately adapted for the comfort of older animals with age related physical conditions (heat lamps, extra bedding, larger stalls, etc.).

In general, performance of the bulls should be the primary indicator of the adequacy of the environment.

FEEDING AND WATERING

Bulls should be fed a nutritionally balanced ration. This may be based on National Research Council (NRC) guidelines or adjusted per professional consultation. The feed ingredients should be of good quality; feed ingredients may vary among AI centers depending on availability and types of regionally grown feed commodities. Bulls may be fed once or several times daily.

Clean and good quality water must be readily available. Water heaters need to be provided in cold climates to prevent freezing.

VETERINARY AND PROFESSIONAL CARE

For bulls to achieve and maintain their optimum growth and semen production potential, they must remain in good health and physical condition. Various preventive medicine programs are conducted to maintain the health of bulls.

Bulls are regularly observed by trained and experienced personnel, as well as veterinarians, for clinical health problems or lameness. When a clinical abnormality, illness, or lameness is observed, the bull is evaluated and appropriate action taken. Veterinarians, licensed in their respective states, diagnose and treat disease or injury when such problems occur.

A major component of preventive medicine programs at AI centers is the semiannual (or annual for some diseases) surveillance testing for numerous bovine diseases. Regular testing provides increased assurance that seminal transmission of specific bovine disease agents will not occur. Testing procedures and specimen collections are conducted professionally so that accurate test results will be obtained.

Preventive medicine by specific vaccination programs may also be practiced in an AIC; however the bovine diseases prevented by vaccination may be selectively chosen. High security isolation can be provided as a substitute for some vaccinations.

Inherent in any genetic advancement or preventive medicine program is the accurate identification of all animals. Bulls are identified by their registration certificate which is unique to each animal by its color markings or ear tattoo. When a bull is accepted into an AIC, it is thereafter designated by a unique sire code number per the NAAB Uniform Coding System. The management of an AIC will identify each bull by its NAAB stud code number by applying either an eartag, tattoo, neck tag or leg band. Eartagging can be accomplished quickly and safely with various commercially available applicator products. Some eartaggers are disinfected between each animal; others are designed that do not have direct contact with the animal's ear tissue when the tag is applied.

To make handling and leading of the bulls safe for barn personnel, nose rings are applied to most bulls. Trained and experienced barn personnel can safely and quickly insert a bull nose ring when the bull is appropriately restrained and the proper tools are used. Sedation or analgesia may be appropriate for some animals and adequate healing time is provided.

Hoof care is an important segment of a complete bull health program. Facilities in which hoof examinations can be conducted, along with appropriate hoof exam and trimming equipment, should be available. Trained AIC personnel may then attend to bulls exhibiting lameness or provide preventive hoof care examination. Alternatively, the AIC should be able to transport a bull to a facility where hoof care can be conducted or call in a professional hoof care specialist.

Dehorning may be regularly conducted in some AIC management programs. Dehorning bulls of horned breeds provides increased safety to bull handlers and also to other bulls when bulls are maintained in group housing. However, there are situations when it is not practical or appropriate to dehorn bulls. For example, AICs may prefer bulls to be horned when bulls are tethered in individual stalls. There are also selected breed considerations or simply age situations wherein it is not practical to dehorn bulls. These differences must be recognized. When dehorning is conducted at an AIC, procedures should be performed according to standard accepted veterinary surgical procedures, including administration of local anesthesia.

Within the scope of usual AIC management, castration is obviously not a frequently performed procedure. However, there are circumstances when castration is required. One example would be to further utilize an otherwise healthy but inferior bull as a mount animal. While castration is not always required in this situation, it is an acceptable option available to AIC management. Other situations for unilateral or bilateral castration include diagnostic or therapeutic reasons pertinent toward the study or treatment of specific genital problems. When castration is conducted, it is performed according to standard accepted veterinary surgical procedures, including sedation or anesthesia.

Occasionally, the AI Center veterinarian may be required to euthanize an animal that has a debilitating injury or condition that is unresponsive to appropriate medical treatments with little chance for a successful recovery. In these situations euthanasia should be administered to eliminate pain and suffering of the animal. A publication from the American Association of Bovine Practitioners (AABP), entitled "Practical Euthanasia of Cattle" is an excellent reference on indications for euthanasia, decision making, considerations involving euthanasia and methods to be followed. This information is available from the "Resources" section of the AABP website at the following link: http://aabp.org.

SEMINAL COLLECTION

Seminal collection from bulls is basically a simple procedure. However, because of the nature of the AI industry, seminal collections must be accomplished under established guidelines and policies regarding health and cleanliness of bulls, and safety for bulls handlers. In addition to operating under these guidelines and policies above, all seminal collections must meet certain quantitative and qualitative standards. To achieve these criteria, certain methods and procedures of handling the bulls are followed.

Normally, the collection of semen is best accomplished by a work team consisting of the semen collector, bull handler and may include a mount handler. These individuals work together to provide for and control the appropriate stimulus situation(s) for the bull.

semen collector - Manages the artificial vagina and performs the actual collection of semen. This person is usually the leader of the team and determines when the bull is properly prepared and when the seminal collection can be safely taken. In addition, the collector must insure that procedures are hygienic and that semen is accurately identified.

bull handler - Handles the bull via a lead rope. This person must be responsible for keeping the bull under control and safely away from other persons and bulls in the collection arena. This person is also responsible for appropriate mount animal restraint unless the animal is managed by a separate handler.

mount handler - Handles the mount animal via a lead rope or halter. This person is responsible for keeping the mount animal under control while the bull is being prepared for collection.

Seminal Collection Procedure

Seminal collection procedures normally include; sexual stimulation, sexual preparation, and collection of the semen.

[Sexual Stimulation]


Providing a stimulus situation which elicits mounting behavior in the bull is termed sexual stimulation. The stimulation process starts by exposing the bull to a mount animal in a collection environment. The presence of other animals in this environment and various visual, olfactory, and auditory stimuli, sexually arouse the bull. When the bull is sexually aroused he will have an erection of the penis and will want to mount other bulls and/or a mount animal. (A mount animal is another bull or steer whose purpose is to sexually stimulate the bull and stand in a sturdy position as the bull mounts him, as if in a natural breeding situation). Cows are not excluded as mount animals but their use is not advocated. Depending upon the libido of the bull and the frequency of collection, the stimulation may be accomplished in a matter of minutes or it may take much longer.

[Sexual Preparation]

Sexual preparation is the intentional prolongation of sexual stimulation. It is achieved through a series of false mounts (allowing the bull to mount, but not ejaculate) and restraint, and ultimately results in an increase in the quantity and quality of sperm ejaculated. The type of preparation varies widely depending upon the libido and physical condition of the bull.

For all false mounts, the semen collector should be at the bulls side to hold the sheath aside so the penis does not come in contact with the rear quarters of the mount animal. This diminishes the chance of contaminating the penis and also serves to prevent possible injury. Due to physical and health conditions, especially rear limb and spinal disabilities, some bulls may need to be limited in the number of false mounts allowed. The seminal collection procedure for such bulls should be under the direction of a professional livestock person or a veterinarian.

[Collection of Semen]

The collector should work with the bull throughout the preparation procedure and determine the optimum time for seminal collection. Routinely the seminal collection is performed immediately after the false mounting regime is completed.

The semen is collected through the use of an artificial vagina (AV). This device is made to simulate the natural breeding situation as much as possible. Intromission and ejaculation into the AV are performed by the bull in a manner nearly identical to natural mating. Since the final ejaculation cascade results from tactile stimuli to the bull's glans penis, the temperature, turgidity and lubrication of the AV are important to successful sperm harvest. AV water temperatures between 40° and 60°C are common. A sterile and non-spermicidal lubricant applied to the upper one-third of the AV liner will improve the response of the bull and minimize penile abrasions. Normally the AIC will provide AVs of different length and diameter to accommodate differences among bulls. The AV is equipped in such a way that the semen drains into a collection vial. After the collection has been completed, the vial is removed, properly labeled and prepared for processing.

To prevent potential transmission of disease producing agents during semen collection, the hindquarters of the mount animal must be effectively and thoroughly disinfected between successively mounting bulls. In addition, AV equipment is thoroughly cleansed and disinfected or sterilized prior to each use. A separate AV or AV liner must be used for each ejaculate.

THE SEMINAL COLLECTION FACILITIES

Seminal collection from bulls should be performed using the proper facilities and equipment. The safety of the personnel and animals are of utmost importance.

Seminal Collection Arena

It is recommended the collection arena consist of an area large enough to accommodate the safe semen collection from one or more bulls. The size of the arena should be such that the individual bulls and mount animals can be led throughout the area without interfering with one another.

It is important that the collection area provide good "footing" for the bull and mount animal to prevent slipping and subsequent injury. Concrete should be avoided unless surfaces are grooved.

The passage way leading from the bull housing area to the collection arena should be equipped with a sturdy guard rail to allow the bull handlers to separate themselves from the bull. The railing is generally placed near the center of a walkway so that it allows the bull to be led on one side of the rail while the bull handler(s) walk on the opposite side of the rail. It is recommended the railing be built in seven to fourteen foot lengths with each length being separated by a gap or a safety man-pass of approximately fourteen inches. This safety man-pass provides the bull handlers the opportunity to switch from one side of the railing to the other should the need arise. The fourteen inch man-pass is of such size that the bull handler can easily pass through while a large bull cannot. It is also recommended that similar safety equipment and precautions be applied to the collection arena.

ALTERNATIVE MEANS OF SEMINAL COLLECTION

The use of electroejaculation as an alternative seminal collection method should be limited to those circumstances when the temperament or physical condition of a bull renders collection of semen by AV unsafe or impossible. If this method is applied in other situations, it should be employed only after a diligent effort to harvest spermatozoa via the AV has failed, including systematic trial of different teaser animals and collection sites. Casual substitution of this method for diligent collection room management is not recommended.

In situations where bulls display shyness of collection personnel, collection accompanied by use of a blindfold should be attempted before resorting to electroejaculation. This approach should be tried repeatedly before use of electroejaculation. Complete physical and behavioral evaluation are essential before electroejaculation is considered.

The practice of electroejaculation of young bulls that have failed to demonstrate normal libido is not recommended. Electroejaculation should not be used to compensate for congenital abnormalities of the reproductive organs that make intromission and/or normal ejaculation impossible.

Collection of semen by this method can be accomplished in a humane and safe manner providing consideration is given to the equipment employed, the site and method of restraint, and the training of the operator of the electroejaculator.

The electroejaculators used in CSS-approved AICs should be of the solid-state, low-amperage type with complete grounding of the electronics. Current output should not exceed one ampere at maximum power. Machines must be regularly maintained, with particular attention to possible short circuits. The use of rectal probes with ventrally oriented electrodes, hand-held, or finger electrodes are advocated to minimize extraneous skeletal muscle stimulation.

The restraint chute selected for electroejaculation should provide lateral immobilization. Ventral support may be provided for bulls affected with posterior paresis using leather straps or belts between both the thoracic and pelvic limbs and fastened securely to the chute frame. Chemical tranquillization can be employed prior to electroejaculation, but the drug and dosage utilized should be selected by the attending AIC veterinarian and administered under his/her supervision. Positive conditioning such as brushing or even feeding may relax the animal; any abusive treatment of the bull must not be tolerated.

Proper training of machine operators must involve the supervision by an experienced machine operator and/or veterinarian. The operator must be completely familiar with the instrument's controls, the chute, and the bull. The controls must always be checked to verify that the electrical output is nil before the electrodes are inserted into the bull's rectum. Clearing of fecal material from the rectum with a sleeved arm and use of a non-irritating lubricant are essential. Care must be taken to dilate the anus and rectum gently, not forcibly, and if a rectal probe is used, it must be inserted slowly so the rectal lining is not injured.

Consideration must be given to the temperament, physical condition, and response of the bull when determining whether to collect semen by this method. Considerable individual variation in response can be expected, and operators must terminate stimulation if the animal becomes fractious, loses its footing, or is in distress. Slow, methodical increases of power at the lower amperage levels usually produce ejaculation well below the maximum output of the machine. Stimulation frequency and level may also be minimized by a period of precollection sexual preparation of some bulls, either by massage of the pelvic genitalia or active preparation with a teaser animal. Following alternative collection procedures the probes and electrodes must be thoroughly cleaned and disinfected prior to next use.

Seminal collection by ampullar massage is another alternative collection method. This method has proven to be less consistent in harvesting semen of acceptable quality and should be employed only by an individual experienced in the methodology.

AIC management must support and foster humane considerations in the management of bulls, including the recommendations of technical staff regarding the unsuitability of particular sires for collection by electroejaculation. Livestock handlers in daily contact with the bulls are often the most astute judges of the temperament and physical response of bulls, and their evaluations of the response of individual bulls to electroejaculation should be solicited and heeded.

Revised June 2004