Genetic parameters and trends of morphometric traits of GIFT tilapia under selection for weight gain

Abstract

The main factor considered in breeding programs for fish is growth, which can be assessed in terms of a gain in either weight or body measurements. This study was undertaken to evaluate the morphometric traits of GIFT strain tilapia (Oreochromis sp.) selected for weight gain. The data set used contained information on 6,650 animals. The genetic values of 8,590 animals in a relationship matrix of five generations were predicted. The following morphometric measurements were evaluated: standard length; body depth and body width. Body area and volume were also calculated. Bi-character analyses involving morphometric traits were used to estimate (co)variance components. Heritability, larval and fingerling common environmental effects were estimated for each trait, together with the genetic and phenotypic correlations between traits. Bayesian procedures were utilised by Gibbs chains, and the convergence of the chains was tested using the Heidelberger and Welch method. Genetic trends were estimated by segmented regression of the fish breeding values of the generations considered in this study.Estimates of heritability (0.28 a 0.31) had moderate to high magnitudes for all traits. Genetic correlations between traits were all above 0.8, and the genetic gains were satisfactory from the third generation onwards. From the estimates of the genetic parameters and genetic gain the morphometric traits evaluated have good potential for selection.

Estimation of genetic parameters for body areas in Nile tilapia measured by digital image analysis

“…Heritability estimates varies from moderate to high for morphometric traits in Nile tilapia (Fernandes et al., 2015; Nguyen et al., 2007; Reis Neto et al., 2014; Rutten et al., 2005). In the referred studies, the morphometric traits evaluated (total and standard length, height and width) were measured manually using rulers.…”

“…At the harvest time, the fish were probably in a compensatory gain period, which explain the significant linear effect for the age covariate. Age is frequently considered a covariate in the estimation of genetic parameters for growth and morphometric traits in Nile tilapia (Bentsen et al., 2012; Oliveira et al., 2016; Reis Neto et al., 2014). Garcia et al.…”

General and specific combining ability in Serrasalmidae

“…In the Genetically Improved Farmed Tilapia (GIFT) breeding programme for tilapia ( Oreochromis spp. ), moderate heritability (0.28–0.31) for SL, body depth, body width and body area has been observed (Reis Neto et al., ). In the same breeding programme, low to medium heritability (0.17–0.23) has been reported for fillet yield over six generations (Thodesen et al., ).…”

Avaliação genética de tilápias-do-nilo durante cinco anos de seleção

“…2015 DOI: 10.1590/S0100-204X2015001000002 melhorados em sistemas extensivos ou semi-intensivos de produção (Ponzoni et al, 2005;Charo-Karisa et al, 2007;Rezk et al, 2009). No entanto, o grande potencial hídrico e a produção crescente de tilápias no Brasil (Anúario Brasileiro da Pesca e Aquicultura, 2014) favorecem a utilização de animais melhorados em condições de criação intensiva, para suprir a demanda comercial, assim como a utilização de objetivos de seleção voltados para as características de maior interesse comercial, como ganho de peso (Kunita et al, 2013;Yoshida et al, 2013a), peso (Reis Neto et al, 2014) e rendimento de filé Nguyen et al, 2010).…”