ESTIMATION OF GENETIC-PARAMETERS FOR DIFFERENTLY RECORDED FERTILITY DATA IN DAIRY-CATTLE

In the present study data consisting of 244,189 service periods of heifers, first calf cows, and older cows were analyzed. In addition to the fixed effects usually incorporated in models for the analysis of female fertility (herd, year, season, etc.), the data could be differentiated as electronically recorded via a handheld computer or recorded as usual, i.e. handwritten receipts had been issued. The means of the fertility parameters in both data subsets were clearly different. However, this could not be attributed to the recording scheme. Estimates of heritabilities in general were low and in agreement with literature values. Heritability estimates within subsets of the data did not show an effect of the type of recording. Differences in heritabilities were found between age groups with the highest values for heifers.