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Titolo:
INCREASING LONG-TERM RESPONSE TO SELECTION
Autore:
WRAY NR; GODDARD ME;
Indirizzi:
CARE OF VISSCHER PM,ROSLIN INST ROSLIN EH25 9PS SCOTLAND VICTORIAN INST ANIM SCI,LIVESTOCK IMPROVEMENT UNIT ATTWOOD VIC 3049 AUSTRALIA
Titolo Testata:
Genetics selection evolution
fascicolo: 5, volume: 26, anno: 1994,
pagine: 431 - 451
SICI:
0999-193X(1994)26:5<431:ILRTS>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
BREEDING SCHEMES; DAIRY-CATTLE; RATES; POPULATIONS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
27
Recensione:
Indirizzi per estratti:
Citazione:
N.R. Wray e M.E. Goddard, "INCREASING LONG-TERM RESPONSE TO SELECTION", Genetics selection evolution, 26(5), 1994, pp. 431-451

Abstract

Selection on estimated breeding value (EBV) alone maximises response to selection observed in the next generation, but repeated use of thisselection criterion does not necessarily result in a maximum responseover a longer time horizon. Selection decisions made in the current generation have at least 2 consequences. Firstly, they influence the immediate genetic response to selection and, secondly, they influence the inbreeding of the next and subsequent generations. Accumulation of inbreeding has a negative impact on future genetic response through reduction in future genetic variance and a negative impact on future performance if inbreeding depression affects the selected trait. Optimum selection decisions depend on the time horizon of interest. If this is known, then a breeding objective can be defined. A selection criterionis proposed in which the positive contributions of a selected group of parents to immediate genetic response (determined by their average EBV) is balanced against their negative contribution to future genetic response (determined by their contribution to inbreeding). The value assigned to the contribution to inbreeding is derived from the breedingobjective. Selection of related individuals will be restricted if thedetrimental value associated with inbreeding is high; restrictions onthe selection of sibs, however, is flexible from family to family depending on their genetic merit. A selection algorithm is proposed whichuses the selection criterion to select sires on 3 selection strategies, to select on i) a fixed number of sires; ii) a variable number of sires each allocated an equal number of matings; or iii) a variable number of sires allocated an optimal proportion of matings. Using stochastic simulation, these selection strategies for sires are compared withselection on EBV alone. When compared at the time horizon specified by the selection goal, the proposed selection criterion is successful in ensuring a higher response to selection at a lower level of inbreeding despite the selection of fewer sires. The selection strategy iii) exploits random year-to-year variations in the availability of individuals for selection and is successful in maximising response to the selection goal. The derivation of the value assigned to inbreeding is not exact and cannot guarantee that the overall maximum response is found. However, simulation results suggest that the response is robust to the detrimental value assigned to inbreeding.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 22:49:28