Genetic improvement of Israeli blue (Jordan) tilapia,Oreochromis aureus(Steindachner), through selective breeding for harvest weight

Abstract

Genetic parameters and selection responses were obtained for harvest body weight of blue tilapia (Oreochromis aureus) from data collected over three generations in a selected population. A total of 18 194 records representing 186 sires and 201 dams were used in the analysis. Within generation heritability estimates for harvest body weight ranged from 0.18 to 0.58. When data from more than one generation were included in the analysis, heritability estimates became more stable (0.33-0.40) and it was 0.33 when all data were included in the analysis. The common full-sib effect accounted for 10% of the phenotypic variance in the full data set. Heritability for survival from stocking to harvest was estimated at 0.01 and 0.09 in actual units (fitting an animal model) and in the logit (sire model) scale respectively. The genetic correlation between harvest body weight and survival was 0.22 and not significantly different from zero. The total selection response for harvest body weight over the three generations of selection measured as the difference between least-squares means of selected and control lines was 17.7%. The corresponding figure when response was measured as the difference between mean breeding values of selected and control lines was 19.6%. The average inbreeding coefficient was 0.003 after three generations of selection. These results indicate that there are good prospects for the genetic improvement of harvest body weight in blue tilapia.

Morphometric traits as selection criteria for carcass yield and body weight in Nile tilapia (Oreochromis niloticus L.) at five ages

“…In the present study, h 2 estimates for BW (Table 4) vary from moderate to high and are in agreement with other tilapia BW studies (Rutten et al, 2005b ;Eknath et al, 2007 ;Khaw et al, 2009 ;Bentsen et al, 2012 ;Turra et al, 2012b ;Zak et al, 2014).…”

Differences in sexual size dimorphism among farmed tilapia species and strains undergoing genetic improvement for body weight

“…A detailed description of this selection program is outlined by Zak et al (2014). The strain was derived from three populations collected from commercial hatcheries or previously stocked irrigation reservoirs in Israel.…”

Parentage assignment with genomic markers: a major advance for understanding and exploiting genetic variation of quantitative traits in farmed aquatic animals

“…The second option to solve the pedigree problem is to use separate rearing of families until a size where tagging is possible, as in the Norwegian salmon breeding program, the first family-based selective breeding program in aquaculture, started in 1972 ( Gjedrem, 2010 ). This was successfully extended to major aquaculture species such as salmonids, tilapias, oyster, or shrimps ( Krishna et al, 2011 ; Thodesen et al, 2011 ; Gjedrem, 2012 ; Gjedrem et al, 2012 ; Zak et al, 2014 ). Although efficient, this method has three main drawbacks when it comes to estimating genetic parameters of traits.…”