Three keys to planning the spring breeding season

By: Glenn Selk, Oklahoma State University Emeritus Extension Animal Scientist

Three key management concepts can help commercial cow calf operations improve the productivity of their cow herds.  However, planning and preparation must take place well in advance of the spring breeding season.  The key areas to consider include:  1) assess the bull power; 2) immunize the replacement heifers properly; and 3) breed the replacement heifers ahead of the cows.

Lets examine each one briefly in more detail.

Bull power:

Do you have enough bulls to meet the needs of the cow herd?  Very young, 12 month to 15 month old bulls should be placed with 10 – 15 females. Two year-old bulls can be placed with 18 – 24 females and experienced bulls should be able to breed 25 – 30 females or even a few more if in small breeding pastures.  Have the bulls recently passed a breeding soundness examination?  Arrange with your veterinarian a time to check the bulls for breeding soundness.  Research has indicated 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.  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.

Immunize the heifers:

Yearling replacement heifers should be immunized for respiratory diseases such as IBR and BVD.  Discuss with your veterinarian the type and the timing of the vaccinations.  If you choose to give the heifers a modified live vaccine for long-lasting protection against these viruses, heifers should receive this vaccination at least one month before the start of the breeding season.  This would also be good time to include other reproductive disease protection that may be recommended by your veterinarian.  Examples of other diseases that should be considered include leptospirosis and campylobacter (sometimes called vibriosis).

Breed the heifers ahead of the mature cows:

Yearling replacement heifers should be mated with bulls or bred artificially about  3 weeks to a month before the start of the breeding season for the mature cows.  Breeding the heifers early is important for two 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 as they are the females most likely to need assistance at calving time.

Naturally, there are other health, nutritional, and management chores that must be attended to during the time prior to breeding, but using these three concepts would aid greatly in improving the productivity of many Oklahoma commercial cow calf herds.