Reproductive Soundness and Egg Quality in Chickens Selected for Low and High Antibody Response

For 36 generations, White Leghorn chickens were selected for high (HAS) or low (LAS) antibody response to sheep red blood cells. The focus of this thesis was to investigate correlated responses in reproductive soundness and egg quality resulting from that selection. Forty-five hens and 25 roosters from each antibody line were used. In hens, commencement and intensity of lay, and egg quality, were analyzed; in both sexes, length of fertility was considered. Hens and roosters were mated to an intercross line to avoid confounding selection with sex effects. The LAS line was more reproductively sound, commencing lay at a younger age (11.67 ± 3.53 d; P < 0.001), lighter body weight (-169.46 ± 40.20 g; P < 0.001) and with greater intensity (2.68 ± 0.25%; P = 0.001) than the HAS line. Additionally, the LAS line had a greater length of fertility (hens: 2.43 ± 0.55 d; P < 0.001; roosters: 3.11 ± 0.71 d; P < 0.001). In contrast to their poorer reproductive soundness, the HAS line had superior egg quality compared to the LAS line. Egg shape index (4.12 ± 0.55; P < 0.001) and albumen height, measured in both mm (0.27 ± 0.12 mm; P < 0.001) and Haugh units (1.89 ± 0.91; P = 0.04), were superior in HAS hens. Selection for increased antibody response appeared to compromise reproductive soundness, perhaps due to limitations in available resources. However, the selection did not compromise egg quality.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Animal and Poultry Sciences

Department dc:contributor.department

Animal and Poultry Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2011

Author dc:creator

• Albrecht, Heather Nicole

Chair dc:contributor.committeechair

• Lewis, Ronald M.

Committee members dc:contributor.committeemember

• Siegel, Paul B.
• Pierson, Frank William

• Mycoplasma gallisepticum
• Egg quality
• Reproductive soundness
• Sheep red blood cells

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-08192011-145148

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/34647