Avances en Producción Animal N" 16 (1-2): 203-209, 1991 
NOTA TECNICA

ANALISIS GENETICO PARA PESO Y LONGITUD DE ALEVINES DE TRUCHA ARCOIRIS, ONCORHYNCHUS MYKISS
GENETIC ANALYSIS FOR WEIGHT AND LENGTH IN RAINBOW TROUT FINGERLINGS, ONCORHYNCHUS MYKISS

ROBERTO NEIRA R.1, NELSON DIAZ P.2 XIMENA GARCIA F.1 y FRANCISCO ESTAY C.3

Departamento de Producción Animal
Facultad de Ciencias Agrarias y Forestales
Departamento de Ciencias Ecológicas Facultad de Ciencias
Universidad de Chile

Summary

Information on 140 and 171 days weight and length of rainbow trouts from 35 cohorts of wild (S), cultivated (P) individuas and their crosses are analyzed. In 10 such familias yearling weight and length were also measured.
Significant differences for these traits, between different genetics origins were found, with general means of 5.75 g and 2.10 g of weight and of 7.36 cm and 5.31 cm of length at 140 days of age for P and S individuals respectively. Corresponding figures for 171 days weight and length, in the same order, were 10.07 g and 2.85 g and of 8.76 cm and 5.98 cm respectively. Crosses showed, in general, intermediate values. High within cohort variability was observed with C.V. of 43-75% for weight and of 14-20% for length.
Heredability estimates, using intra-class correlation between paternal (MHP) and maternal (MHM) half sibs were obtained using sire and dam variance components, with average values of 0.54-0.56 for weight and 0.47-0.59 for length. Estimates obtained through a factorial design ranged between 0.45-0.49 for weight and about 0.54 for lenght. Standard errors were high, in general. Heredability for yearling weight and length were of 0.81 and 0.64 respectively.
Phenotypic correlation between weight and length were higher than 0.90 for all ages (P < 0.01).

Key words: Rainbow trout, heritability, fingerlings.

1.- Ing. Agr. Depto. Prod. Animal. Fac. Cs. Agr. Y Forest. U. de Chile.
2.- Prof. Biol. y Ciencias. Depto. C.s. Ecológicas. Fac. Cs. U. de Chile, Casilla 653. Santiago.
3.- Méd. Vet.