the objective of this study was to investigate the effect of inbreeding on lactation performance in holstein cows of iran.the pedigree file contained information of 1,025,281 animals born between 1965 and 2007.lactation performance records from march 2000 to april 2009 comprising 193,501calving events on 123,751 cows in 85 dairy herds were included in the data set. the potential consequent effe...

population mean heterozygosity (i.e. 12 data points). Both analyses were statistically significant, indicating that populations with low heterozygosity have relatively abnormal sperm. Two alternatives to inbreeding depression are consistent with this result: a third, unknown factor causes some populations to have low heterozygosity and relatively abnormal sperm; for instance, environmental hete...

The Sorraia horse is a closed breed with reduced effective population size and considered in critical maintained risk status. The breed exists in 2 main breeding populations, one in Portugal and one in Germany, with a smaller population size. A set of 22 microsatellite loci was used to examine genetic diversity and structure of the Sorraia horse breed and to compare individual inbreeding coeffi...

Inbreeding avoidance and asymmetric competition over resources have both been identified as factors favouring the evolution of sex-biased dispersal. It has also been recognized that sex-specific costs of dispersal would select for sex-biased dispersal, but there is little quantitative information on this aspect. In this paper we explore (i) the quantitative relationship between cost-asymmetry a...

Inbreeding with close relatives and outbreeding with members of distant populations can both result in deleterious shifts in the means of fitness-related characters, most likely for very different reasons. Such processes often occur simultaneously and have important implications for the evolution of mating systems, dispersal strategies, and speciation. They are also relevant to the design of br...

Although inbreeding can reduce individual fitness and contribute to population extinction, gene flow between inbred but unrelated populations may overcome these effects. Among extant Mexican wolves (Canis lupus baileyi), inbreeding had reduced genetic diversity and potentially lowered fitness, and as a result, three unrelated captive wolf lineages were merged beginning in 1995. We examined the ...

The traditional quantitative genetics model was used as the unifying approach to derive six existing and new definitions of genomic additive and dominance relationships. The theoretical differences of these definitions were in the assumptions of equal SNP effects (equivalent to across-SNP standardization), equal SNP variances (equivalent to within-SNP standardization), and expected or sample SN...

introduction the mating of related individuals produces an inbred offspring and leads to an increased homozygosity in the progeny, genetic variance decrease within families and increase between families. the ration of homozygosity for individuals was calculated by inbreeding coefficient. inbred individuals may carry two alleles at a locus that are replicated from one gene in the previous genera...