Experimental Eimeria alabamensis infection in calves

Area of Science:

• Veterinary Parasitology
• Animal Health
• Bovine Diseases

Background:

• Coccidiosis, caused by Eimeria species, is a common parasitic disease in cattle.
• Eimeria alabamensis is a significant pathogen in young cattle, particularly those on pasture.
• Understanding the clinical impact of E. alabamensis is crucial for effective herd management.

Purpose of the Study:

• To investigate the clinical effects of Eimeria alabamensis infection in conventionally reared bull calves.
• To quantify the impact of E. alabamensis on appetite, clinical signs, growth rate, and fecal consistency.
• To establish a dose-response relationship for E. alabamensis infection.

Main Methods:

• Four groups of three 2-month-old bull calves were inoculated with varying doses of E. alabamensis oocysts.
• Clinical signs, appetite, growth rates, and fecal dry matter content were monitored.
• A control group of three uninoculated calves was used for comparison.
• Prepatent period and oocyst excretion duration were recorded.

Main Results:

• Inoculated calves exhibited prepatent periods of 6-8 days and oocyst excretion for 2-7 days.
• Ten out of twelve inoculated calves developed watery diarrhea, poor appetite, and depression.
• Clinical signs, including abdominal pain, were dose-dependent, being most severe at higher inoculation levels.
• Infected calves showed significantly reduced growth rates for at least 18 days post-inoculation.
• Compensatory growth was not observed within the 71-day study period.

Conclusions:

• Eimeria alabamensis infection causes significant clinical disease and growth retardation in young bull calves.
• Higher doses of E. alabamensis lead to more severe clinical manifestations and prolonged growth impairment.
• The economic impact of E. alabamensis may be substantial due to long-term reductions in growth performance.