The productivity of herds may be negatively affected by inbreeding depression, and it is important to know how intense is this effect on the livestock performance. We performed a comprehensive analysis involving five Zebu breeds reared in Brazil to estimate inbreeding depression in productive and reproductive traits. Inbreeding depression was estimated for 13 traits by including the individual ...

Ongoing ambitions are to understand the evolution of costly polyandry and its consequences for species ecology and evolution. Emerging patterns could stem from feed-back dynamics between the evolving mating system and its genetic environment, defined by interactions among kin including inbreeding. However, such feed-backs are rarely considered in nonselfing systems. We use a genetically explici...

The influence of inbreeding depression on phenotypic traits of the Lizard canary from an Italian breeder was evaluated. The following traits were studied: birds’ life span, number of surviving offspring, and morphological traits (type of plumage, spangles, feather quality, breast, cap, ground colour, wings and tail, eyelashes, covert feathers, beak, legs and feet, habits, and size). The effects...

Studying associations between mating system parameters and fitness in natural populations of trees advances our understanding of how local environments affect seed quality, and thereby helps to predict when inbreeding or multiple paternities should impact on fitness. Indeed, for species that demonstrate inbreeding avoidance, multiple paternities (i.e. the number of male parents per half-sib fam...

We present a phenotypic model for the evolution of self-fertilization in an infinite population of annual hermaphrodites for the case in which fitness and inbreeding depression vary among generations (e.g., due to fluctuations in the environment from year to year). Conditions for the evolution of selfing, mixed mating, and outcrossing are derived and are compared with results from numerical cal...

Inbreeding results from the mating of related individuals and is becoming increasingly important in domestic livestock populations. Inbreeding depression is the reduction of the mean phenotypic value, particularly for traits connected with reproduction or fitness (Miglior et al., 1992). Inbreeding depression has been shown to decrease milk production by approximately 9-26 kg of milk per lactati...

Optimal outbreeding theory predicts fitness benefits to intermediate levels of inbreeding. In the present study, we test for linear (consistent with inbreeding depression) and nonlinear (consistent with optimal outbreeding) effects of inbreeding on reproductive fitness in male and female Drosophila melanogaster. We found linear declines in fitness associated with increased inbreeding for egg-to...

Inbreeding is essentially the mating of animals that are related. Within the pedigree of the mated sire and dam, one or more animals will be in common; resulting in progeny with a certain level of inbreeding. The level of inbreeding will depend on the relationship between the two mated animals, with the closer the relationship, the greater the level of inbreeding that will occur in the resultin...

An inbreeding matrix is defined for populations with overlapping generations. In the short term it can be expressed in terms of a matrix specifying the passage of genes between the different age groups (and sexes) and a diagonal matrix whose elements depend on the number of individuals in each age group. Formulae for the inbreeding effective number are derived using matrix theory. A comparison ...

Understanding how inbreeding affects fitness is biologically important for conservation and pest management. Despite being a worldwide pest of many economically important cruciferous crops, the influence of inbreeding on diamondback moth, Plutella xylostella (L.), populations is currently unknown. Using age-stage-specific life tables, we quantified the inbreeding effects on fitness-related trai...