Broiler Growth by Week: A Controlled-House Curve in an Open-Sided Coop

Day 35, Ross 308 AP: 2,360 grams. That is what Aviagen publishes for an as-hatched bird, with 3,268 grams of feed eaten to get there and a cumulative feed conversion of 1.386 (Ross 308 AP Broiler: Performance Objectives, 2022). Totoong numero iyan, galing sa totoong dokumento, and it still will not describe ang manok mo.

Not because the brochure is dishonest. That row was written for a house where somebody chooses the temperature, samantalang ang mga manok mo are in a kulungan where the temperature is whatever the hapon delivers. Ang agwat between those two situations is the whole subject here.

What follows is the published week-by-week table for both major strains, the one Philippine survey that exists to hold it against, and a weighing routine that builds you a curve for your own bakuran. Iyon ang punto. Everything before it is hiram lang.

Kung nagdedesisyon ka pa whether to place a batch at all, start with raising broilers in the Philippines and come back here once ang mga sisiw are on the ground.

What the two tables actually publish

Aviagen prints Ross 308 AP from day 1. Cobb-Vantress prints Cobb500 body weight from hatch, but the first day carrying weight, cumulative intake and cumulative FCR together is day 7, so that is where any comparison can honestly start.

Three footnotes decide what these numbers mean, and skipping them is how keepers end up comparing figures that were never comparable. Aviagen states that body weight is on-farm body weight, meaning feed is present in the intestinal tract. Feed intake is per living bird. And the FCR column includes the chick’s weight at placement and does not account for mortality (Aviagen 2022). Cobb-Vantress carries the same mortality footnote (Cobb500 Performance & Nutrition Supplement, 2022).

So the FCR sa mga table na ito is not sacks fed divided by kilos sold. Ang bilang mo at the end of a batch includes feed eaten by every sisiw na namatay in week two, at wala iyon sa table. Mas pangit ang lalabas na numero mo, and it is not because the birds underperformed.

As-hatched, metric, transcribed day by day from Aviagen (2022) and Cobb-Vantress (2022). These are performance objectives for controlled housing, not Philippine measurements.

One thing to notice bago ka bumaba pa sa table na iyan. Datuin et al. (2022) record a Philippine target liveweight of 1.6 to 1.7 kg against an international target of 2.1 to 2.5 kg (PJVAS 48(1):57-69). Kung para sa lokal na palengke ang alaga mo, day 28 is your row. Day 42 belongs to somebody else’s country.

Ross and Cobb disagree, and averaging them is worse than picking the wrong one

On day 35 the two tables differ by 161 grams of bird and 367 grams of feed. Cobb500 runs heavier and hungrier than Ross 308 AP from the second week onward, and it eats more from day one. Hindi iyan measurement noise between two attempts at the same thing. Dalawang magkaibang manok iyan, bred by two different companies, each published against its own objective.

Most Philippine growth charts you will find online quietly split the difference, or print one table and label it “broiler”. Both moves produce a number that no source stands behind. The midpoint of two honest figures is not a third honest figure, and that holds whether the two are growth tables or brooder temperature schedules.

Kaya itanong mo sa hatchery kung anong strain ang binibili mo, and get it on the receipt with the DOC count. Kung hindi nila masabi, or if the answer is “mixed”, use both columns as a bracket and expect to land somewhere between them. A bracket you can defend beats a point estimate you cannot.

Bakit hindi ito nangyayari sa bakuran?

Here is the closest Philippine figure in the archive, and the first thing to say about it is that nobody measured it. Datuin et al. (2022) surveyed 55 commercial broiler operations, 48 contract growers and 7 integrators, and asked them what they were aiming at. The answers sit in Table 5 on page 66, under the heading “Broiler production performance targets of growers based on type of housing” (PJVAS 48(1):57-69).

Table 5, p. 66 of Datuin et al. (2022). Read its title before its cells: it splits growers, so the 7 integrators are out and the denominator is 48, not 55. Sixteen of them are open-sided, and that is the two rows a bakuran keeper reads. Every cell is a target they named for themselves, and Table 6 on the same page has 33% of them meeting those targets only sometimes or not at all. Commercial contract growing, not backyard.

Ihambing mo iyan sa table sa itaas. At the 1.6 to 1.7 kg Philippine harvest weight the breed tables sit between 1.25 and 1.31: Ross reaches 1,657 g on day 28 at a cumulative 1.257, Cobb reaches 1,682 g on day 27 at 1.303. The open-sided target band starts at 1.50 and runs to 1.83, and 1.83 is the end to plan against. It is the ceiling those sixteen farms set for themselves, named inside a survey where a third of the growers admitted they miss what they set. At that top figure you are buying 1.83 kg of feed for every kilo of liveweight instead of roughly 1.26, which is 40 to 46% more feed for the same manok depending on the strain you compare against. That difference is the entire margin on a small batch. Iyan ang dahilan kung bakit ang planong hango sa brochure reads as tubo on paper at hindi kumikita sa totoong buhay.

Ngayon ang mas mahirap na punto, and the one this article exists to make. Datuin surveyed contract growers. Those are people running hundreds or thousands of birds, buying formulated feed by the tonne, following an integrator’s program. Nobody has published a Philippine backyard growth curve or a backyard FCR figure at all. Not PCAARRD, not UPLB, not CLSU, not DA. It is logged as gap G-1 in this site’s register of missing data.

Kaya kahit ang 1.50 to 1.83 band ay hiram pa rin, from a neighbour who is not you, and what he lent you is an aim rather than a result. Plan above it.

Heat explains the gap. It is not a multiplier.

Two review papers describe the mechanism. Kpomasse et al. (2021) report that at 32 °C, weight gain falls 21% under cyclical heat stress and 36% under constant heat stress (Veterinary Medicine and Science). Teyssier et al. (2022) report that cyclic heat stress cuts feed intake by about 15%, roughly 1.5% for every degree, with no temperature range attached to that figure, while constant heat stress cuts it 25 to 45%, about 3.5% for every degree between 22 and 35 °C (Frontiers in Physiology). The range belongs to the constant figure and gets lent to the cyclic one often. A bird that eats less grows less, and a bird spending energy on panting rather than gain converts feed worse. That is the shape of it.

Neither paper is Philippine, and neither is a correction factor. It would take one line of arithmetic to multiply 2,360 g by 0.79 and publish 1,864 g as a “Philippine day 35 weight”. Do not do it, and do not trust a chart that has. The result would carry a decimal point, look measured, and be invented.

The ambient figures make the same point from the other side. PAGASA gives a Philippine mean annual temperature of 26.6 °C and a warmest month mean of 28.3 °C (Climate of the Philippines). Those are means, not the afternoon highs inside a coop with a GI roof, and the papers’ 32 °C is an experimental condition rather than a Philippine reading. Nobody has joined those two ends with Philippine data.

What the breed company does say plainly is a ceiling. In open-sided houses with no environmental control, Aviagen recommends against growing birds above 3 kg liveweight (Ross Broiler Management Handbook, 2025). Day 42 on that table is 3,086 g. The brochure is telling you, in its own document, not to chase its own bottom row.

Week one is the exception, because a brooder is the one week you do control the temperature. Get that schedule from the brooder temperature tool rather than from the growth table.

Ano ang epekto nito sa gastos?

Take one bird at 1.7 kg. At 1.50 FCR it eats 2.55 kg of feed; at 1.83 it eats 3.11 kg. Across 50 birds that is a 28 kg difference in feed, and both ends of it come from the same Philippine target band. Walang table na makakapagsabi sa iyo nang maaga kung saang dulo ka mapupunta, and the top of that band is not a ceiling.

The peso side has a hole in it that no amount of research fills. No Philippine source publishes the price of a sack of finished commercial feed by brand or tier. BAI publishes 15 feed ingredients in pesos per kilo, which is a different figure and cannot be built into a sack price. That is gap G-15, kaya ang feed cost tool ay nagtatanong sa iyo ng presyo mula sa sarili mong dealer instead of printing a default. Isulat mo ang petsa at ang pangalan ng dealer kasama nito.

Sa bentahan naman, PSA publishes two broiler farmgate series that are not interchangeable. Household sellers received ₱150.31 per kilo liveweight in June 2026; commercial establishments received ₱118.69 per kilo over the same month. The ₱31.62 gap between them is a difference in market level, not a data error, and blending them is how a feasibility study ends up with a kita line nobody can collect. There is a longer piece on those two prices kung bago sa iyo ang hati.

Pangatlong bitag ang day-old chicks. The ₱33.50 per head figure for the week of 13 July 2026 is BAI integrator and wholesale farmgate. Hindi iyan ang binabayaran ng isang backyard keeper sa dealer para sa 50 sisiw, and that retail figure is published nowhere at all.

Kapag mayroon ka nang sarili mong presyo ng sako, the batch arithmetic is worked through in the 50-bird cost breakdown and the price you need to clear is in the break-even piece.

One more constraint lands at exactly the weight you are aiming for. PNS/BAFS 262:2018 § 6.3.1, the Philippine free-range chicken standard, sets a fixed broiler building at 10 birds per m² or 17 kg per m², whichever binds first (BAFS, Department of Agriculture). Those two limits meet at 1.7 kg per bird. Below that weight your bird count is the limit; above it, floor area is, and the kulungan you sized for 50 manok is no longer sized for 50 manok. Note the standard covers free-range production. For a broiler, no Philippine body publishes a density standard for confined backyard housing at all, kaya ang free-range figures ang tanging mapagkukunan mo.

Weigh ten birds on the same day every week

This is the part that turns a borrowed table into your own data, and it costs an hour a week.

Sampung manok, huli nang pabasta-basta. Not the ten nearest the door, and definitely not the ten biggest, kasi that is how a flock looks fine on paper right up to harvest day. Timbangin mo isa-isa on a scale that reads to 10 grams, using a basin or a sack with the scale tared, and write down every one rather than only the average.

Do it on the same day of the week and at the same point in the feeding routine. Aviagen’s own footnote is why: its figures are on-farm body weight with feed present in the gut, so a bird weighed before the morning feed and the same bird weighed after are two different numbers. Pick one habit and keep it for the whole batch.

Apat na bagay ang isulat mo kada linggo: the date, the age in days, the average, and the spread between your lightest and heaviest bird. Kasinghalaga ng average ang spread. Ten birds averaging 1.6 kg with a 400 g range is a different flock from ten averaging 1.6 kg within 80 g, and only one of those is going to grade well.

Then compare as a percentage of the objective rather than in grams. If your day-21 average is 88% of the Ross day-21 figure and your day-28 average is 79% of it, the problem started before you noticed the weights, and the likely suspects are feed access, water, or heat during the week between. A single week’s number tells you almost nothing. Four weeks of the same measurement tells you where your bakuran actually sits, which is more than any published table can do for you.

Three batches of that and you own something nobody in the country has published.

The curve nobody has published

The most useful table in this article does not exist yet. There is a European curve for controlled housing, a Philippine survey of commercial contract growers, and two review papers explaining why the two disagree. Between them is a hole exactly the shape of every reader of this page: a smallhold flock in an open-sided coop, on whatever feed the dealer had, in whatever weather the month brought.

This site can put a weight under three birds, and what each label says about where its number came from is the argument here rather than the sizes. The broiler stands at the 1.7 kg target on day 35, marked PH target, because that is what growers said they were aiming at and not a weight anybody recorded; Aviagen’s figure for the same bird on the same day is 2,360 g. The native bird beside it is marked Bohol, measured at 736 g on day 120, and it is the only measurement in the picture. The layer is marked Hy-Line, cage at day 139, the day she starts paying in itlog, and she is drawn as a dashed outline at no scale with no ₱/day under her, because nobody has published what a spent Philippine hen weighs. Every peso under a bird is that month’s PSA household farmgate times the weight above it. The broiler is worth ₱255.53 at its own June 2026 farmgate, which is ₱7.30 of liveweight for each of the 35 days it takes up space; the native bird is ₱164.82 at the native series, or ₱1.37 a day across 120 of them. The layer carries ₱6.74 an itlog and no peso-a-day line at all. Four series, one month, kasi iyon lang ang frame na magkakatabi ang tatlo.

One measured bird out of three, and that one measurement stops at day 120 because the table it was lifted from stops there.

How far below the breed table does a 20-bird backyard batch actually land at day 28? Nobody knows. Is the answer even a single number, or does it split by region, by roof material, by dry season and wet? Nobody knows that either, and until somebody weighs enough birds in enough bakuran to say, every growth chart written for Philippine keepers is either an imported target or a guess with a decimal point on it.

One line of that table can be acted on today without weighing anything, and it is already on this page. Day 42 reads 3,086 g. In the same company’s handbook, an open-sided house with no environmental control is where Aviagen recommends against growing birds above 3 kg liveweight at all. Ang huling hilera ng brochure ay isang bigat na hindi ipinapayo ng brochure mismo sa kulungang bukas ang gilid.

So the end of your batch is set by your bubong and not by the bottom of the table, and the missing Philippine curve, whenever somebody finally measures it, stops short of that line too. A keeper reading the last row as a goal has taken for a target the one row its own author advises against.

Questions people actually ask

How much should a broiler weigh at 4 weeks in the Philippines?

The breed tables put an as-hatched Ross 308 AP at 1,657 g and a Cobb500 at 1,783 g on day 28, both in controlled housing (Aviagen 2022; Cobb-Vantress 2022). No Philippine source publishes a measured day-28 weight for a backyard flock, so treat the table as a target and weigh your own birds.

What FCR should I expect in an open-sided coop? Show the answer

The one Philippine number available is not an outcome. Datuin et al. (2022) asked 55 commercial farms what they were aiming at, and split the 48 contract growers among them by housing type. The open-sided targets in Table 5 are the answers of the 16 growers in that housing: 1.50 to 1.83 for big birds and 1.50 to 2.00 for lechon manok. A third of the growers told the same survey they meet their targets only sometimes or not at all, so plan at the top of the band rather than the bottom. Contract growers and integrators either way, and not one backyard keeper among them.

Is Ross 308 or Cobb500 better for Philippine conditions? Show the answer

No Philippine trial has been published comparing the two, so there is no local answer. Cobb500 is heavier and hungrier than Ross 308 AP at the same age in the published objectives. Use the strain you actually placed.

How many birds should I weigh each week? Show the answer

Ten, caught at random, on the same day of the week and at the same point in the feeding routine. Aviagen defines its figures as on-farm body weight with feed in the gut, so a bird weighed before the morning feed and one weighed after are not the same measurement.