LIMOUSIN TODAY October_LimToday_WEB - Page 22

Management Break Down the Mystery of Choosing Quality Replacement Heifers By Bruce Derksen At this time of year, many producers are considering the need to add replacement heifers to their cow herd. This is a routine process that often yields mediocre and mixed results, so the question might be, what can be done to take some of the guess work out of choosing the proper females to become a part of productive purebred and commercial cow herds? First, especially in the commercial markets, these heifers need to reach puberty as far in advance of the breeding season as possible, with the generally accepted weight of this taking place being 60- 65% of their likely mature weight. These specifics will offer them the best chance to successfully breed in the first 21 days of bull exposure, allowing the greatest likelihood of calving unassisted at the start of the calving season, which will in turn deliver time to recover and re-breed early in the second breeding season. Key traits that impact reproductive performance are fertility, calving ease, milk production with sound udders 20 | OCTOBER 2017 2018 and teats, longevity, good feet and legs, docility plus weaning and end- product weights. For commercial cattlemen, Limousin offers these sought-after traits in spades. It is easy to point out some obvious characteristics to quickly reduce the potential list of replacements, beginning with overly aggressive or wild heifers. Discard those with a history of heavy calves or hard troublesome calving on the mother’s side or females that are too large or small framed. Cull any that do not have sound feet and legs. Examine EPD records if they are available. For most commercial cattle they will not be, but there are still many things to look for to help deliver a greater percentage of high quality replacements. Assess confirmation, age, weight, and docility. Watch for depth of rib offering chest width and volume for increased eating capacity of poorer quality forages when necessary. Picking older heifers from older cows not only puts forth an early date of puberty and higher weights at breeding and calving times but perpetuates fertility by accessing the offspring of your most fertile cows. Longevity of the dam will very likely produce daughters that will also offer optimum pregnancy rates over time. Reproductive tract scores and measurements can also be used to rule out those calves with potential problems. If using EPD records extensively however, beware of over-selecting on a single trait year after year. For example, constantly choosing heifers for above average milk production can over time develop females that can’t meet their own nutritional needs when resources are limited or of poorer quality due to forage growing conditions. This will bring about the necessity of acquiring more costly quality feeds or risk having these cows fall behind in the breeding season and possibly being open. It is a good rule of thumb to begin with a somewhat larger group of heifers if forage and feed resources allow, as those projected to calve in the tighter window desired can be kept