Validated quantitative trait loci for eggshell quality in experimental and commercial laying hens

Tuiskula-Haavisto, Maria; Honkatukia, Mervi; Dunn, Ian; Bain, M.; Koning, Dirk-Jan de; Preisinger, Rudolf; Schmutz, M.; Arango, Jesus; Fischer, Daniel; Vilkki, Johanna

doi:10.1111/age.12671

Cited by 7 publications

(1 citation statement)

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“…Although the estimate of heritability for cuticle deposition was high for all breeds, differences in estimates of heritability between breeds should be considered with caution given the differences in the instrumentations used within this study, the dates of the measurements, and the hens’ environments and ages. Our attempts to identify non-genetic factors involved in the variation of the cuticle suggest that stressors [15] and fixed environmental factors, such as hatch or house, have significant effects in this and other studies [28].…”

Section: Discussionmentioning

confidence: 91%

Genetic variation and potential for genetic improvement of cuticle deposition on chicken eggs

Dunn¹,

Woolliams²,

Wilson³

et al. 2019

Genet Sel Evol

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Background The cuticle is an invisible glycosylated protein layer that covers the outside of the eggshell and forms a barrier to the transmission of microorganisms. Cuticle-specific staining and in situ absorbance measurements have been used to quantify cuticle deposition in several pure breeds of chicken. For brown eggs, a pre-stain and a post-stain absorbance measurement is required to correct for intrinsic absorption by the natural pigment. For white eggs, a post-stain absorbance measurement alone is sufficient to estimate cuticle deposition. The objective of the research was to estimate genetic parameters and provide data to promote adoption of the technique to increase cuticle deposition and reduce vertical transmission of microorganisms. Results For all pure breeds examined here, i.e. Rhode Island Red, two White Leghorns, White Rock and a broiler breed, the estimate of heritability for cuticle deposition from a meta-analysis was moderately high (0.38 ± 0.04). In the Rhode Island Red breed, the estimate of the genetic correlation between measurements recorded at early and late times during the egg-laying period was ~ 1. There was no negative genetic correlation between cuticle deposition and production traits. Estimates of the genetic correlation of cuticle deposition with shell color ranged from negative values or 0 in brown-egg layers to positive values in white- or tinted-egg layers. Using the intrinsic fluorescence of tryptophan in the cuticle proteins to quantify the amount of cuticle deposition failed because of complex quenching processes. Tryptophan fluorescence intensity at 330 nm was moderately heritable, but there was no evidence of a non-zero genetic correlation with cuticle deposition. This was complicated furthermore by a negative genetic correlation of fluorescence with color in brown eggs, due to the quenching of tryptophan fluorescence by energy transfer to protoporphyrin pigment. We also confirmed that removal of the cuticle increased reflection of ultraviolet wavelengths from the egg. Conclusions These results provide additional evidence for the need to incorporate cuticle deposition into breeding programs of egg- and meat-type birds in order to reduce vertical and horizontal transmission of potentially pathogenic organisms and to help improve biosecurity in poultry. Electronic supplementary material The online version of this article (10.1186/s12711-019-0467-5) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 91%