Circulating prolactin concentrations in chickens infected with Eimeria tenella

Area of Science:

• Veterinary Parasitology
• Avian Physiology
• Animal Immunology

Background:

• Coccidiosis, caused by Eimeria tenella, is a significant poultry disease.
• Understanding the physiological impact of coccidiosis is crucial for effective disease management.
• Previous studies have indicated metabolic disturbances during parasitic infections.

Purpose of the Study:

• To investigate the effects of Eimeria tenella infection on circulating glucose, prolactin, electrolytes, and haematocrit in cockerels.
• To elucidate the relationship between physiological changes and prolactin concentration during coccidiosis.
• To identify key biomarkers indicative of Eimeria tenella infection.

Main Methods:

• Three-week-old cockerels were inoculated with 50,000 Eimeria tenella oocysts.
• Blood samples were collected at various time points post-infection.
• Concentrations of glucose, prolactin, sodium, and potassium were measured.
• Haematocrit levels were determined to assess red blood cell volume.

Main Results:

• A reduction in haematocrit and an increase in glucose were observed by day 5 post-infection.
• Elevated prolactin concentrations were detected in infected birds from day 7 onwards compared to controls.
• Plasma electrolyte levels (sodium and potassium) remained unchanged throughout the study.
• The observed changes in prolactin correlated with water loss and osmotic shifts.

Conclusions:

• Eimeria tenella infection significantly impacts glucose and haematocrit levels in cockerels.
• Elevated prolactin is a key physiological response to coccidiosis, likely mediated by osmotic changes.
• Maintaining hydration and managing water balance may be critical in mitigating prolactin alterations during infection.