Issue |
Genet. Sel. Evol.
Volume 34, Number 1, January-February 2002
|
|
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Page(s) | 23 - 39 | |
DOI | https://doi.org/10.1051/gse:2001002 |
Genet. Sel. Evol. 34 (2002) 23-39
DOI: 10.1051/gse:2001002
Non-random mating for selection with restricted rates of inbreeding and overlapping generations
Anna K. Sonesson and Theo H.E. MeuwissenInstitute for Animal Science and Health (ID-Lelystad), P.O. Box 65, 8200 AB Lelystad, The Netherlands
(Received 24 November 2000; accepted 8 August 2001)
Abstract
Minimum coancestry mating with a maximum of one offspring per mating
pair (MC1) is compared with random mating schemes for populations with
overlapping generations. Optimum contribution selection is used,
whereby
is restricted. For schemes with
restricted to 0.25% per year, 256 animals born per year
and heritability of 0.25, genetic gain increased with 18% compared
with random mating. The effect of MC1 on genetic gain decreased for
larger schemes and schemes with a less stringent restriction on
inbreeding. Breeding schemes hardly changed when omitting the
iteration on the generation interval to find an optimum distribution
of parents over age-classes, which saves computer time, but inbreeding
and genetic merit fluctuated more before the schemes had reached a
steady-state. When bulls were progeny tested, these progeny tested
bulls were selected instead of the young bulls, which led to increased
generation intervals, increased selection intensity of bulls and
increased genetic gain (35% compared to a scheme without progeny
testing for random mating). The effect of MC1 decreased for schemes
with progeny testing. MC1 mating increased genetic gain from 11-18%
for overlapping and 1-4% for discrete generations, when
comparing schemes with similar genetic gain and size.
Key words: mating / overlapping generations / selection / rate of inbreeding / genetic response / optimum contribution
© INRA, EDP Sciences 2002