Genetic Parameters from Univariate and Bivariate Analyses of Egg and Weight Traits in Japanese Quail

Abstract

Fully pedigreed records of a Japanese quail population were analyzed for genetic parameters of egg and BW traits. A restricted maximum likelihood (REML) procedure was applied in univariate and bivariate analyses. Quantitative genetic analyses, including maternal effects, were carried out on the records of 947 male and 861 female birds (total = 1,808). The traits were analyzed with bird as a random factor to fit the additive direct effect, bird being the individual for which the trait was recorded, namely hen (dam) for egg traits and chick (progeny) for BW. Permanent environmental effects (0.29 to 0.35) on egg traits were higher than corresponding heritabilities (0.18 to 0.25). Significant maternal genetic and maternal permanent effects were measured for hatching BW. The heritabilities of weekly BW were low, and decreasing by 5 to 6 wk of age. They were 0.07, 0.18, 0.19, 0.18, 0.19, 0.13, and 0.15 from hatching to 6 wk, respectively. Strong correlations were detected between direct genetic effects for egg traits and maternal genetic effect for BW traits. Applying such detailed analyses in the study of both egg and BW traits provides procedures to specifically evaluate Japanese quail and poultry in general. The results illustrated that the maternal permanent environmental effects made larger contributions to the variability of egg traits than did direct genetic effects. This situation implies that rearing of birds, healthcare, and feeding are very important determinants of egg characteristics.

Determination of the best model for estimating heritability of economic traits and their genetic and phenotypic trends in Iranian native fowl

“…This might be due to missing maternal genetic effects in their analyses. Saatci et al (2006) found that BW 0 had the lowest direct heritability and the highest maternal heritability among performance traits in Japanese quail that is in agreement with the results of the current study.…”

“…However, Saatci et al (2006) reported that maternal effects are not important for EW in Japanese quail. The maternal genetic and environmental effects are not relevant for ASM.…”

“…Meyer (1997) suggested that including maternal effects in the analysis reduces the bias in the estimate of genetic variance. Maternal effects in birds are different from those of mammals, because any maternal effect on chicks, incubated artificially, must be the residual effect of dam reflected in egg characteristics at laying (Saatci et al 2006).…”

Single-trait bayesian analysis of some growth traits in japanese quail

“…This LW42 heritability estimate is higher than that obtained by Saatci et al (2006), who reported 0.15. In another study, Shokoohmand et al (2007) reported heritability estimates for different strains as 0.48, 0.50 and 0.72.…”

Comparison of different models to estimate genetic parameters for carcass traits in a commercial broiler line

“…It can be transitory but can also persist throughout life and be fulfilled through a great variety of biological mechanisms. Maternal effects in birds are different from those of mammals because any maternal effect on chicks, incubated artificially, must be the residual effect of dam reflected in egg characteristics at laying (Saatci et al, 2006). Willham (1980) emphasizes that knowledge of the type and relative importance of the genetic variation attributed to the maternal effect and, especially, to the type and magnitude of the genetic correlation between the direct and maternal additive effects of the traits is of high economic importance in the elaboration of breeding programs, where an evaluation of this effect is then necessary in each specific situation.…”