Short answer: the right brooding temperature for day-old chicks is about 30°C at chick height in whole-house brooding. Start day-old broiler chicks there and bring the shed down slowly, by about 1°C every few days, to about 20°C by day 27. Then watch the chicks to confirm it. At Vital Feeds (Private) Limited, many “slow flock” calls we get trace back to a cold first week, not to the feed.
A day-old chick cannot keep itself warm yet. If the shed is cold, the chick spends its energy staying warm instead of growing, and it eats and drinks less. That lost start shows up in the final weight and in feed conversion (FCR).
What is the right brooding temperature by age?
These are whole-house air temperatures based on the Aviagen Ross Broiler Management Handbook 2025, rounded and shown by age. (The 2025 edition sets the steps by body weight, from 30°C at 44 g to 20°C above about 1.5 kg. The ages below come from the earlier, age-based edition and fit a flock growing on target.) Measure at chick height, not at your head height.
| Age (days) | Air temperature (°C) |
|---|---|
| 0 | about 30 |
| 3 | about 28 |
| 6 | about 27 |
| 9 | about 26 |
| 12 | about 25 |
| 15 | about 24 |
| 18 | about 23 |
| 21 | about 22 |
| 24 | about 21 |
| 27 | about 20 |
With spot brooders (gas or coal heaters with guards), the area under the heater is warmer and the edges are cooler. At placement, the Ross handbook gives about 32°C at the brooder edge and about 29°C two metres away. That is fine: chicks move to the spot they like. What matters is that they have the choice. The handbook also says that after 27 days the shed can stay at about 20°C, adjusted to how the birds behave.
How warm should the floor and litter be?
Chicks sit on the litter, so a cold floor chills them even when the air feels warm. Aviagen gives these targets before the chicks arrive:
- Floor: 28 to 30°C before the litter is spread.
- Litter: 28 to 32°C, spread evenly 2 to 4 cm deep.
- Pre-heating: temperature and humidity steady for at least 24 hours before placement, and longer in cold weather or a poorly insulated shed.
No floor thermometer? Put a hand flat on the litter: it should feel warm, not cool. For cold nights in December and January, see our guide on how to keep broilers warm in winter.
What humidity do chicks need during brooding?
Temperature alone does not tell the full story. The Ross handbook bases its chart on 60 to 70% relative humidity for the first 3 days and about 50% after that. Dry air makes chicks lose water and feel colder at the same thermometer reading; damp air makes the shed feel hotter. Gas and coal heaters add moisture to the air, so a shed with spot brooders and little fresh air can become too damp. A cheap digital thermometer that also shows humidity is worth hanging at chick height.
How do I read the chicks?
- Too cold: chicks crowd tightly under the heater and make loud, distressed calls.
- Too hot: chicks pant with open beaks, spread their wings and move to the walls, away from the heat.
- Draught: chicks bunch on one side of the brooder, away from the cold air.
- Just right: chicks spread evenly, some eating, some drinking, some resting, with a soft, steady sound.
Check them at night as well as in the day. Punjab nights in winter can drop far below the afternoon temperature. Aviagen also uses the chick’s own body heat as a check: vent temperature should be 39.4 to 40.5°C in the first days, read with a small digital thermometer and judged together with behaviour.
How do I know chicks found feed and water?
Warm chicks eat and drink; cold ones do not. Put feed on paper or chick trays and fill drinkers before the chicks arrive, so every chick finds both within minutes. Water should be about 18 to 21°C, and the brooding area well lit (Aviagen gives 30 to 40 lux for whole-house brooding, 80 to 100 lux under spot brooders). Then feel the crops of a sample of chicks. A full crop is soft and rounded. The Ross 2025 targets are:
| Time after placement | Chicks with a full crop |
|---|---|
| 2 hours | at least 75% |
| 4 hours | at least 80% |
| 8 hours | more than 80% |
| 12 hours | more than 85% |
| 24 hours | more than 95% |
If many crops are empty, check temperature, light and drinker height first. Our broiler water guide shows what to expect from week 1.
Does the shed need ventilation in winter?
Yes. Closing every curtain to save heat builds up ammonia and moisture from gas or coal heaters. The Ross handbook asks for a minimum ventilation rate from the start to remove waste gases and bring in fresh air, while keeping air speed at floor level for young chicks below 0.15 metres per second, so there is no draught. Give a small amount of air often, rather than none at all. Wet litter is a sign the shed needs more air.
How do I check that brooding went well?
Weigh a sample of chicks at placement and again at day 7. Aviagen says the 7-day weight should be at least 4.5 times the day-old weight. If your chicks fall short, look back at the first three days: temperature, floor warmth, crop fill and water. Compare later weeks with the broiler weight chart.
What brooding mistakes cost the most?
- Lighting heaters only when the chicks arrive, so the floor is still cold.
- Reading a thermometer hung at head height instead of chick height.
- Dropping the temperature in big steps to save fuel in week 2.
- Sealing the shed completely and letting ammonia and moisture build up.
- Skipping the crop check, so a poor start is found only at day 7.
- Blaming the starter feed for a slow first week before checking the shed.
Written by Waqas Rafiq, CEO, Vital Feeds (Private) Limited.
A warm first week lets a good starter feed do its job. See our broiler starter, grower and finisher feed, or message the mill on WhatsApp (UAN 0311 1555136).