Performance Line
Modern Limousin Genetics : A Good Story for Feeder Calf Value
By Tonya Amen , National Center for Beef Excellence
Long known for their value as terminal sires , Limousin breeders have maintained the genetic value for those traits of interest , while also focusing on traits like docility that are important to their commercial customers and , as the industry has demanded , recent emphasis has been placed on marbling as well .
Much of this discussion will center around a look at genetic trend in the North American Limousin population of the last 20 years . Genetic trend is typically illustrated in charts like those in this article or in tables organized by year . Genetic trend charts and tables are simply the average EPD for animals born in each year for each trait . When evaluated over the years , a picture emerges of the traits that breeders have chosen to place selection emphasis on .
Limousin bull is expected to sire progeny who are nearly 11 percent more likely to have an acceptable temperament .
Table 2 shows the genetic trend for carcass traits from 1998 to present . While holding REA and FT fairly constant , carcass weight has increased drastically , a definite win for an industry paid on pounds . Additionally , it ’ s clear that recent focus has been placed on improving marbling , with a 64 percent increase in the average EPD since 1998 , with upward pressure accelerating in recent years . As quality grade continues to grow in its importance from a profit standpoint , this is a trait that should receive continued focus .
Table 2 : Genetic Trend – Carcass Traits ( from summer 2018 BOLT evaluation )
For example , Table 1 is an excellent illustration of what can happen when , as a group , breeders decide to make genetic improvement in a trait and use all the tools at their disposal to do so . Early on , Limousin breeders recognized that to meet the demands of their commercial customers , docility needed to be addressed . In the last 20 years alone , there has been a 130 percent increase in the average docility EPD . When put into practice , this means that compared to 1998 , the average
Table 1 : Genetic Trend for Docility ( from Spring 2018 NCE )
Table 3 illustrates the percentile ranks for NALF EPDs , as well as for some other British and Continental breeds . The vertical lines or “ whiskers ” on the plot show the variation in genetics for marbling among active sires in the breed . It ’ s encouraging to note that , while perhaps not reflected in the average , there are clearly active Limousin bulls with excellent genetics for marbling . Identifying and propagating these genetics will only allow for more improvement in
14 | AUGUST 2018