Quantifying calf mortality on dairy farms: Challenges and solutions

Area of Science:

• Veterinary Epidemiology
• Animal Health Monitoring
• Agricultural Science

Background:

• Calf mortality is a key indicator in Dutch dairy herds, but varying calculation methods cause confusion.
• Discrepancies in definitions hinder effective monitoring and understanding among stakeholders.

Purpose of the Study:

• To scientifically evaluate and compare various calf mortality definitions.
• To determine the most valid, useful, and comprehensible parameters for policymakers and farmers.
• To establish standardized indicators for monitoring calf mortality in Dutch dairy herds.

Main Methods:

• Consultation with experts to identify 10 different calf mortality definitions.
• Evaluation of definitions based on age categories, time periods, and denominators.
• Assessment of scientific validity, policy usefulness, and farmer comprehensibility.

Main Results:

• Different definitions significantly impact calculated mortality rates; the original rate was 16.5% annually.
• Subdivided age categories (perinatal, postnatal, preweaned, weaned) yielded lower, distinct rates (e.g., 3.3%, 4.5%, 3.1%).
• Four key parameters were selected for their balance of scientific value, monitoring utility, and clarity.

Conclusions:

• Standardized definitions are crucial for accurate calf mortality monitoring.
• Selected parameters (perinatal, postnatal, preweaned, weaned calf mortality) improve understanding and stakeholder agreement.
• Clear health indicators are essential for effective animal health management in dairy farming.