Relationship between polledness and traits used in the breeding objectivesfor German Fleckvieh

The objectives of this study were to analyse the relationships between the different genotypes for polledness of German Fleckvieh bulls and traits whi ch are included in the breeding goals of German Fleckvieh. The data include d 15 homozygous (PP) and 15 heterozygous sires (Pp) which were compared wit h 4711 horned test bulls (pp). The model took into account the effects of p olled-genotype, birth year, their interaction and the percentages of Red-Ho lstein and of Angus blood proportion as linear covariates. By comparing the breeding values it was found that polled sires were inferior in milk, fat and protein yield, fat percentage and the standardized relative breeding va lue for milk traits (RZM) to the horned pp-bulls. The mean RZM amounted to 69 in PP- and to 77 in Pp-sires, respectively, while the horned bulls showe d a mean RZM of 100. In the paternal component for fertility the polled PP- sires were significantly superior compared with the horned sires. Polled bu lls achieved a mean relative breeding value of 106 (PP) and 103 (Pp), respe ctively, while the corresponding breeding value of the horned bulls was 99. The polled bulls showed higher scores in traits like muscularity and type while horned bulls reached higher scores for traits like stature and udder. A further result found in the analyses was that polled bulls were inferior in the total breeding value for meat performance and the breeding value fo r net gain when compared with the horned bulls. It could be not clarified w hether these differences were caused by linkage, pleiotropic effects or oth er genes located on many other chromosomes. Concluding the results it Is re commended to produce heterozygous Pp-sires preferentially by top crossing P P- or Pp-dams with pp-sires and to select in later generations top ranking Pp-animals for intercrossing. Using this strategy traits of the breeding ob jectives should be improved without loosing the polled gene in these German Fleckvieh lines.