The terms used across the rest of the site, defined in one sentence each. Where there is a formula, the formula is given. Where the industry works with a reference range, the range is given — with the caveat that a range is not a target: the target is something each company declares.
The unit of work#
Flock is a group of birds of the same age and origin, managed as a single production unit. It is the central object of the whole system: projection, decision and audit all happen per flock.
Cycle is the full period from placement to catch, plus the downtime that follows. In broiler grow-out that is roughly 42 days of bird plus the downtime days.
Placement is the arrival of day-old chicks in the house. It is day zero for the flock.
Staggered placement means deliberately offsetting placements across houses or sites so that birds reach the plant continuously rather than all at once.
Downtime is the gap between one flock leaving and the next arriving, spent on cleaning and disinfection. Its purpose is to break the pathogen cycle: shortening it hands a health problem to the next flock, which pays for something it did not cause.
The physical space#
House is the structure the birds live in. In this system the hierarchy is zone, site and house.
Site is the group of houses within one farm or zone. It is the health unit: what enters a site affects every house in it.
Stocking density is birds — or kilos — per square metre of house. It is regulated on welfare grounds and it drives performance: past a certain point, each additional bird reduces the weight of all of them.
Flock indicators#
Feed conversion ratio is kilos of feed consumed per kilo of live weight gained. Lower is better. Feed is the largest cost item in a grow-out flock, so this is the indicator that moves the most money.
Cumulative mortality is the percentage of birds that have died since placement. It does not include birds that left alive in a thinning, and confusing the two is the most common and most expensive misreading there is: it turns any staggered catch into an apparent catastrophe.
Thinning is the partial removal of a flock before the final catch. The birds leave alive, walking, on their way to the plant. It is done when the plant asks for different sizes or when projected density would exceed the permitted maximum.
Uniformity is the percentage of birds within ±10% of the flock's average weight. It measures how even the flock is, and two flocks with the same average weight and different uniformity are worth different amounts at the plant.
Daily weight gain is the grams a bird puts on per day. It is the most direct way to see whether a flock is ahead or behind for its age.
EPEF — European Production Efficiency Factor — is the composite indicator that sums a flock up in one number. It is calculated as:
EPEF = (survival % × live weight in kg × 100) ÷ (feed conversion × age in days)
The age that goes into that formula is the age on the day the bird leaves the house, not the date the plant processes it. There is usually a day between the two, sometimes two days, and since EPEF divides by age, that extra day costs around nine points over a 39-day cycle.
Links in the chain#
Breeder is the parent bird that produces the fertile egg the grow-out chick comes from.
Hatchery is the process that turns a fertile egg into a day-old chick. It takes about 21 days and happens in a dedicated plant.
Processing is the slaughter and processing of the bird. It happens at the plant, normally the day after the bird left the house.
How the business is organised#
Integrator is the company that controls the whole chain — chick, feed, farms and plant — and supplies the grower with the inputs to raise the birds.
Contract grower is the party that provides the house, the labour and the utilities, and receives chicks and feed from the integrator. They do not decide the catch day or the price: they receive a settlement calculated on a scale that is not theirs.
Independent grower buys their own chicks and their own feed and sells their own birds. They carry all the cost and all the risk, and feed is their largest item.
Grower settlement is the document that closes a flock and triggers payment. It arrives after the flock has gone, so it says what happened at the end but not on which day the gap opened.
System terms#
Confidence band is the range within which the system expects a projected value to fall. In this system no projection is published without its band: a bare number, with no range, hides how much whoever gave it actually knows.
Hard constraint is something management declared non-negotiable — a withdrawal period, a plant quota, a maximum density. It has no weight and no tolerance: it filters. The moment it had a tolerance, it would stop being hard.
Policy is everything management declares once: what to optimise for, what can never be violated, who wins when two things clash, and how much the system decides alone. A live policy is not edited: it is duplicated to a draft, simulated and activated as a new version.
Industry reference ranges#
The figures used as sector benchmarks for broilers in Colombia: mortality below 5%, feed conversion below 1.72, EPEF above 320.
A sector benchmark is not your company's plan. It is useful for placing yourself against the rest, not for judging whether a flock met its target: that is measured against the target your operation declared, which may be tighter or looser for perfectly good reasons.