Sexual performance has been subjectively measured with a libido test during screening of rams before public sale and breeding at the U.S. Sheep Experiment Station from 1990 to 2000. The objective of this study was to determine whether sexual performance was genetically influenced. Sexual performance scores ranged from 1 to 6 with scores increasing from sexually inactive to highly sexually activ...

Aim. The quantitative genetics underlying correlated behavioural traits (''animal personality") have hitherto been studied mainly in domesticated animals. Here we report the repeatability (R) and heritability (h(2)) of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the h(2) of behavioural types by varianc...

Genetic parameters for test-day milk flow (TDMF) of 2175 first lactations of Holstein cows were estimated using multiple-trait and repeatability models. The models included the direct additive genetic effect as a random effect and contemporary group (defined as the year and month of test) and age of cow at calving (linear and quadratic effect) as fixed effects. For the repeatability model, in a...

Key external stakeholders: Dairy and beef farmers, Irish Cattle Breeding Federation (IC scientists. Practical implications for stakeholders: This study showed that IGF-1 has potential as a predictor of well documented association with a number of reproductiv weeks postpartum for IGF-1 could help identify cows that are balance, thereby providing valuable additional information fo for improved pr...

The heritability of the hematocrit in adult, breeding pied flycatchers Ficedula hypoleuca is examined in a southern European population across seven years to see the consistency, or lack thereof, of patterns found with the trait at fledgling age where no significant heritability could be detected. While the across-years repeatability of the trait in adult, breeding birds was low but significant...