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European Production Efficiency Factor (EPEF / EPEI) Calculator

Computes the standard international benchmark metric combining flock livability, market weight, cycle length, and FCR into a single index score.

Enter Parameters

%
lbs
days
Calculated Output
European Production Efficiency Factor
428.8EPEF69.2 g/day Avg Daily Gain
What This Result Means
Your calculated EPEF is 428.8 (Excellent Performance (>400)). Daily gain averaged 69.2 grams/day over 38 growout days.
Calculation Details & Practical Equivalents
EPEF / EPEI Index Score
428.8
Average Daily Gain (ADG)
69.2 g/bird/day
Livability Rate
96%
Mortality Rate
4%

Formula & Mathematical Methodology

Standard Mathematical Formula
EPEF = [Livability (%) × Average Live Weight (kg) × 100] ÷ [Age (days) × FCR]

Formula Variables Defined

LivabilityLivability Percentage(%)

Percentage of birds surviving to harvest (100% - Mortality %)

WeightAverage Live Weight(kg (or lbs))

Average weight per bird at slaughter

AgeSlaughter Age(days)

Total growout duration in days

FCRFeed Conversion Ratio

Feed consumed divided by live weight gain

Step-by-Step Calculation Example

Example: High Performance Broiler Flock

96% livability, 2.60 kg (5.73 lbs) average weight, 38 days harvest age, 1.55 FCR.

  1. Weight in kg = 5.73 lbs ÷ 2.20462 = 2.60 kg
  2. Numerator = 96 × 2.60 × 100 = 24,960
  3. Denominator = 38 × 1.55 = 58.9
  4. EPEF = 24,960 ÷ 58.9 = 423.8
Final Output: 423.8 EPEF Score

Key Assumptions

  • Average weight is converted to kilograms internally per standard international EPEF convention.

Biological Limitations

    Verified Scientific & Veterinary Sources

    Version: 1.0•Methodology Reviewed: 2026-01-20
    1. Ross 308 Broiler Performance Objectives & Nutrition Specificationsindustry-standard
    Aviagen Technical Services (2022). Aviagen Broiler Management Guide
    Access Source Authority
    2. Poultry Development Review: Production Performance Standards & Efficiency Metricsgovernment
    Food and Agriculture Organization (FAO) of the United Nations (2018). FAO Animal Production and Health Guidelines
    Access Source Authority

    European Production Efficiency Factor (EPEF / EPEI) Calculator — FAQs

    Scores over 400 represent world-class performance. Scores from 350 to 399 are solid commercial results, while scores under 300 indicate opportunities for flock improvement.

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