Using phantom groups to increase the accuracy of breeding values of Dohne Merinos upgraded from a commercial base to the pedigreed population

Abstract Text: Animals entering the recorded Dohne Merino flock from a commercial base lack pedigree information, resulting in underestimated breeding values for their progeny. Animals originating from a cross between F3 ewes and a stud ram were assigned to phantom groups according to four pathways also including the year of birth of the progeny of an F3 ewe. Such animals were analyse without phantom groups, or classified according to phantom groups with a maximum of 100 parents. Average annual breeding values were calculated for the progeny (F4) of F3 ewes mated to stud rams and compared to pedigreed animals, termed as RES. Body weight, clean fleece weight and fibre diameter were analysed. Phantom groups rendered genetic trends in F4 animals comparable to that of RES animals. Phantom parents should be included in the Dohne Merino genetic analyses so that progeny of F3 ewes are more likely be selected.

Keywords: Genetic trends