What do FCR, EPEF, stocking density and other farm terms mean?
Definitions of the most important indicators and terms in poultry farming — written clearly, without jargon. Useful for farmers, workers and anyone starting out on a farm.
verifiedFrom the team that has organised work on poultry farms for years.
Why this glossary?
Poultry farming has its own language: production indicators, veterinary regulations, record-keeping systems. We have gathered here the definitions that most often come up in daily farm work — from FCR and EPEF to IRZplus and KSeF.
Each term is explained in one or two sentences. If you want to dig deeper, see the related guides or the sources listed at the bottom of the page.
Poultry glossary
FCR — Feed Conversion Ratio
How many kilograms of feed are used per kilogram of live weight gain. The lower the FCR, the better the feeding efficiency; a good result for broilers is around 1.6–1.8.
EPEF — European Production Efficiency Factor
A composite index combining survival rate, daily weight gain, rearing time and FCR into a single number. A higher EPEF means a better cycle result; values above 350–400 are considered very good.
EWW — European Efficiency Factor
Europäischer Wirtschaftlichkeitsfaktor — used interchangeably with EPEF in some countries and by some integrators. Calculated using the same logic: survival × daily weight / (time × FCR) × 100.
ADG — Average Daily Gain
The increase in a bird's live weight per day of rearing, expressed in grams. It is calculated by dividing the total flock weight gain by the number of birds and the number of days.
Stocking density (kg/m²)
The maximum live weight of birds placed per square metre of poultry house floor. Polish and EU regulations limit stocking density to 33 kg/m² (standard) or up to 42 kg/m² when additional welfare requirements are met.
Withdrawal period
The time that must pass after the last administration of a veterinary medicine before the animal or its products (meat, eggs) can safely enter the food chain. The withdrawal period is stated on every veterinary medicine leaflet.
Biosecurity
A set of organisational and sanitary measures designed to protect a farm from the introduction and spread of infectious diseases. It includes controlling who enters the farm, disinfection, isolating visitors and proper disposal of dead birds.
Broiler
A chicken raised solely for meat production, reared for 35–42 days to a slaughter weight of 2–2.5 kg. Broilers are characterised by intensive growth rates and an efficient FCR.
Laying hen
A hen kept for the production of table or hatching eggs. The production cycle typically lasts 52–72 weeks; housing systems include cages, aviaries or free range.
Placement (of birds)
The moment day-old chicks or young birds are placed in the poultry house, starting a new production cycle. The placement date is the starting point for flock records, withdrawal period calculations and collection planning.
Flock / production cycle
One complete rearing cycle — from placement of chicks to the birds leaving the house (loading for slaughter or culling). After each cycle the house is washed, disinfected and left empty for the required rest period.
Mortality / losses
The number or percentage of birds that died during the production cycle from natural or disease causes. Cumulative mortality of 2–4% is considered normal for broilers; higher values indicate a health or management problem.
Flock uniformity
A measure of how evenly matched the birds are in weight, expressed as the percentage of individuals within ±10% of the average weight. High uniformity (above 80%) makes feed management easier and leads to better slaughter results.
Footpad dermatitis (FPD)
Inflammatory lesions on the footpads of birds, caused mainly by wet and contaminated litter. The FPD score is assessed by slaughterhouses and affects flock welfare ratings and retail audit results.
HPAI — Highly Pathogenic Avian Influenza (bird flu)
A notifiable viral disease with very high mortality in poultry. Confirmation of an outbreak leads to immediate culling of the flock and the imposition of restriction zones.
ND — Newcastle Disease
A highly contagious viral disease caused by avian paramyxovirus. Like HPAI it is notifiable and may lead to flock elimination and restrictions on bird movements.
IRZplus
The Integrated Animal Register — the ARMA system used in Poland for recording poultry flocks. Farmers are required to report placements, slaughters, losses and stocking changes within the deadlines set by law. The portal itself can be awkward, so in DlaFerm.pl you can — if you want — have these reports sent to IRZplus automatically, without logging into the ARMA portal.
KSeF — National e-Invoice System
The Polish Ministry of Finance platform for issuing, sending and storing structured electronic invoices. From 2026 the KSeF obligation covers further categories of businesses, including those providing services to farms.
Litter
The material covering the poultry house floor — most commonly wood shavings, straw or wood chips. Litter quality and moisture directly affect footpad health (FPD), bird comfort and production results.
Inter-cycle break (downtime)
The period between one flock leaving the house and the next placement, used for washing, disinfection and litter renewal. The minimum break length is usually required by the integrator or welfare regulations.
Frequently asked questions about poultry terms
What is FCR and how is it calculated?add
FCR (Feed Conversion Ratio) is the total feed consumed divided by the total weight gain of the flock. Example: if a flock of 10,000 birds consumed 35,000 kg of feed and gained 20,000 kg in total, the FCR is 1.75. A lower result means better efficiency.
What is the difference between EPEF and FCR?add
FCR measures feeding efficiency only. EPEF combines several indicators at once: survival rate, daily gain, cycle length and FCR. It therefore gives a broader picture of the whole cycle, not just feed use.
What is the permitted stocking density for broilers in Poland?add
The standard limit is 33 kg of live weight per square metre. With additional welfare requirements in place (including welfare indicator monitoring) approval can be obtained for up to 39 or 42 kg/m².
What happens if I fail to register my flock in IRZplus?add
Missing registration deadlines in IRZplus can result in the loss of direct payments or sanctions from ARMA. The registration obligation arises from the Animal Identification and Registration Act. To make deadlines easier to keep, in DlaFerm.pl you can have flock-status reports sent to IRZplus automatically — you only enter the data once in the Flock Card.
Does the DlaFerm.pl app help calculate FCR and EPEF?add
Yes. Based on daily Flock Card entries (feed, weight, mortality) the app automatically calculates FCR and EPEF for each cycle and displays trend charts.
Sources & resources
- linkNational Poultry Council — Chamber of Commerce (KRD-IG)
- linkNational Research Institute of Animal Production (IZ-PIB) — feeding standards and housing technology
- linkChief Veterinary Inspectorate (GIW) — regulations and welfare requirements
- linkARMA — IRZplus poultry flock registration
- linkPolish Ministry of Finance — National e-Invoice System (KSeF)
A term missing from the glossary?
Write to us — we will answer and add the missing definition.
Phone
+48 796 258 151