MHBA ANIMAL HEALTH SERIES: Bulls, babes and breeding

By Peggy Joseph-Potter RN, BSN, MHA

Springtime means new beginnings, whether you decide to calve in the winter or spring it is time to start planning for the next calf crop. Developing a timetable and getting cattle bred and rebred on schedule is an important component of herd management. Taking the time to analyze your herd and to choose a bull with traits that accentuate your program can be the difference between success and failure.
Whether you utilize your own bull, AI, or rent one, cattle condition, soundness and health must be considered. Reproductive disease can be carried either by natural or artificial means. Maintenance of a comprehensive vaccination program is essential for a quality-breeding program. Testing for diseases such as Tuberculosis (unless herd has been certified TB-Free), trichomoniasis, BVDV also helps to ensure a healthy outcome.
For those interested in obtaining calves through the AI process, semen is readily available from a number of breeders. It is best to obtain semen from a breeder who is known to meet the generally established health standards in caring for their herd. AI success requires timing, good record keeping and a competent inseminator. Whether you utilize your ranch veterinarian, a reproductive veterinarian or an AI service references and success rates should be a factor in your decision.
In 1970s, Certified Semen Services, Inc., CSS, was formed to qualify and monitor the production of “health certified semen.” Semen obtained through this method must meet very strict standards, including quarantine and the donors must undergo multiple health related tests during their internment. A number of qualified facilities are available throughout the United States; these services perform the required housing, testing, and monitoring of the prospective bulls. Only semen meeting these tough standards is allowed to use the CSS logo. The CSS international qualification can meet the requirements for the export of semen however, each country has its own set of standards; therefore, it is best to involve them early as these organizations have a wealth of knowledge and can walk you through the procedure.

Tuberculosis (TB)
While TB is not a reproductive, disease it can rapidly spread to your herd through the introduction of infected animals or contact with wild or domestic ruminate mammals. The Mycobactium bovis. M bovis, is transmitted by aerosol, ingestion, or breaks in the skin. Like leptospirosis and Brucellosis, humans can develop the disease through contact with a sick animal or ingestion of infected milk. Testing must be performed by a veterinarian and is required for the movement of animals in states not deemed as TB Free.

Infected bulls spread trichomoniasis, a true venereal disease. It can cause abortion in the pregnant cow, usually within the first trimester; however-late term abortions have been known to occur. The best defense against this disease is to utilize a virgin bull or one known to be tested by a veterinarian and deemed disease free. Semen is generally safer than live breeding as the freezing and dilution process reduces the effectiveness of the organism. A vaccine is now available to be use prior to the breeding season.

Bovine Brucellosis-Bangs Disease
Brucellosis, while rare, can have significant implications for livestock due to the threat of abortions; it is noteworthy if the cattle breeder also raises swine, sheep or goats. It was because of this great economic importance and the ability of the disease to cause undulant fever in humans, the United States government stepped in with vigorous elimination programs and now requires RB51 vaccine to be given to all female cattle between the ages of 4-8 months. Breeders who live near wilderness areas where their herds may encounter wild game need to be especially diligent in the protection of their livestock.

Bovine Leptospirosis
Leptospirosis is the most common cause of infectious abortions in cattle. It enters the cow through breaks in the skin and is spread by the urine of sick and carrier animals contaminating feed and water. About 70 percent of infected cows show little outward signs of illness, and they will continue to shed the bacteria in their urine for several months after recovery. Cows can abort even if they do not appear sick. Vaccinating with a product that covers the five most common types of lepto is your best defense against this disease.

Bovine Viral Diarrhea Virus (BVDV)
BVDV is a viral disease that can cause abortion, diseased calves and those with suppressed immune systems. BVD is the most prevalent bovine viral disease. It can be carried by affected animals, on clothing and vehicles. The virus can cause abortion at any stage of gestation, if the fetus survives it may continue to shed the virus as carrier or the state of BVD PI, remaining persistently infected throughout its life. Modified live vaccines are available and should be imperative for any herd health program.

Buetongue is a disease affecting cattle, goats and sheep. It is seasonal and is most prevalent in the southern and western United States. The disease is caused by a specific midge biting insect, Culiconides varipennis. Infected livestock can develop ulcers and erosion of the lips, tongue and dental pad; abortion of a pregnant animal is not uncommon. Livestock are known to carry it however, sheep are the most susceptible. Vaccine is available for sheep, but not cattle or goats. Bluetongue testing is required by some states for the sale of breeding bulls and for the export of semen. CCS and major sheep producing countries such as Australia require a negative titer.

Have a safe and productive breeding season!

Haynes, N. B. (1978). Keeping Livestock Healthly. North Adams, MA: Storey Publishing, L.L.C.
Thomas, H. S. (1998). Storey’s Guide to Raising Beef Cattle. Storey Publishing.

Peggy and her husband, Bob Potter, own and operate PJ Ranch LLC in Winton, California where she serves as the Vice President of Animal Health. They have been Miniature Hereford owners and active participants in the MHBA since 2002. She is also employed as a critical care nurse for a local medical center.

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