Replacement Heifers

The fall is the time of year when a great many head of calves are weaned. While many of these young cattle are marketed immediately and sold off the farm, others are kept in the herd as replacements. One of the most time-honored traditions in building and maintaining a cow herd has been retaining and developing heifers from within the herd itself. While many heifers are required to replace cull cows which no longer have a place in the herd, additional females may be retained to build numbers. Also, quality heifer calves from outside the herd may also be purchased and developed. It is estimated that about 30 percent of the heifer calves produced in the U. S. are retained and developed for cow herd replacements. Management of heifers during the development period can significantly affect their lifetime productivity and must be carefully planned.

According to Schoonover, cow-calf producers in the Great Plains operate under a variety of environments and conditions and require cows that will produce sufficiently well on the resources provided by a particular environment and climatic conditions with minimal assistance. Selections of each year’s replacements are critical but not necessarily difficult; their genetic capabilities can be no better than the base from which they are chosen. It’s just a matter of choosing heifers from cows that are producing above average calves, have calving ease, sound structure with no defects, and good health. In order to do this, good performance records should be kept to be able to identify those top performing cows and keep the heifers from them as replacements. The same goes for the replacement heifers. Keep good records of those replacements as well as having a management program in place to properly develop those heifers. Good management allows for a maximum number of heifers to be bred in the shortest possible time and ensures adequate growth prior to calving. Some factors to consider in developing replacements include heifer weight at weaning or time of selection, weight desired at breeding, and the time interval in between selection and breeding.

Another important aspect of replacement heifers is to have a planned health program so they can be properly immunized prior to introduction into the breeding herd. A good vaccination program for replacement heifers will help to increase reproductive efficiency. According to Hogg, there are six diseases that cause abortions and infertility in which animals should be vaccinated for: Brucellosis, Leptospirosis, Vibriosis, IBR (red nose), PI₃ (parainfluenza) and BVD (bovine virus diarrhea). In addition to vaccinations, worming and parasite control should also be considered. If worms are a problem in your area, it is recommended that replacement heifers be wormed 30 to 60 days prior to breeding. A veterinarian can determine the level of worm infestation by examining manure samples and will be able to prescribe an effective treatment if worms are a problem. External parasites can be controlled with sprays and pour-ons specific for the type of parasite/s the animal may have.

For further information stop by your local extension office and pick up a copy of these extension articles: Selecting and Developing Replacement Heifers, Health Program for Replacement Heifers.