Zhejiang South Tailake Freshwater Fish Breeding Co Ltd.

Huzhou, China

Zhejiang South Tailake Freshwater Fish Breeding Co Ltd.

Huzhou, China
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Luan S.,Chinese Academy of Fishery Sciences | Yang G.,Zhejiang Institute of Freshwater Fisheries | Yang G.,Zhejiang South Tailake Freshwater Fish Breeding Co. | Wang J.,Zhejiang Institute of Freshwater Fisheries | And 8 more authors.
Aquaculture | Year: 2012

Genetic parameters and response to selection were estimated for harvest body weight of the giant freshwater prawn Macrobrachium rosenbergii using a fully pedigreed synthetic population from three introduced strains. The data included 65,917 progeny that were from 331 sires and 544 dams in five generations with a nested mating structure. Harvest body weight was transformed by square root for analysis. Variance components and genetic parameters were estimated using an animal model and the restricted maximum likelihood method. The estimated breeding values of all animals over five generations were calculated using best linear unbiased prediction. Within generations, the heritability estimates for harvest body weight in each generation ranged from low to moderate (0.055±0.012 to 0.223±0.045) and were significantly different from zero (P<0.05). Only the common environmental effect of the three generations from G 1 to G 3 could be estimated, which was found to vary from 0.024±0.012 to 0.032±0.014. Across generations, the heritability and common environmental effect estimates were low (0.056±0.014 and 0.039±0.005, respectively) and significantly different from zero (P<0.05). Heritability of harvest body weight in females was significantly higher than that in males across populations. However, the genetic correlation of harvest body weight between sexes across population was close to unity (0.942±0.070), indicating that body weight in male and female shrimp is most likely controlled by the same genes. The response to selection in harvest body weight was estimated by two methods (the realised and predicted responses). The realised response was estimated from the difference in the least squares means of body weight for the selection and control populations, while the predicted response was obtained from the difference in the mean breeding values between generations. The back-transformed realised response was 26.22%, while the predicted responses estimated using two set of genetic parameters obtained from within- and across-generations datasets were 18.06% and 12.38% in actual units, respectively, after performing four selections. The results are discussed in relation to selection work with other farmed shrimps, and solutions for increasing and disseminating genetic gain are outlined. © 2012 Elsevier B.V.


Luan S.,Chinese Academy of Fishery Sciences | Wang J.,Zhejiang Institute of Freshwater Fisheries | Wang J.,Zhejiang South Tailake Freshwater Fish Breeding Co Ltd. | Yang G.,Zhejiang Institute of Freshwater Fisheries | And 8 more authors.
Aquaculture Research | Year: 2015

Genetic parameters were estimated for survival of Macrobrachium rosenbergii using a fully pedigreed synthetic population formed by three introduced strains. The data included 107 398 progeny from 394 sires and 654 dams in six generations with a nested mating structure. The variance components and genetic parameters were estimated using a generalized linear mixed model with the probit link function. Available heritabilities in survival from the generation G3 to G5 ranged from 0.007 ± 0.020 to 0.066 ± 0.044 (P > 0.05) using a model that included the common environmental effect (c). Across generations, low heritability (0.016 ± 0.012, P > 0.05) was estimated using the model with inclusion of the c effect. There were statistically significant differences in the heritability estimates between different ponds for most generations. Moreover, the genetic correlation of survival between ponds over six generations varied from low to high (-0.0007 ± 0.17 to 0.80 ± 0.069) and was significantly different from unity. There were low correlation coefficients (-0.039 ± 0.096 to 0.342 ± 0.081) between body weight estimated breeding value (EBV) and survival EBV of families in different generations. The low heritabilities for survival are most likely caused by low genetic variation in the founder populations and reduced genetic variation because of consecutive selection. © 2013 John Wiley & Sons Ltd.


Luan S.,Chinese Academy of Fishery Sciences | Yang G.,Zhejiang Institute of Freshwater Fisheries | Yang G.,Zhejiang South Tailake Freshwater Fish Breeding Co. | Wang J.,Zhejiang Institute of Freshwater Fisheries | And 8 more authors.
Aquaculture International | Year: 2014

A selective breeding program was established to improve the growth and survival of the cultured giant freshwater prawn Macrobrachium rosenbergii. The response to selection was estimated for the survival of M. rosenbergii using a fully pedigreed synthetic population formed by three introduced strains. The data included 122,761 progeny from 437 sires and 723 dams in seven generations with a nested mating structure. The genetic parameters and estimated breeding values (EBVs) were estimated using a generalized linear mixed model with the probit link function. The realized response was estimated from the difference in the marginal means of survival for the selection and control populations, while the predicted response was obtained from the difference in the mean retransformed survival rate based on the survival EBVs between generations. The realized genetic gain in survival from the G1 to G6 generation ranged from -1.24 to 2.72 %. The accumulated realized genetic gain (5.02 %) expressed as a percentage was 8.46 %. Across the generations, high heritability (0.401 ± 0.020, Set 1) was obtained when using the model without the c effect and was significantly different from zero (P < 0.05). However, the low heritability and common environment (0.013 ± 0.011 and 0.088 ± 0.007, Set 2) were estimated using the model that included the c effect. The accumulated predicted gains (6.29 and 0.61 %, respectively) from the Set 1 and Set 2 parameters over the five generations of selection expressed as proportions were 9.08 and 0.87 %, respectively. The low genetic gain for survival is most likely caused by a low relative weight in the selection index and reduced genetic variation because of consecutive between-family selection. © 2013 Springer Science+Business Media Dordrecht.

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