Improving the estimation of realized effective population sizes in farm animals |
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Authors: | JP Gutiérrez I Cervantes & F Goyache |
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Institution: | Departamento de Producción Animal, Facultad de Veterinaria, Avda. Puerta de Hierro s/n, E-28040-Madrid, Spain; SERIDA-Somió, C/Camino de los Claveles 604, E-33203 Gijón (Asturias), Spain |
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Abstract: | Computation of inbreeding rate (Δ F ) 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– ΔF ) t should be more correctly written in real animal populations as F t = 1 – (1– ΔF ) t ?1, as changes in allele frequencies occur in the equivalent co-ancestries in the previous generation. This simple approach is tested on simulated and real pedigrees thus demonstrating that: (i) the adjusted individual increase in inbreeding becomes stable in populations under random mating while the unadjusted parameter does not; (ii) regression of the unadjusted parameter over generations in pedigrees under random mating is highly significant while after correction it is not significant; and (iii) the variance of the adjusted parameter is reduced with the generations. |
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Keywords: | Effective size increase in inbreeding overlapped generations real populations |
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