Genetic correlations between the maternal genetic effect on chick weight and the direct genetic effects on egg composition traits in a White Leghorn line

Abstract

Selection can be a useful way to alter yolk proportion and thereby egg dry matter which, owing to its economic importance, is a trait of substantial importance for the egg-processing industry. However, the egg is primarily the chamber of embryonic development. The main purpose of this study was to estimate genetic correlations between the maternal effect on chick weight at hatching and the direct effect on different egg composition traits, in particular, yolk proportion. Additionally, genetic parameters were estimated for egg composition traits. To create a data set suitable for estimation of genetic parameters, a three-round selection experiment was set up. Birds were selected based on their predicted breeding values for the genetic maternal effect on chick weight and the direct genetic effect on yolk proportion according to the theory of elliptical selection. Genetic parameters were estimated using a multiple trait animal model and restricted maximum likelihood. The maternal heritability for chick weight was 0.5, whereas the direct heritability was dose to 0. The genetic correlations between the maternal effect on chick weight and the direct effect on yolk proportion, yolk weight, albumen weight, albumen dry matter concentration, and egg weight were 0.14, 0.76, 0.93, 0.14, and 0.99, respectively. The heritabilities for yolk proportion, yolk weight, albumen weight, albumen dry matter concentration, and egg weight were 0.33, 0.43, 0.57, 0.38, and 0.60, respectively. We conclude that breeding ought to be a useful way to increase egg dry matter with no expected unfavorable correlated effects on chick weight.

Egg shell quality in Japanese quail: characteristics, heritabilities and genetic and phenotypic relationships

“…As shown in Table 2, the heritability estimate of EW found in our study of 0.81 was fairly high, and the 2.5% to 97.5% BCI was narrow (0.74 to 0.90). Similar to our findings, many researchers have reported high heritability estimates for EW in Japanese quails (Minvielle, 1998;Sezer, 2007;Lotfi et al, 2012) and in chickens (Hartmann et al, 2003;Dunn et al, 2005;Zhang et al, 2005;Wolc et al, 2010). Heritability estimate for SG was found to be high (0.41, Table 2).…”

“…Several reports are published estimating the heritabilities and genetic correlations for various egg quality traits, particularly for chicken hens (Grunder et al, 1989;Hartmann et al, 2003;Zhang et al, 2005), but few studies have been conducted to examine the genetic variability of egg shell quality characteristics in Japanese quail (Sezer, 2007;Lotfi et al, 2012). Therefore, the objective of the present study was to estimate heritabilities and genetic correlations for egg shell characteristics in Japanese quail utilizing the multivariate animal model using the Bayesian approach via Gibbs sampling.…”

Determination of Phenotypic Correlations Between Internal and External Quality Traits of Guinea Fowl Eggs

“…The major constituent of albumen is water amounting to 88% of total weight. The most important trait of egg composition, linked to egg dry matter, is the yolk/ albumen ratio [7][8][9] . Beside the yolk/albumen ratio, eggshell resistance to shocks is an economically primordial trait as it determines the ability of eggs to withstand transportation from producers to consumers [10] .…”

Phenotypic characterization of chicken inbred lines that differ extremely in growth, body composition and egg production traits

“…Heritability values for body weight and growth traits are high, estimated between 0.21 and 0.68 (LE BIHAN-DUVAL et al 2001, ZHANG et al 2003, GAYA et al 2006, KAMALI et al 2007. Heritability values of 0.42-0.52, 0.31-0.69, and 0.28-0.6 were reported for age at first egg, egg number and egg weight, respectively, in different outbred chickens (WEI and VAN DER WERF 1995, HARTMANN et al 2003, BUITENHUIS et al 2004, WOLC et al 2007, LWELAMIRA et al 2009.…”