At a glance. Check house preparation, floor and air conditions, humidity, feed and drinking access during a broiler flock's first week after placement.
The first seven days set the ceiling on everything that follows. In week one a chick spends about 80% of its energy on growth and only 20% on maintenance, its temperature-regulation system is not yet working, and its appetite and gut are being programmed for life. A modern broiler chick should roughly quadruple its weight in the first 7 days - from about 40 g at placement to around 180 g. Miss that, and no amount of good management later fully recovers it. Brooding is not a formality before the "real" grow-out; it is the most important week you will manage. This guide covers the temperature curve, humidity, and the checks that tell you whether it is working.
Why temperature comes first
A day-old chick cannot hold its own body temperature - it depends entirely on the house. Too cold and the chick huddles, stops eating, and burns yolk reserves it needed for growth; too hot and it pants, dehydrates and stops eating just the same. Either way the result is the same: a light, uneven, disease-prone flock. Getting brooding temperature right, and adjusting it correctly as chicks grow, is the single highest-return thing you do in week one.
The week-by-week temperature curve
Start warm and come down gradually. A workable curve, measured at chick level:
- Day 1-3: 33-35 C at the chicks (about 32-34 C under the brooder canopy)
- Then drop about 3 C per week, taking the upper end of the range early in each week
- By 6 weeks: 18-21 C, the comfortable grow-out temperature
Two operating rules make the curve safe. Reduce by no more than about 0.5 C per day so the change is gradual, and when nights are cold or the weather turns, raise the night temperature by about 2 C to hold the chicks comfortable in the dark. Sudden drops chill the flock; slow, planned reductions do not.
Read the chicks, not just the thermometer
The thermometer tells you the air; the chicks tell you the truth. Their distribution under the heat source is the most reliable thermometer you have:
- Huddled together under the heat, chirping loudly: too cold - raise the temperature
- Pushed to the edges, away from the heat, panting with wings spread: too hot - lower it
- All to one side: a draft is blowing across them - find and stop it
- Spread out evenly, active, quiet, eating and drinking: temperature is right
Walk the house and look at the chicks several times a day in week one. They will show you a problem before any gauge does.
Measure at chick level, and mind Celsius vs Fahrenheit
Air temperature at head height is not what the chick feels on the litter. Measure at chick level - on the floor, where the birds actually are. Be careful reading mixed sources, too: many guides quote floor or brooder temperatures in Fahrenheit (a first-week target of about 90-95 F, easing to 70-75 F later), which converts to the 32-35 C down to 21-24 C range above. Pick one scale and label whether you mean air, floor or chick-level temperature so nobody on the farm is working to the wrong number.
Humidity: the forgotten half of brooding
Temperature gets all the attention; humidity quietly decides whether the chicks stay hydrated. Dry brooding air pulls moisture out of tiny chicks fast. A workable relative-humidity (RH) ladder:
- Day 0-7: 65-70% RH
- Day 8-10: 60-65%
- Day 15-28: 55-60%
- After day 28: hold around 55%
The danger line is 50%. If first-week RH drops below 50%, chicks dehydrate and simply cannot hit that 4x weight gain by day 7. Remember, too, that higher humidity makes a given temperature feel warmer to the chick - so when you raise humidity, ease the air temperature down a touch to match. Later in the flock, keeping RH in the 50-70% band also helps suppress dust and ammonia.
The 7-day weight target
Weigh a sample at 7 days - it is the earliest hard number that predicts final performance. The target is about 4.25 times placement weight (roughly 180 g from a 40 g chick). Flocks that hit their 7-day weight go on to better final weight, better feed conversion and lower total mortality, because the early gut and immune development that produced that weight keeps paying off. A light 7-day weight is an early warning to check temperature, feed access and chick quality now, while you can still act.
Crop fill: the 24-hour check
Weight takes seven days; crop fill tells you within hours whether chicks have found feed and water. Gently feel the crop of a sample of chicks:
- 2 hours after placement: at least 75% of chicks should have full crops
- By 8 hours: at least 85% with feed and water in the crop
- Next morning: about 95% should have full crops
The texture matters as much as the count. A soft, pliable crop means the chick ate feed and drank water - perfect. A hard crop means it found feed but not enough water. A swollen, watery crop means it drank but has not eaten. Crop checks in the first day let you fix a feed or water access problem before it costs you the 7-day weight.
Feed and water in the first days
Open water within an hour of placement, at about 16-24 C - not icy. Many farms give lightly sweetened water (around 1-1.5% glucose) or add about 5% glucose plus a little vitamin C for the first three days to counter transport stress, then switch to clean fresh water. Offer feed about three hours after water, once chicks have emptied the yolk and are hungry, and feed little and often - about 8 times a day for the first three days, easing to 7. Run 24 hours of light on placement day so no chick fails to find feed and water in the dark. Water must not be delayed past 24 hours after hatch, or dehydration sets in.
Common first-week mistakes
- Starting too cold, or dropping temperature too fast - chilled chicks stop eating and never catch up
- Measuring air temperature at head height instead of at chick level
- Ignoring humidity - dry air below 50% RH dehydrates chicks and caps the 7-day weight
- Not reading chick behavior - the gauge says fine while huddled chicks say otherwise
- Skipping crop-fill and 7-day weight checks - you lose your two earliest warning signals
- Too few feeder and drinker points - chicks must not have to travel far in week one
Brooding is cheap to do well and expensive to do badly. Nail the temperature curve, hold the humidity, watch the chicks and check crop fill and 7-day weight, and you set the flock up for the feed conversion and final weight that make or break the batch. Tell us your house type and climate and we will help you spec brooding heating, ventilation and the layout that makes a strong first week easy to hit.
Visual checklist
Related reading
Day-Old Chick Placement: First Feed and Water Access
Poultry Brooding Temperature: Air, Floor and Bird Checks
Further reading
Use the management guide for the actual breed, age and housing system when selecting flock targets. Review changes with the farm team and the relevant nutrition, health or equipment specialist.
