Development of a maternal breeding goal and tools to select for this goal in UK beef production

摘要: A maternal breeding goal for the UK beef industry is described and economic selection indexes are developed to assist in of animals goal. The objective made up general ability traits, cow size, calving carcass traits. traits include interval, age at first calving, lifespan, weaning weight difficulty. calculations values outlined discounted genetic expression coefficients presented. Three illustrated. provides a dualpurpose index bulls produce replacement heifers most situations. second, hardy breed index, designed allow improved performance extensive environments. third, fertile herd allows producers who do not have fertility problems place more emphasis on objectives other than fertility. sample data from Limousin was used calculate estimated (EBVs) which were investigate response three when top 20% sires selected either with 50 or grand-maternal progeny no recorded progeny. Approximately two thirds seen heavily observed dual-purpose indexes. Bulls also using existing terminal sire resulting assessed index. There found be negative aspect though positive objective. presented as sum four subindexes emphasizing contribution ability, carcass, respectively total This further assists commercial decisions.