Work Package 7 - Product Safety

Rationale: The inhabitants of the EU produce and consume 6.5 million tonnes of eggs per annum. They are accepted across cultures and are a high quality source of protein. However, eggs are also a potential medium for the growth of pathogenic organisms, most notably Salmonellae.

The egg offers several defences against the growth and entry of micro-organisms, including the presence of a shell and cuticle which prevents the entry of micro-organisms and the bactericidal and bacteriostatic proteins of the shell, membranes and albumen. Measurements of eggshell quality currently used by breeders may not adequately characterise an egg which resists the entry of pathogenic organisms, either intrinsically because of the shell structure or because it is less likely to crack. The objective is to develop genomic approaches to enhance eggshell quality by selection and improve safety and reduce waste by utilising measurements that will improve resistance to structural failure and bacterial penetration [1].

This Work Package combined novel physical measures (ease of bacterial translocation, crystal microtexture) and detailed ultra-structural studies to identify gene and genomic region variants suitable for use in selection using the latest numerical techniques. Using F2 and half-sib populations which have already been established allows the detection of QTL. The efforts have been supported by expression studies of the shell gland from the same lines to identify candidate gene and gene pathways. This will finally be extended to identify genes differentially expressed in animals segregating for identified QTL.

Objectives for WP7 at start of SABRE

• To fine map eggshell quality QTL
• To detect QTL in a commercial pedigree populations 
• To identify candidate genes for QTL through expression analysis

Results: Please see the results section on the right side of this page.

WP Leader: Dr Ian Dunn (Roslin Institute)

Partners involved:

• The Roslin Institute and R(D)SVS, University of Edinburgh
• University of Glasgow
• MTT Agrifood Research Finland
• Institute National de la Recherche Agronomique
• Lohmann Tierzucht