Abstract. Title of the paper: Genetic parameters for reproduction traits in land sheep breeds
The objective of the study was a genetic statistical analysis of reproduction traits from 13164 lambings in German Grey Heath, 2260 in German White Heath, 12961 in German Polled Heath, 11258 in Bentheim and 3088 in Coburg. Reproduction traits included early lambing (≤ 550 days), late lambing (>550 days), first lambing interval, second lambing interval and total number of lambs born. Three different linear animal models were used for analysing of these traits. The heritabilities ranged from h² = 0.43 to 0.45 for the trait early lambing, between h² = 0.11 and 0.40 for the trait late lambing, between h² = 0.05 and 0.24 for the first lambing interval, between h² = 0.02 and 0.20 for the second lambing interval and between h² = 0.06 and 0.07 for the total number of lambs born. There were high additive genetic correlations between the first three parity numbers. Because of this, the parity numbers were analysed together using a repeatability model. Additive genetic correlations between early or late lambing and first lambing interval, early lambing and late lambing interval as well as between first and second lambing interval were moderate and negative.