Growth Curve And Estimation Of Genetic Parameters Of Parameters In Jing Wu Quality Duck

To study the growth characteristics of Jingwu quality duck, the nonlinear curves of Gompertz model,Logistic model,Von Bertalanffy model were used to fit the growth model, and heritabilities and genetic and phenotypic correlations of body weights between growth curve parameters were obtained for the first and the second generation using the multivariate mixed models procedure.The results were as followed:1. The growth curves were appropriately fitted with all three models, but the Gompertz model fit the growth in 1-5 weeks better for the first and the second generation, the Logistic model fit the growth in 6-10 weeks better for the first generation. And the Gompertz model fit the growth in 6-10 weeks better for the second generation. Hybrid changes the later period growth from the Logistic model for the first generation into the Gompertz model for the second generation.2. The second generation had a higher A, a lower B and a smaller ti comparing with the first generation. The six parameters of three models for male were consistent with for female. The effect of cross altered the trajectories of growth and leading to prematurity for the second generation.3. The body weights had high heritability from 0.54 to 0.82. In this study, the heritability estimates for body weight in 1,2,5,7 and 9 weeks were higher and lower in 3, 4,6,8 and 10 week. The results showed that the heritability for body weight changed in interval in Jingwu duck.4. The high genetic correlations and phenotypic correlations were observed among body weight in adjoining weeks, except that 0.13 and 0.14 in 7 week and 8 week, and 0.15 and 0.14 in 9 week and 10 week, respectively. The phenotypic correlations for body weights were consistent with the genetic correlation. The genetic correlation increase with week, slowly rise in 6 week, and then slowly decline in 7 week, sharply decline in 8 week and 9 week, rise in 10 week.5. The heritability estimates for mature body weight, the weight at maximum rate of growth and the largest weekly body weight gain were high. The heritability estimates for weekly body weight were higher than the mature body weight. The age at maximum rate of growth and B had moderately heritability and K had low heritability.6. The mature body weight, the weight at maximum rate of growth and the largest weekly body weight gain of Gompertz model,Logistic model,Von Bertalanffy model the lowest genetic correlations with the body weight in 1 week, the highest with the body weight in 10 week. The K and the age at maximum rate of growth of Gompertz model and Logistic model and the B and the age at maximum rate of growth of Von Bertalanffy model had negative genetic correlations with weekly body weight, in addition between the age at maximum rate of growth and the body weight in 10 week. A negative correlation increased and then decrease with age.