Selecting for Disposition

You might know the ornery cows to look out for, but that doesn’t mean you should have to watch your back in the pasture. Disposition is a trait that can be genetically selected for, and considering its potential affect on profitability, it’s a trait you don’t want to overlook.

Angus breeders have submitted yearling cattle temperament scores on a 1-6 scale for several years now, creating an EPD (expected progeny difference) for disposition that can be used when making genetic selections. Like carcass traits, disposition is a moderate to highly heritable genetic trait.

The docility EPD is presented as a percentage, where a higher value is considered more favorable in terms of docile temperament. Since this is a threshold trait, herds that exhibit no problems in temperament will realize no improvement in selecting for favorable docility EPDs.

Example of use:

Docility EPDs (DOC) can be used as part of a complete selection program in the event that a breeder needs to make improvement in a herd’s cattle temperament. In this example, a 10-percentage-point difference exists between the EPDs for Bull A and Bull B.

On the average, assuming the two bulls were mated to comparable females, one would expect 10 more calves out of 100 sired by Bull A to have a temperament in the most docile score (score = 1) compared with calves sired by Bull B. In herds where temperament problems are not an issue, this expected difference would not be realized.

Bull A Doc EPD +13%
Bull B Doc EPD +3%
Difference 10%

Although the docility EPDs have been available as a research genetic evaluation on www.angus.org since the Spring 2008, these EPDs are now available on a weekly basis through the website and AAA Login (www.angusonline.org).

Source: http://www.angus.org/Nce/Documents/ByThenumbersDocility.pdf