Open access publications in the SLU publication database

In this report the construction and the underlying calculations for the total merit index of the Swedish beef breeds are presented. The total merit index, which came into use in the routine genetic evaluations spring 2009, is built up by three sub indexes: the maternal index, the production index, and the birth index. The maternal index consists of the indexes for the maternal influences on calving ability and weight gain between birth and 200 days. In the production index the indexes for net weight gain, carcass fatness, and carcass conformation is included. The birth index is made up by the index for calving ability as a calf trait. The indexes for the individual goal traits are in the total merit index put together with relative weights calculated for each goal trait as the product of the economic value and the number of discounted expressions. The economic values for the goal traits were calculated with regard to the value of the genetic progress in the respective traits. Number of possible calvings and number of slaughtered animals in different generations and in different years were calculated and discounted to the time of covering/insemination. Viewpoints and desires from the breed associations to profile the breeds with regard to production, maternal and calving characteristics were also considered and the relative weights of the total merit index were adjusted according to the various breeds´ somewhat different breeding goals. With the intention to match the beef breeds in a Swedish cross breeding system the aim was to profile the breeds as paternal (Charolais) with high growth rate and good calving ability of the calf or maternal (Hereford) with focus on calving ability and milk production of the cow.