Feed phases: pre-starter, starter, finisher
The bird’s requirement changes every week; the bag does not. Phase feeding is how you stop overpaying for protein at the end and underfeeding it at the start.
A day-old chick and a 35-day broiler are, nutritionally, two different animals. The chick needs a very dense, very digestible, high-protein feed and eats almost none of it. The finishing bird needs energy more than protein and eats enormous quantities.
Phase feeding exists because feeding either ration to the other bird is expensive — in different directions.
The phases
| Phase | Roughly | What it is for | | --- | --- | --- | | Pre-starter | Day 0–10 | Highest protein, most digestible, usually crumble | | Starter | ~Day 11–21 | Frame and muscle development | | Grower / Finisher | ~Day 22 to sale | Energy-led; protein comes down | | Withdrawal | Last few days | No medication; clears residues before sale |
The day boundaries vary by strain, by mill and by target weight. The shape does not: protein starts high and falls, energy starts lower and rises.
Why the front end is worth the money
Pre-starter is the most expensive feed per tonne and the smallest quantity you will buy. A broiler eats only a small fraction of its lifetime feed in the first ten days.
That makes it the cheapest place on the farm to spend money well. Early growth is compounding — a chick that hits day-7 weight has a frame, a gut and an immune system that the rest of the cycle builds on. A chick that misses it does not catch up, and the shortfall is still visible at sale.
Buying cheap pre-starter to save a few thousand rupees on a flock is one of the most reliably bad decisions available.
Why chick quality shows up in day-7 weight →
Why the back end is where the cost is
The reverse is also true. Most of the feed a broiler eats, it eats in the last two weeks. Feeding an expensive high-protein ration through the finisher phase is paying a premium on the largest tonnage, for nutrients the bird no longer needs in that ratio.
This is also why the finisher phase is where withdrawal periods bite. Anything medicated at day 30 is closest to slaughter.
Antibiotic use and withdrawal periods →
Changing phase without a setback
Feed changes are a stress event. A flock that goes off feed for a day at each transition has lost three days over a cycle.
- Transition gradually where you can — mix the old and new feed over two or three days rather than switching in one morning.
- Do not change phase during another stress — a heat wave, a vaccination day, a move. Stack stresses and you get an enteric upset.
- Watch the litter after a change. A feed change that produces wet droppings is telling you something.
Form matters as much as formula
Pre-starter and starter are usually crumble, finisher usually pellet. A young chick cannot physically handle a large pellet, and an older bird eating mash sorts the grain and leaves the fines — which is where the premix and the amino acids are.
Excessive fines in a pellet bag are a real quality problem and a real cost.
Layers are a different sequence
Broiler phases run down in protein. Layer phases run through rearing — starter, grower, developer — and then switch to a lay ration whose defining feature is calcium, stepped up again as the flock ages and shell quality declines.
Never put a rearing pullet on a layer ration early. The calcium level that a laying hen needs damages the kidneys of a bird that is not yet laying.
The honest caveat
The phase specifications published by Ross, Cobb and Hubbard are breeder targets, and Pakistani commercial rations have repeatedly tested below them on crude protein. Use the manual as a reference point for the shape of the programme, and your own weekly weights and FCR as the test of whether the feed in front of you is delivering.