During the opening evening of Cattlemen’s College at the 2014 Cattle Industry Convention in Nashville on Monday, Dr. Jerry Lipsey outlined some basic criteria for selecting replacement females that will contribute to productivity and profitability in the herd.

Lipsey, now retired, spent a long career in academia at Michigan State and Kansas State Universities and with the Angus and Simmental breed associations. He began by saying the number-one indicator of profitability in a cow herd is stayability, or the fertile longevity of females. Less than half of the females entering most U.S. cow herds remain productive to six years of age, he says, and increasing that average can boost profits significantly.

But how to select for longevity in heifers?  Lipsey focused on four general groups of selection criteria. First he outlined what he calls “too/too,” meaning heifers that are too big, too small too fat or too thin. Standards for these measures can vary depending on cattle type and environment, but the rancher can use physical dimensions as a starting point in sorting heifers.

Next, Lipsey notes that years ago some producers noticed heifers born early in the calving season and that conceived early in their first breeding season tended to stay in herds longer. In recent years, university research from several institutions has confirmed that trend, showing a longevity and profitability advantage for early born, early bred heifers.

Crossbreeding, Lipsey says, improves fertility. Plant breeders recognized the value of heterosis, or hybrid vigor, in the early 1900s with the development of hybrid crop varieties. Using crossbred heifers can reduce the prevalence of genetic abnormalities that lead to embryonic death and generally improve fertility.

Finally, Lipsey outlined several “tipping points” that could lead to rejection of a heifer, such as foot, leg or udder problems.

In the Cattlemen’s College presentation, sponsored by Zoetis, Lipsey brought four Angus-based bred heifers into the arena for the audience to evaluate, and showed some information about the animals on the screen. After some discussion, the group generally agreed the heifers looked similar. None were too big, too small too fat or too thin. None had any apparent physical problems that would count against them as replacements.

But if someone wanted to select two of the four for a breeding herd, the numbers on the screen provided a clue to their potential stayability. Two of the four were born on October 6 and October 26, while the other two were born on November 10 and November 29. The earlier-born heifers both conceived after a single artificial-insemination (AI) breeding. One of the later-born heifers conceived from AI service while the other conceived later from natural service.

With other factors equal, Lipsey says, the two early born, early bred heifers likely would make more productive, long-lived members of the breeding cow herd.