Longitudinal genetic analyses of fillet traits in Nile tilapia Oreochromis niloticus

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

“…results at 119 and 231 days of age (0.56 and 0.40, respectively), similar results have been previously reported (Turra et al, 2012a). These results indicate that selection for BW could lead to an indirect positive impact in the genetic gain for CY.…”

“…Many authors studying the genetic parameters of BW in tilapia obtained significant estimates for that effect ( Rutten et al, 2005b ;Eknath et al, 2007 ;Khaw et al, 2009 ;Bentsen et al, 2012 ;Turra et al, 2012b) and note the importance of including the family effect in BW analysis. However, other experiments studying morphometric traits and CY (Rutten et al, 2005a ;Turra et al, 2012a) did not show strong evidence for including the family effect in analyses. In the present study, evidence of the importance of the inclusion of family effect appears at the first two ages and then decreases at the following ages.…”

“…Even so, only a few studies have been conducted to estimate the genetic parameters of these slaughter traits for fish and these have mostly focused on fillet traits (weight and yield) (Kause et al, 2011(Kause et al, , 2007Nguyen et al, 2010 ;Rutten et al, 2005aRutten et al, , 2004Thodesen et al, 2012 ;Turra et al, 2012a). These authors, however, have described difficulty in acquiring fillets with minimal processing errors because there is no consensus about filleting method and fillet contents.…”

“…We measured body weight (BW), standard length (SL) (a measure from the inferior maxillary extremity to the end of caudal peduncle), head length (HL) (a measure from the inferior maxillary to the end of the operculum), corrected length (CL) (a function of SL and HL (CL=SL-HL)), height (H) and width (W). These morphometric traits were chosen because they are easily measured longitudinal traits and normally present moderate to high h 2 (Rutten et al, 2004 ;Turra et al, 2012a). The method for H and W measurement was influenced by results from Diodatti (2006) and was performed on a perpendicular line starting at the anus.…”

“…These authors, however, have described difficulty in acquiring fillets with minimal processing errors because there is no consensus about filleting method and fillet contents. Turra et al (2012a) estimate that there is a high genetic correlation between carcass yield (CY) and fillet yield (FY). Because CY is more easily acquired and can be obtained with less processing errors, using CY instead of FY as a selection objective is likely to be a useful option.…”