Making the Best of Your Resources:

Bull Management Tips to Increase or Maintain Herd Production

Dr. Mario A. Villarino, County Extension Agent for Agriculture and Natural Resources.

              Resources, and livestock resources more specifically  are an important component of variables needed to be managed and evaluated constantly to maintain ranch profitability. When referring to bull management, Drs Sprott, Bruce and Carpenter explained: - It is often said that a bull contributes half of the production in a calf crop. This may be true for an average bull, but probably exaggerates contributions from a poor quality bull and dramatically underestimates those from a good bull. A good bull offers both high fertility and high genetic breeding value for one or more economically important characteristics, such as growth, calving ease, maternal value and carcass quality. Fertility in a bull is generally defined as the ability to impregnate females. Certainly that is a minimum requirement, but a bull with high fertility is able to impregnate more than the expected number of cows in a short breeding season. Such a bull has greater economic value than one of lesser fertility. If the bull also has a desirable genetic background, it could contribute more than just half the production in a calf crop. It has been told that the North East Texas beef industry made a major improvement when care was taken in proper bull selection.

              Properly managing bulls from weaning through maturity will boost their contributions to herd productivity. When selecting bull calves at or before weaning, breeders must carefully consider future genetic goals for the herd, and base their decisions on economically important characteristics. After bull calves are chosen, whether for retention as replacements or for eventual sale, their growth and well-being depend mainly on disease prevention and adequate nutrition. Diseases affecting both young and mature bulls are essentially the same as those of breeding females. Do not assume that vaccinating one of these groups will also protect the other. Vaccinate both males and females. Certain reproductive diseases (BVD and leptospirosis) can develop in the fetus while it is still in an infected female’s uterus, resulting in offspring that become carriers of the disease. To prevent this carrier status of leptospirosis, vaccinate females at rebreeding and again at pregnancy testing. Vaccinate bulls at least annually for all five serovars (5-way lepto) of leptosprosis and for campylobacter (vibrio). In some cases, vaccinations may be needed twice a year. Occasionally, vaccinations for BVD and other viral diseases are recommended, but producers should consult their veterinarians for specific recommendations for diseases prevalent in their areas. Buy bulls only from herds in which adequate disease-prevention measures are practiced, and administer booster vaccinations upon arrival at their destination. A one-month quarantine before placing with the remainder of the herd is advisable.

The following management techniques are recommended

to ensure that bulls are given the best opportunity to contribute

their fullest production potential and to reduce the

chances of low fertility:

■ Use bulls with acceptable genetic potential for economically

important traits such as growth, carcass

quality, maternal value and calving ease.

■ Control disease with appropriate vaccinations (consult

a veterinarian).

■ Provide adequate nutrition from weaning age through

maturity. Undernourished bulls are likely to have low

fertility.

■ An annual breeding soundness exam (BSE) should be

conducted on all breeding-age bulls about six to eight

weeks before the start of breeding. Do not use bulls

that fail a BSE.

■ Avoid bulls with small scrotal circumferences and

extremely pendulous sheaths.

■ Have bulls tested at least once for their fertility associated

antigen (FAA) profile. Highest fertility can be

expected from bulls with FAA on sperm.

■ Observe bulls throughout breeding for their ability to

mate. Perform serving-capacity tests when feasible.

Bulls with low serving capacity settle fewer cows than

high-serving-capacity bulls.

■ Use separate breeding pastures for bulls less than 4

years old. Running them with older bulls may cause

dominance problems, affording fewer chances for

young bulls to mate.

■ Cull bulls with poor vision, low semen quality, lack of

desirable conformation and those producing inferior

calves.

For more information on bull selection and management please contact the Hopkins County Extension Office at 903-885-3443 or email at mavillarino@ag.tamu.edu.

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