April is a good time to begin planning and preparing for the upcoming breeding season. Jack Whittier, Colorado State University’s beef extension specialist, has shared some suggestions for assuring greater success in the breeding herd.
— Line-up artificial insemination services and/or purchase replacement bulls at least 30 days prior to the start of the breeding season. New bulls should be brought to their new environment about a month prior to breeding. This gives them an opportunity to become adapted to their new environment before the critical start of a breeding season.
— Choose a breed and use expected progeny differences (EPDs) along with visual observation to select the bull that best fits the goals of your program.
— Have a veterinarian perform breeding-soundness evaluations on all bulls to be used this year. Research indicates that one of every six bulls will be questionable or unsatisfactory upon examination. It is important to find sub-fertile bulls in plenty of time to allow for the replacement bulls to be located and purchased for the upcoming breeding season or to allow time for the bull to be treated, if necessary, then re-checked.
— If you are going to use artificial insemination and/or estrus synchronization, make plans now and order needed supplies and semen. There are several options for estrus synchronization that are showing good results for both cows and heifers.
— Make final selection of heifer replacements based on performance, weight, pelvic size, and reproductive tract score.
— Immunize the heifers: Replacement heifers should be immunized for respiratory diseases such as Infectious Bovine Rhinotracheitis (IBR) and Bovine Viral Diarrhea (BVD). Consult with your veterinarian, but data suggests that a modified live vaccine provides longer protection against these viruses than killed vaccines. The heifers should receive this vaccination at least one month before the start of the breeding season. This would also be a good time to include other reproductive disease protection that may be recommended by your veterinarian. Examples of other immunizations that should be considered include leptospirosis and campylobacter (sometimes called vibriosis).
— Continue supplemental feeding as needed.
— Spring or "branding" work is usually scheduled for late April or May. Consult with your veterinarian about vaccines and health products your herd needs.
— Consider providing magnesium oxide in the mineral mix until daytime temperatures are consistently above 60 degrees. This may be particularly important this spring due to the amount of winter and early spring moisture Colorado has received and the earlier-than-normal green-up in many parts of the state.
— Identify calves with an eartag and/or tattoo while calves are young and easy to handle and record dam’s identification number and birth date. Commercial male calves should also be castrated and may be implanted according to product recommendations. Castration and dehorning are less stressful when performed on young animals. Registered calves should be weighed during the first 24 hours.
— Breed the heifers in a short breeding season: Yearling replacement heifers should be mated with bulls or bred artificially in a short (42 to 45 day) breeding season. Some producers like to breed heifers starting about a month before the start of the breeding season for the mature cows. Breeding the heifers early is important for two possible reasons. Two-year-old first calf cows normally take longer to return to heat cycles after calving than do older cows. Therefore if they calve early, then when they rebreed, they are in synchrony with the rest of the cows in the herd as they deliver their second calf.
In addition, the manager can watch the heifers more closely early in the calving season and give them additional attention. First-calvers are the females that are most likely to need assistance at calving time. One draw-back is that this extends the length of the calving season.