SPICKARD, Mo. — Bred beef heifers, replacements at the University of Missouri Thompson Farm cow herd, lined up at feeding looking like peas in a pod. They came from 20 years’ research on fixed-time artificial insemination.
Jon Schreffler, MU farm manager, showed the herd at an advisory board meeting April 24.
College of Agriculture, Food and Natural Resources scientists use the farm to make better breeding methods to be passed on to farmers by MU Extension, according to a university news release. The work never ends.
In a herd of 2-year-old cows, visitors saw some of this year’s spring calf crop. Schreffler said of 221 calves this spring, 80 percent are from AI sires. The FTAI protocols now taught by MU Extension give improved results. Calves look alike for a couple of reasons.
All cows in a herd bred on the same day deliver calves 283 days later, give or take a few days. With timed AI, most calves usually come in a 14-day window. Calving-ease breeding often brings calves a week or so early. Similar ages bring uniformity.
Uniformity also comes from the sire used in AI. Those can be from top in the breed. Usually, only one sire is needed.
Uniformity comes in selection of replacement heifers as well. Those are from the top female calves born into the herd. Over time, cow herd genetic quality improves.
On the herd tour, David Patterson, MU beef specialist, pointed out that all cows and heifers have been genetically tested. With a few drops of blood, DNA maps of heifers are taken.
In such tests, every female in the herd can be ranked top to bottom on a genetic index. Recent genetic tests allow putting a dollar value on each characteristic. Those are combined into a single dollar index. That makes culling replacements easy.