Enhanced individual selection for selecting fast growing fish: the "PROSPER" method, with application on brown trout (Salmo trutta fario).
Growth rate is the main breeding goal of fish breeders, but individual selection has often shown poor responses in fish species. The PROSPER method was developed to overcome possible factors that may contribute to this low success, using (1) a variable base population and high number of breeders (Ne >100), (2) selection within groups with low non-genetic effects and (3) repeated growth challenges. Using calculations, we show that individual selection within groups, with appropriate management of maternal effects, can be superior to mass selection as soon as the maternal effect ratio exceeds 0.15, when heritability is 0.25. Practically, brown trout were selected on length at the age of one year with the PROSPER method. The genetic gain was evaluated against an unselected control line. After four generations, the mean response per generation in length at one year was 6.2% of the control mean, while the mean correlated response in weight was 21.5% of the control mean per generation. At the 4th generation, selected fish also appeared to be leaner than control fish when compared at the same size, and the response on weight was maximal (approximately 130% of the control mean) between 386 and 470 days post fertilisation. This high response is promising, however, the key points of the method have to be investigated in more detail.
Chevassus
Bernard
B
Laboratoire de génétique des poissons, Institut national de la recherche agronomique, 78352 Jouy-en-Josas, France.
Quillet
Edwige
E
Krieg
Francine
F
Hollebecq
Marie-Gwénola
MG
Mambrini
Muriel
M
Fauré
André
A
Labbé
Laurent
L
Hiseux
Jean-Pierre
JP
Vandeputte
Marc
M
D000818:Animals; D001824:Body Constitution; D001835:Body Weight; D001947:Breeding; D005260:Female; D005828:Genetics, Population; D008297:Male; D009035:Mothers; D012641:Selection, Genetic; D013223:Statistics as Topic; D014337:Trout / Q000235:genetics* / Q000254:growth & development*