Untersuchungen zur Eignung von Fleckviehbullen mit unterschiedlichem genetischen Milchleistungspotential für ökologisch wirtschaftende Milchviehbetriebe

Summary in the original language of the document

The present study examines milk yield traits and functional traits of Simmental dairy cows in organized biological dairy herds in Bavaria. Data from 3588 daughters of 239 bulls born from 1993-1994 were classified by relative breeding values for milk yield (MW) of sire (groups with low, average and high genetic potential for milk yield).
Milk, fat and protein yield in first and second lactation increased by 9-13% from low to high genetic merit group. No significant negative effects on fertility, calving ease and somatic cell count with increasing milk yield were observed.
Genetic correlations between milk yield traits on organic and conventional farms were about or above rg = 0,90, not indicating any serious genotype by environment interac-tion. Nevertheless further selection for milk yield may cause problems with increasing production level and studies on genotype by environment interaction should be im-plemented on a regular basis.