Resumen

FORTES-SILVA, Rodrigo et al. Genetic evaluation of Nile tilapia in naturals conditions of low temperature. Zootecnia Trop. [online]. 2010, vol.28, n.3, pp.395-401. ISSN 0798-7269.

Genetic parameters to design or optimize breeding programs for these body weights are lacking. To evaluate the potential of mass selection for growth, genetic parameters are required. The goal of this study was estimate genetic parameters of growth characteristics in Nile tilápia (Oreochromis niloticus) in naturals conditions of low temperature. Information on 800 full-sib provide by 20 families was used. Fishes were weighed every 12 ± 2 days until end of experiment (150 days). Proc Mixed was used to evaluate the variance and covariance components and to obtain heritability and correlations. Unicharacteristic model via REML, considering fixed effect the contemporary group (tank and sex) and genetic effect (animal) was used. Measurements for weight at 60 days (W60), weight at 150 days (W150), length at 60 days (L60), length to 150 days (L150), daily weight gain (DWG), daily length gain (DLG), Carcass (EC) and carcass efficiency (CE) were: 31,62g; 220,54g; 10,50cm; 90,60cm; 1,68g; 0,69cm; 83,89g; 0,87g respectively. High heritability and genetic correlation for body weight and eviscerated dressing Values of Nile Tilapia obtained in this study, can be used in future studies of animal breeding, intending to increase the proportion characteristics related to body weight

Palabras clave : estimation; genetics parameters; Oreochromis niloticus.