In Pakistan however,
random mating is not observed therefore coefficient of inbreeding denoted by F needs to be incorporated in the equation, i.e.,
Further more, Sonesson and Meuwissen (2001) proposed the minimum coancestry mating method which resulted in lower levels of inbreeding than
random mating, but F was approximately the same.
Random mating was used to produce the replacement herd.
We assessed the assumption of
random mating using measures of expected and observed heterozygosity.
It also indicated that the selection of animals could not be practiced in the proper direction and some sort of
random mating has been practiced.
The Wright's F statistics (1938)--[F.sub.it], [F.sub.st] and [F.sub.is]-- were calculated by ENDOG program (GUTIERREZ & GOYACHE, 2005), where: [F.sub.it] is the average inbreeding coefficient of population; [F.sub.st] represents the expected average inbreeding coefficient, estimated in hypothetic populations produced by parents
random mating, within each period, and; [F.sub.is] expresses the deviation generated from actual mating.
By using a large number of markers and progenies in the R[M.sub.10] from the cross of IHO x ILO, this study takes advantage of the effects of
random mating on identifying marker-QTL associations.
Weir's model for independence is a population with no common evolutionary history, complete
random mating, population homogeneity, no linkage, no selection, no mutation, and no migration--in other words, an idealized Hardy-Weinberg population.
Agreement with
random mating expectations was determined by the "exact HW test" (Guo and Thompson, 1992).
An important property of population subdivision (first noted by Wahlund 1928) is that even if each subpopulation is under
random mating ([F.sub.IS] = 0), the genotypic frequencies in the total population may deviate from Hardy-Weinberg proportions ([F.sub.IT] = [F.sub.ST] [not equal to] 0) because of variation in gene frequencies among subpopulations.
The values of the ISI range from -1 ("complete negative assortative mating", i.e., adults only mate with partners from the opposite strain or population), through an equilibrium at 0 ("
random mating", i.e., uniform sexual compatibility and therefore no mating preferences), to +1 ("complete positive assortative mating", i.e., adults only mate with partners from the same strain or population resulting in complete mating isolation).
The inbreeding coefficient showed a departure from
random mating, which is expected for a breeding flock and the artificial selection of breeding pairs.
Expected inbreeding coefficient, on the other side, was computed as the co-ancestry of the breeding animals assuming
random mating (Falconer and Mackay, 1996).
Most loci did meet the expectation of
random mating or, more specifically, independence of occurrence of pairs of alleles under Hardy-Weinberg equilibrium.
In contrast, positive assortative mating would result in a higher probability of natal philopatry for males than predicted under a hypothesis of
random mating (Rockwell and Barrowclough 1987).
