Brooder Temperature for Chicks: What Works in Philippine Ambient

Ilang degrees ba dapat ang brooder, and when does the lamp come off? The grid below answers the first at every reading a Philippine brooder plausibly sits at. Take that reading inside the box at chick level, hindi sa labas ng bahay at hindi sa weather app, then read across to the week your batch is in. The second question is where the two documents stop agreeing.

Read off the brooder tool, which prints both schedules in full alongside the Philippine native-chick band and averages none of the three into another. Merck below is the MSD Veterinary Manual; MSU is Mississippi State University Extension.

Week 1 is the only week outdoor ambient falls short everywhere

PAGASA puts the warmest month in the Philippines at a mean of 28.3 °C (Climate of the Philippines). Merck’s week-1 floor is 29.4 °C and MSU’s week-1 target is a single 32.2 °C. Both sit above the hottest month this country records outdoors, so a reading below 29.4 °C at the chicks means a day-old chick needs heat added, and outdoor air here is always below it. Ang sukat sa loob ng kahon ang susundin, hindi ang buwan at hindi ang lalawigan. The exception runs the other way and the coop pillar already carries it: on a dry-season afternoon a week-one chick in a closed box can pass the 32.2 °C ceiling on ambient alone, with nothing switched on. The 34 °C row of the grid above is that case, and nothing on it calls for a lamp in any week.

Which is an argument about where the thermometer hangs. Here is that kahon in section:

The heat lamp is at the top and the cone under it is the heat, widest where it reaches the litter. The wire guard stands outside that cone rather than under it, its job being to keep sisiw near the lamp, not to hold warmth in, and the feed and water straddle the cone’s edge so a chick can eat without walking off the warm floor. The chicks are evenly spread, which is what Aviagen puts against “correct” in its brooder distribution figure, not a convenience of the drawing. All of those you can check by looking.

The thermometer is the one thing you cannot, which is why it is the only coloured line in the picture. It runs from lamp height down between two chicks and stops level with their bodies: the 29.4 to 32.2 °C week-1 target is a floor temperature, taken where a day-old chick’s tiyan actually sits. A reading from up at the lamp is a different number, and nothing on this page measures how different, so the drawing puts no figure on it. The last label is the Philippine correction, PH air alone can pass it: Science Garden’s April mean daily maximum is 34.6 °C in the 1991 to 2020 normals, above the 32.2 °C ceiling both schedules share, on an average Quezon City afternoon, nothing switched on.

The shape of the two week-1 figures decides most of what follows. Merck publishes a band, 29.4 to 32.2 °C, and lowers it 2.8 °C a week (MSD Veterinary Manual). A band tolerates a reading. MSU publishes one figure for day-old, 32.2 °C, and a step of 5 to 7 °F a week (Grow Healthy Chicks), and a point tolerates nothing. The pillar prints both schedules week by week; the rows quoted below are only the ones the adjudication needs.

The only disagreement worth acting on is a week-1 reading of 30 °C

Take week 2 at a reading of 28 °C. Merck’s band for that week runs 26.6 to 29.4 °C (MSD Veterinary Manual), so you are inside it and you add nothing at all. MSU’s band for the same week is 28.3 to 29.4 °C (Grow Healthy Chicks), so you are below it and you switch the lamp on. Two published authorities, one thermometer, opposite instructions.

That 28.3 °C is worth a second look, because it is not MSU’s number in MSU’s own units. Walang extension service sa Mississippi ang sumukat ng panahon natin, kaya hindi ito magkasundong sukat kundi magkatabing bilang lamang. MSU publishes 90 °F at day-old and a weekly reduction of 5 to 7 °F; the 28.3 is this site’s interpolation of that step converted to Celsius, 90 °F less 7 °F being 83 °F. PAGASA’s warmest month, quoted at 28.3 °C, is 82.94 °F. The two agree to one decimal place in Celsius and nowhere at all in the units their own sources published.

The other two contradictions sit in week 1, at 30 °C and at 32 °C. Both readings are inside Merck’s 29.4 to 32.2 °C band and below MSU’s single 32.2 °C target, so Merck leaves the lamp off and MSU switches it on. Those are readings a Philippine brooder produces rather than hypotheticals, for the reason above: a closed box in the dry season runs above the air outside it. The grid holds two cells of that kind, and one more of a different shape at week 2, where both documents publish a band and 28 °C falls inside one of them and below the other.

The subtractions below are this page’s rather than either document’s, and the three are nowhere near the same size.

By week 4 no Philippine month is cold enough for either schedule

Merck’s week-4 band tops out at 23.8 °C (MSD Veterinary Manual). PAGASA’s coolest month averages 25.5 °C (Climate of the Philippines), which is above that ceiling and not by a hair. There is no month in the national mean where that row calls for a lamp. That is a mean and not a daily low, national and not local, so a highland station in the cool months is the standing exception. MSU has the heat off from week 4 onward and never meets the problem.

Merck nonetheless prescribes heat through weeks 4 and 5 and turns it off in week 6, on day 35. MSU reaches its final 21.1 °C target at the end of week 3, on day 21. That is 14 days apart on when the lamp goes off, and every one of those 14 days falls in a stretch where Philippine ambient already exceeds the target being heated toward. Kuryenteng nasasayang ang mga araw na iyon, at dagdag na init sa kahong mainit na.

The coop pillar already puts the general shape of this: from week 3 the Philippine question is when the heat comes off, not how to add more. What the rows above add is the date. Neither document has a line for it.

Of the 36 ambient-by-week cells the brooder tool renders, 26 read too warm on both schedules, which is 72.2%, and only 5 of them, 13.9%, call for added heat on both. Two more say you are inside both bands, and the remaining three are the contradictions above. The six room temperatures and the six weeks are this site’s own grid, picked to bracket Philippine conditions, so that denominator is a design decision here and not a published statistic.

The Philippine band is a 2010 textbook figure, and it does not step down

Both schedules on this page are temperate documents, written for housing whose ambient the keeper sets. The Philippine figure a keeper meets alongside them, 31 °C ± 1 °C for native chicks, is not a third measurement, and this page said otherwise until 16 August 2026. Pediongco and Simbulan (2025) print it at Pampanga State Agricultural University as “the ambient temperature requirement for brooding”, footnoted to their reference [4], which is A. L. Lambio in Poultry Production in the Tropics (2010), a UPLB text. What that trial measured was its own nine treatment means, running 30.42 to 32.58 °C, plus huddling below 31 °C and above 75% relative humidity. The pillar retracted the same attribution on 15 August 2026 and works through what survives it.

Set the band against the shape of the two imported schedules and the difference is structural. Merck and MSU both step down every week. The textbook band does not step down at all, and the trial quoting it held one band across weeks 1 to 4 without testing whether a day-old and a four-week-old want the same air. Lambio’s book may carry a step-down somewhere the paper does not reproduce. I have not read the 2010 edition.

Neither Merck nor MSU carries a humidity term anywhere in its brooding schedule. Kaya ang tanging linyang mababasa ng isang tagapag-alaga tungkol sa halumigmig ay ang isang obserbasyong iyon mula sa Pampanga, at hindi sapat ang isang obserbasyon.

Size the kahon for week 6, not for the tray that arrives

Total brooder floor for the whole batch, m², off the brooder tool. The per-chick figures behind these totals are Penn State Extension small-flock figures from the United States, converted from square feet, and the pillar prints them per bird.

Fifty chicks take about 1.16 m² in week 1 and about 4.64 m² in week 6, roughly four times the floor. Ang kahong sakto lang sa dumating na tray ay mas mahal ayusin sa week 4 kaysa gawing malaki sa araw na ginawa mo, at hindi rin naman lumalaki ang bakuran.

No heat-lamp wattage appears anywhere here, and not because the number has never been printed. Mississippi State prints one, for a single enclosure: a cardboard box that “will brood up to twenty-five chicks”, heated by “a 60-watt incandescent light bulb” (Grow Healthy Chicks). That is a bulb sized to one box in Mississippi, not a rate you multiply by fifty sisiw sa bakuran, and the scalable version is the thing no veterinary manual, breed company or standard publishes, because the answer moves with the enclosure and the air around it. The pillar divides that bulb out per chick and says what does and does not carry over. Floor space after the brooder is a separate standard with separate arithmetic, and what the Philippine standard allows per square metre works through it for the flock the sisiw turn into.

One Philippine table exists, and it is a regional leaflet that disagrees with itself

Neither the Department of Agriculture nor the Bureau of Animal Industry publishes a brooding schedule as a national standard. What exists is one regional extension leaflet. DA Regional Field Office II prints a four-row table in Tips on Poultry Raising and introduces it as temperatures “found to be ideal for brooding under Philippine conditions”, then immediately adds “Use this as a guide only”: 32.2 to 35.0 °C at 0 to 1 week, 29.4 to 32.2 °C at 1 to 2, 26.7 to 29.4 °C at 2 to 4, and “Remove the supply of heat” above 4 weeks (DA RFO II, Tips on Poultry Raising, read 22 August 2026).

Read the two columns against each other before following it. The third row steps the Celsius band down to 26.7 to 29.4 °C and leaves the Fahrenheit column at 85-90 F, which is the row above; 26.7 to 29.4 °C is 80 to 85 °F. A keeper can follow one column or the other, not both, and only the Celsius one steps. So the Philippine answer is a guide-only leaflet from one region carrying an internal contradiction, which is why this page still spends its length adjudicating between an American veterinary manual and an American extension service. A second extension service publishes one too, hotter than both in week 1 and stepping toward a 16.7 to 18.3 °C building temperature no Philippine month comes near (Penn State Extension, and the pillar prints it in full). Neither the grid above nor the tool carries it: a schedule whose tail has you heating a building already warmer than its target is not one a keeper here can follow. The two that are left disagree by two weeks, and the adjudicating falls to keepers reading foreign PDFs rather than to anyone whose job it is.

The second gap is older than it looks. There is one Philippine brooding trial I can find, four weeks, native chicks, and it never set out to test a temperature band at all: it took 31 °C ± 1 °C from a 2010 textbook and varied heat sources and litter underneath it. No commercial broiler arm, no second site, no week 5. So a 2010 band was carried into a 2025 paper with nothing in between that tried to check it, at hindi ko masasabi kung iisang bilang nga ba ang bagay sa sisiw sa unang linggo at sa isang buwang gulang.

Questions people actually ask

What temperature should day old chicks be kept at?

The MSD Veterinary Manual gives a brooder floor temperature of 29.4 to 32.2 °C for day-old chicks and steps it down 2.8 °C a week until it reaches 21.1 °C. Mississippi State University Extension gives a single 32.2 °C at day-old and steps down 5 to 7 °F a week. The two are not the same document and should not be averaged together. Both of those week-1 figures sit above 28.3 °C, which is the mean of the warmest month in the Philippines according to PAGASA, so outdoor air anywhere in the country is below the week-1 target at any time of year. A third figure, 31 °C plus or minus 1 °C, circulates for Philippine native chicks. It is a textbook band out of UPLB, from A. L. Lambio in Poultry Production in the Tropics (2010), and the 2025 Pampanga State Agricultural University brooding trial that made it well known cites it as the requirement it worked inside rather than a result it measured.

When can I turn the brooder heat lamp off? Show the answer

The MSD Veterinary Manual runs brooder heat through week 5 and turns it off in week 6, on day 35. Mississippi State University Extension reaches its final 21.1 °C target at the end of week 3, on day 21, and says heat is not usually needed after that. In the Philippines the answer sits at or before the earlier of the two, because PAGASA puts the coolest month at a national mean of 25.5 °C, which is already above the 21.1 to 23.8 °C band the MSD schedule wants a four-week-old chick held in. That is a national mean rather than a local daily low, so a highland station in the cool months is the standing exception.

Do chicks need a heat lamp in a hot country? Show the answer

In the first week, almost always. The lowest week-1 target either published schedule gives is 29.4 °C, and the warmest month in the Philippines averages 28.3 °C by PAGASA measurement, so outdoor air on its own never reaches it. What decides the lamp is the reading taken at chick level inside the brooder rather than the outdoor figure: a closed box on a dry-season afternoon can sit well above the air around it, and a brooder already reading above 32.2 °C at the chicks needs heat taken out rather than added. After the first week the question reverses. By week 4 the coolest Philippine month, at a 25.5 °C mean, is already warmer than the target both schedules are stepping down toward.

How much floor space does a brooder need for 50 chicks? Show the answer

About 1.16 m² in week 1 and about 4.64 m² by week 6, roughly four times the starting area. Those totals come from Penn State Extension small-flock figures of 0.25 ft² per chick in week 1 rising to 1.0 ft² by week 6, converted to square metres. They are United States figures rather than Philippine ones. A 2025 Philippine study on native chicks at Pampanga State Agricultural University built its pens to a floor-space requirement of not less than 0.30 ft² per bird, which lands between the Penn State week-1 and week-2 rows.