Computation of inbreeding rate (DeltaF) must consider that inbreeding is delayed with one generation with respect to the idealized population when addressed using individual inbreeding coefficients. The expression relating inbreeding in generation t with inbreeding rate F(t) = 1 - (1-DeltaF)(t) should be more correctly written in real animal populations as F(t) = 1 - (1-DeltaF)(t-1), as changes...

Understanding the sources of variation in inbreeding depression within populations is important for understanding the evolution of selfing rates. At the population level, inbreeding depression is due to decreased heterozygosity caused by inbreeding, which decreases overdominance and increases the frequency of expression of recessive deleterious alleles. However, within individual families inbre...

Mature weight (A) and rate of maturing (K) were estimated for 283 Angus, 140 Hereford and 280 Shorthorn cows utilizing the asymptotic regression equation Yt=A(1-Be'Kt). The Yt was weight of the individual at age t; and B was an estimate related to early life weight changes and provided for a Yintercept (A-B). Each breed consisted of four inbred and two noninbred lines. Regression of estimated g...

Inbreeding results in more homozygous offspring that should suffer reduced fitness, but it can be difficult to quantify these costs for several reasons. First, inbreeding depression may vary with ecological or physiological stress and only be detectable over long time periods. Second, parental homozygosity may indirectly affect offspring fitness, thus confounding analyses that consider offsprin...

Pedigree. All individuals in a genetic population (such as a herd, family line, or breed) are related to some extent. One pedigree plan mates individuals more closely related than the average of the population; it is termed inbreeding. Long-term inbreeding in a closed herd may increase genetic uniformity, but inbreeding usually reduces performance, especially in fertility and survival. This is ...

studbook information collected from 1988 to 2011 in jafarabad breeding station of moghani sheep, north-west of iran, related to 9,457 lambs were used to study the genetic diversity and to evaluate the effectiveness of an implemented rotational mating scheme using pedigree analysis. lambs born during 2009-2011 were considered as reference population. means inbreeding and average coancestry for t...

Genetic and Phenotypic Effects Inbreeding can have dramatic effects on a herd. These effects are the result of individuals receiving identical genes from each parent. If the parents are related, it is more likely that they have genes that are identical. An individual receiving identical genes from each parent is said to be homozygous for that pair of genes. This would be desirable if the gene t...

Inbreeding depression is usually quantified by regressing individual phenotypic values on inbreeding coefficients, implicitly assuming there is no correlation between an individual's phenotype and the kinship coefficient to its mate. If such an association between parental phenotype and parental kinship exists, and if the trait of interest is heritable, estimates of inbreeding depression can be...

The aim of this study was to describe inbreeding and population structure in Sangsari sheep breeding station. For this reason, data from 7028 Sangsari sheep which were collected during 1987-2014 in Sangsari sheep breeding station located near to Damghan city, Semnan province were used. Lambs born during 2010-2014 were considered as reference population. The genetic structure analysis of the pop...