Genetic improvement of fanned tilapias: estimation of heritability of body and carcass traits of nile tilapia (Oreochromis niloticus)
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- 作者：Velasco ; Ravelina R. ; Janagap ; Carmela C. ; de-Vera ; Marietta P. ; Afan ; Lilibeth B. ; Reyes ; Ruben A. ; et. al.
- 刊名：Aquaculture
- 出版年：1995
- 出版时间：December 1, 1995
- 年：1995
- 卷：137
- 期：1-4
- 页码：280-281
- 全文大小：107 K
文摘
This study compared the locally farmed strains of Oreochromis niloticus with a genetically improved strain (the G1FT strain) for differences in carcass traits. A nested design was followed (one sire mated with two dams) to produce a total of 40 full-sib families. Thirty individuals (3-59) from each family were individually tagged with fingerling Floy tags and reared communally for 124 days in a 600 m earthen pond. One hundred and twenty individuals from other test strains (Israel (Is), Thailand (Th) and Egypt (Eg)) were stocked in the same pond. At harvest, the mean body weight and dressed weight of the different genetic groups were not significantly different (P < 0.01). For estimating heritability (h2), the various carcass traits was first corrected for initial age and size differences. The estimated h2 based on the sire component of variance for males and females, respectively, were as follows: body weight (0.61, 0.24); body depth (0.61, 0.57); standard length (0.48, 0.44); dressed weight (0.63, 0.40); gutted weight (0.66, 0.33), head weight (0.17, 0.48) and fillet weight (0.63, 0.30). The genetic correlation between weight at harvest and dressed weight was 0.80. These results indicate good prospects for selection for various carcass traits. However, inclusion of these traits as separate performance traits in a selection program may not be necessary because of high genetic correlation among them.