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Nielsen H.M.,432 as | Odegard J.,432 as | Olesen I.,432 as | Gjerde B.,432 as | And 3 more authors.
Aquaculture | Year: 2010

The aim of this study was to estimate genetic parameters and heterosis for weight, length and survival traits for common carp measured at different time periods at commercial farm conditions. A diallel cross between two land race strains (Duna and Amur), and two farmed strains (Tata and Szarvas 15) was used. Five females and 10 males per strain were used to produce six families for each of the 16 cross combinations resulting in 96 families each with 20 fish. The fish were weighed at tagging (W0), and also their length were measured at first autumn (W1, L1), second spring (W2, L2), and second autumn (W3, L3). Survival was defined as survival from second spring (W2) to second autumn (W3). Heritabilities for weight and length traits were estimated using univariate models, whereas genetic correlations and heritabilities for survival were estimated using multivariate models. The difference between the strains with respect to survival was clearly significant with Duna having the highest expected survival rate (81%), followed by Amur (69%), Tata (53%) and Szarvas 15 (51%). The level of heterosis (cross vs. purebred) varied from - 14 to 29% for weight traits, from 1.7 to 8.3% for length traits, and from 8-37% for pond survival. Heritabilities were low for early weight and length traits (W0, W1, W2, L1, and L2, 0.11-0.16) but high for W3 and L3 (0.49, 0.50). For survival the heritability on the underlying scale was 0.34 ± 0.09 corresponding to a heritability of ∼ 0.2 on the observable scale. High genetic correlations (0.81-0.98) were estimated between weight and length measured at the same time (W2/L2, and W3/ L3) and between weight measured in the first autumn (W1) and second spring (W2). Genetic correlations between weight and survival were low and non-significant for W2 (0.06 ± 0.35), but high and significant for W3 (0.65 ± 0.15). The high levels of heritabilities for length and weight at harvest (W3) and the moderate heritability for survival indicate that selective breeding for these traits could be successful in common carp. © 2010 Elsevier B.V. All rights reserved.

Odegard J.,Nofima Marin | Olesen I.,Nofima Marin | Dixon P.,CEFAS - Center for Environment, Fisheries and Aquaculture Science | Jeney Z.,Research Institute of Fisheries Aquaculture and Irrigation | And 7 more authors.
Aquaculture | Year: 2010

Estimates of strain effects, heritabilities and genetic correlations for pond survival, resistance to Aeromonas hydrophila and resistance to koi herpesvirus (KHV) were obtained from a diallel cross of 92 full-sib families of common carp produced from four strains (Szarvas 15, Tata, Duna and Amur) and using five females and ten males per strain. Disease resistance was obtained from survival data from challenge-tests using intraperitoneal injection for A. hydrophila and cohabitation for KHV. Two separate challenge-tests were conducted for each disease. The overall survival rates were 44% and 34% for the two tests of A. hydrophila, and 7% and 5% for the two tests of KHV. Pond survival (averaging 78%) was observed over a six months period prior to harvest (at approximately 18 months of age). The three traits were analysed jointly in a multivariate threshold model. For KHV the strain Szarvas 15 had the lowest observed (purebred) survival (0%) followed by Amur (11%), Duna (12%) and Tata (21%), while for A. hydrophila, the lowest (purebred) survival was observed for Duna (28%) followed by Amur (31%), Szarvas 15 (38%) and Tata (48%). Heterosis was not significant for KHV and A. hydrophila resistance, although highly significant for pond survival. The estimated heritability (on the underlying liability scale) was low (0.04 ± 0.03) for A. hydrophila resistance, very high (0.79 ± 0.15) for KHV resistance, and moderate (0.34 ± 0.09) for pond survival. The genetic correlation between the two challenge-tested diseases (KHV and A. hydrophila) was moderately high (0.61 ± 0.29), although uncertain, while the estimated genetic correlations between pond survival and the two challenge-tested diseases were low and not significantly different from zero (0.01 ± 0.28 and - 0.22 ± 0.21 for A. hydrophila and KHV, respectively). The latter may be expected for KHV, as no outbreaks of the disease had been observed in Hungary. Based on the favourable heritabilities of KHV and pond survival there is good prospect for joint improvement of these two traits in common carps through genetic selection. © 2010 Elsevier B.V. All rights reserved.

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