by Daniel Mallory, University of Missouri Regional Livestock Specialist

Prior to the start of the breeding season cattle producers must consider a very important examination of their natural service bulls, the breeding soundness examination (BSE). This exam should be conducted on an annual basis at least 60 days before the start of the breeding season, to allow for retesting or replacement. The BSE is made up of three components; structural soundness, reproductive exam, and semen quality. Veterinarians will evaluate these areas and determine if the bull is satisfactory or unsatisfactory or if the bull needs to be re-evaluated. This examination could potentially assist in avoiding a disaster, by eliminating infertile bulls which would result in open females. Another very strong component to a BSE is libido and veterinarians do not have the time to evaluate this chute side so it is strongly encouraged that satisfactory bulls are monitored during the breeding season to ensure that they are doing their job. If bulls are purchased it would be wise to ask for a copy of the BSE to insure optimal fertility.

Tools that cattle producers can use during the breeding season are estrus synchronization (ES) and artificial insemination (AI). These technologies offer beef producers the means to introduce proven superior genetics into their herds, shorten the calving season, and increase calf age and uniformity.

Advantages of using AI

• Shorter calving season resulting in a more uniform calf crop when also synchronizing estrus

• Ability to use superior bulls that otherwise could not afford

• Improve production traits (mating cows to specific sires)

• Reduce the number of herd bulls needed

• Increased genetics for replacement heifers

For commercial producers this could mean increasing weaning weights, improving post-weaning performance, enhancing carcass value and more productive replacement heifers. Starting an AI program will more than likely call for more involvement in the management of the cow herd. To be successful, a producer should follow these tips:

• Pre-breeding vaccinations or de-worming should be completed at least 30 days prior to breeding

• Keep a steady to increasing plane of nutrition (rations less than16 percent protein)

• Cows should average 45 days postpartum prior to artificial insemination (AI)

• Cows and calves should be clearly and individually identified with legible ear tags and/or brands

• Individual calving dates should be recorded for each cow

• Only use natural service sires that pass BSE

• Only use AI sires proven to perform effectively in a fixed-time AI program

• Use AI sires that are genetically proven (EPD’s)

• Ensure AI technicians are scheduled for AI date and capable to perform task

• Check corrals, allies, and chutes to ensure proper functionality

Poor management in one or more of these areas could result in lower success rates.

In the past AI involved twice daily estrus (heat) detection, with time and labor being noted as the biggest reason for not adopting these technologies, researchers at the University of Missouri have developed fixed-time artificial insemination (FTAI) protocols. This allows producers to minimize the number of animal handlings (times through the chute) and inseminate cows at a predetermined, fixed time, eliminating the need to “heat” detect.

The cost of an AI program can be variable, depending on the method of estrous synchronization used, cost of semen and whether an AI technician is hired or the producer performs the inseminations. A reference to AI protocols can be found in any Beef Sire Directory, these reference sheets are put together by the Beef Reproductive Task Force based on several universities research.

Recent studies indicate that several estrous synchronization/AI programs cost less than natural service, especially with the increased costs of bull replacement and bull maintenance.

As a reminder AI breeding barns are available: contact Daniel Mallory at 573-985-3911 ( to make arrangements for your operation.