Summary Analyses were conducted to estimate the influence of environmental effects, the genetic determination of retained placenta and its genetic and phenotypic relationships to some production and reproduction traits. Data were recorded in an experimental Simmental herd in Lower Austria. After applying restrictions, 2895 records of first and 2082 of second calving remained. For estimation of variance–covariance components a REML procedure based on an animal model was used. All estimates for heritabilities and phenotypic correlations of threshold traits were transformed to a hypothetical underlying normal distribution. The estimated heritabilities of retained placenta at first and second calving were 0.14 and 0.07 with a genetic correlation of 0.79. For twinning rate the corresponding figures were 0.19, 0.02 and 1.00, respectively. High genetic correlations were estimated for retained placenta and birth weight of calf at first parity (0.49) as well as between retained placenta and twinning rate at second calving (0.99). The estimated genetic correlations between retained placenta at first and second calving and first lactation milk yield were 0.14 and 0.56 and between retained placenta at first calving and subsequent days open 0.54. Phenotypic correlations were mostly equal in sign but substantially smaller than the corresponding genetic correlations. No significant genetic cytoplasmic effects could be found for retained placenta. There was strong evidence (p < 0.001) that twin‐births, calving difficulties (dystocia) and relatively short and long gestation periods substantially affected the incidence of retained placenta. Partial and complete retention of the placenta at first calving led to an increase of 34 and 4 days open (p < 0.001), respectively. The estimated decrease of first lactation milk yield (250 days) was 67 and 128 kg due to partial and complete retention of the placenta (p = 0.154). The results obtained suggest that the genetic determination of placental retention is strong enough to be considered in breeding strategies even if its heritability should be somewhat lower under field conditions than in the analysed experimental herd. Zusammenfassung Nachgeburtsverhaltung: Nicht‐genetische Effekte, genetische Determinierung und Korrelationen zu relevanten Leistungsmerkmalen beim Rind Ziel der vorliegenden Untersuchung war die Schätzung der genetischen Determinierung und des Einflusses nicht‐genetischer Effekte auf zeitliche Unterschiede im Abgang der Nachgeburt beim Rind, sowie deren genetische und phänotypische Korrelation zu relevanten Milchleistungs‐ und Reproduktionsmerkmalen. Für die Untersuchung standen die Milchleistungsprüfergebnisse der Jahre 1972 bis 1995 von Tieren der Fleckvieh‐Versuchsherde der niederösterreichischen Bundesversuchswirtschaft Wieselburg zur Verfügung, bei denen das Merkmal ‘Nachgeburtsverhaltung’ erhoben worden war (2895 bzw. 2082 Erhebungen für 1. bzw. 2. Abkalbung). Die geschätzte Heritabilität für das Merkmal Nachgeburtsverhaltung betrug für die 1. und 2. Abkalbung 0.14...

Field data of the Austrian Simmental population were analysed using restricted maximum likelihood (REML) with an animal model where additive direct, additive maternal and cytoplasmic effects were treated as random and the effect of the year of first calving as fixed. Traits analysed were milk yield, fat and protein content, persistency, days open and herd life. All dairy traits were pre-adjusted for best linear unbiased prediction (BLUP) herd-year effects, milk yield additionally for season, age at first calving and days open. After applying specific data restrictions, the number of records for the various traits ranged from 3360 to 51889. Identification of cow lineages was based on pedigree information from the official milk recording scheme, with a span of at least four and up to 16 generations. The number of lineages per trait varied and ranged from 484 to 3195, with an average size of 15 members (for herd life 7). Evaluations of the relevant variance components for the dairy and fitness-related traits investigated were separate for the first three lactations.The estimated variance components for cytoplasmic effects were close to zero for all dairy traits with the exception of first lactation milk yield, where a significant value of 2.0% of the total phenotypic variance was found. Significant contributions of cytoplasmic lineages to total variance in all lactations, however, were estimated for persistency (2·6 to 3.8%), days open (1·8 to 2.9%) and for both true and functional herd life (4.6% each). The portions of additive maternal variance and covariance between additive direct and additive maternal effects on total variance were very close to zero for all traits investigated. The maximum differences between BLUP lineage effects were 373 kg for first lactation milk yield, 44 days for days open (first lactation), 1·6 and 2·8 years for true and functional herd life and, on average, 1·0 kg for standard deviation of test day milk yields (persistency) of the first three lactations.Removing the cytoplasmic effect from the model led to increased estimates of the additive direct heritability. Further model aspects such as interaction between additive and cytoplasmic gene effects and possible confounding between cytoplasmic and herd effects are discussed.