Maternal protection against Ascaridia galli?

Area of Science:

• Veterinary Parasitology
• Immunology
• Poultry Science

Background:

• Maternally derived antibodies can confer passive immunity in young animals.
• Ascaridia galli is a significant gastrointestinal nematode parasite of poultry worldwide.
• The role of maternal immunity in protecting chicks against Ascaridia galli has not been fully elucidated.

Purpose of the Study:

• To determine if maternal antibodies influence chick resistance to Ascaridia galli infection.
• To investigate the correlation between maternal antibody levels and antibody transfer to egg yolk.
• To assess the impact of infection dose and chick sex on worm burden.

Main Methods:

• One-day-old chicks from nematode-infected or uninfected hens were experimentally infected with Ascaridia galli at two dose levels.
• Worm burdens were quantified at six weeks post-infection.
• A. galli-specific antibody concentrations were measured in dam plasma and egg yolk.

Main Results:

• A high correlation was observed between maternal antibody levels and antibody concentrations in egg yolk.
• No significant difference in worm burdens was found between chicks from infected and uninfected dams, indicating no protective maternal immunity.
• Chicks exposed to a higher infection dose exhibited significantly higher worm burdens.
• Female chicks infected with a lower dose harbored longer and heavier female worms compared to males.

Conclusions:

• Maternal immunity does not provide protection against Ascaridia galli infection in chicks.
• Antibody transfer from dam to egg yolk occurs but does not confer resistance to this nematode.
• Infection dose is a critical factor in determining worm burden, with a potential sex-specific effect on parasite development.