The effects of low and high altitudes on selective breeding have been studied by researchers in a paper for the Journal of Animal Science.
The paper, written by researchers from the University of Georgia, considers how cattle producers select animals for breeding and said it doesn’t always work out the way farmers intend, as “outside factors can affect how genes are expressed in each animal”.
Researchers from the University of Georgia focused on brisket disease, which they said was a major factor affecting the performance of Angus cattle living at high altitudes. The disease, researchers said, was triggered by high blood pressure and prevented cattle living at higher altitudes doing as well as those living closer to sea level.
The traits for cattle growth and health at different altitudes were analysed in the paper and it was discovered that the effects of weaning weight and post-weaning gain were not highly correlated across high and low altitudes. Information from the American Angus Association was used and researchers said that “sires should be evaluated differently based on the altitude at which they were intended to be used”.
Professor at the Institute of Genetics and Animal Breeding and co-author of the study Marek Łukaszewicz said: “Different sets of genes are required for successful performance in different environments. Some of those genes are common to many environments and some are not. With the computing capacity of today, it should not be a problem to introduce a few more traits to the national evaluations.”
Researchers said altitude was not traditionally reported in breeding statistics, but that producers should now make selection decisions based on a bull’s ability to survive its first year. Then, after considering survivability at high altitudes, producers should look at weight to select the best bull for breeding.
Ignacy Misztall, who also co-authored the study, said: “Direct observations on brisket disease would be best, but are unavailable. Comparison of survival and [post-weaning gain] at high and low altitudes allows for an indirect measure of adaptation to high altitudes.”