A Chicken Died Suddenly: BAI's Form Asks for Six Weeks of Deaths Before the First Sign

Ano ba ang hinihingi ng papel kapag may namatay?

The paper that gets opened when a Philippine backyard flock starts dying is public, and a keeper can read it before a single bird is lost. That is worth doing, because most of what it asks for is about days that have already gone by.

The paper is Annex 10 of the Avian Influenza Protection Program Manual of Procedures, 2025 edition, which the Department of Agriculture adopted through DA Memorandum Circular No. 11, Series of 2025, signed by Secretary Francisco P. Tiu Laurel Jr. on 11 April 2025. The annex is titled “MODIFIED DISEASE INVESTIGATION AND SURVEILLANCE FORM FOR AI” and it runs from printed page 119 to page 123. Every link to the manual below opens the same 210-page file at its cover, and the page numbers given here are the printed ones.

Two things about it matter before the columns. The first is the word at the top of page 119, where the header reads “FARM QUESTIONNAIRE FOR SURVEILLANCE AND DISEASE INVESTIGATION TO DETERMINE RISK FACTORS FOR AVIAN INFLUENZA”, under a blank “Questionnaire No. _____”. A questionnaire is something somebody takes you through out loud, and a spoken answer is an answer from memory unless it was written down at the time.

The second is the order the fourteen numbered sections come in. Section 2, on page 119, asks for Population and Age side by side for chicken, duck, quail, gamefowl, turkey and others, before the form asks anything about a disease. Section 9, on page 122, asks whether the farm “has a visitor’s log book and mortality records, with written biosecurity measures”, Yes or No, so a mortality record appears here as a biosecurity question with a binary answer. Section 14 is the last, Duck Management, ending on “Duration of grazing”, after which the form closes with the marker -end on page 123.

Between those two ends sits the section that opens when birds have already died. Section 4, printed on page 120 and headed “AI Detection Information”, is a table with six columns:

1. Every date on which a death was seen, and the form says so in brackets: all of the dates, not the worst one.
2. What was observed on each of those dates, meaning how many birds and what was wrong with them.
3. The age group the birds that died belonged to.
4. Whether samples were collected, where they were tested, and what the results were.
5. “Total population of that age group where mortalities were observed”, which is the form’s own wording and is a count of the living.
6. Which farm house the deaths occurred in.

Five of those six are yours. The fourth belongs to a laboratory, and a keeper who has never sent a sample writes a dash in it. That is arithmetic on the columns: the investigation that follows a dead bird is built almost entirely out of what only the person who fed her can supply. A farm that ticked No back in section 9 has already lost five of these six to memory, and the form charges no penalty for that. It carries on asking.

Why does the form spend most of its space on the birds that are still alive?

The state’s own paperwork looks at the flock and the calendar. Once you notice that, the shape of both forms makes sense.

Column five is the clearest case. “Total population of that age group where mortalities were observed” is a denominator. Three dead birds out of six is a catastrophe. Three out of forty is a bad week. Three out of four hundred is Tuesday. The number the investigation divides by is a count of living birds standing in a kulungan on the day the deaths happened.

Annex 20 of the same manual, the Case Investigation Forms of BAI, printed on pages 153 to 157, leans the same way. Its fifth section, on page 156 under the heading “ANAMNESTIC DATA”, asks for an “Estimated Population At-Risk” in three columns per species: “Within Farm”, “Within 3 km radius” and “Within 10 km radius”. All three count living birds. On page 157 the same form carries a four-cell block headed TOTAL NUMBER OF BIRDS, whose cells run from “Number of birds (dead or alive) put under restriction” to “Number of birds depopulated”. Two of the four count birds that are still breathing.

Kaya ang tala na kailangan mo ay tala ng buong grupo, at ang petsa nito ay ang araw mismo ng pangyayari. Ang kapitbahay na may tatlumpung manok sa likod-bahay ay may kasagutan doon anumang oras. Ikaw na may apat na batch ay kailangan pang tumingin.

The first checkbox on Annex 20’s first section, printed on page 153, reads “TYPE OF FARM: Backyard ____ Commercial ____”. A backyard flock is the first thing the form offers, so none of the above is written for somebody else.

How far back does the form look?

Six weeks, and it counts backwards. The sixth section of Annex 20, printed on page 156, is headed WEEKLY MORTALITY, and the note under the heading is one line long: “Nd: data concerning mortality rates recorded in the 6 weeks prior to the onset of clinical signs”. The table under it has two columns, WEEK, subdivided into FROM and TO, and NUMBER OF ANIMALS DEAD.

Six weeks backwards from a date only you can supply, and a head count from the day itself. Both forms are filled in by whoever comes out to investigate, working from what you can tell them. What a keeper supplies is the answers. Set the two forms beside each other and this is what they ask for, against whether a keeper can still answer it a week later.

Field wording from DA-BAI’s Avian Influenza Protection Program Manual of Procedures 2025, Annex 10 printed p. 120 and Annex 20 printed pp. 153 to 157. The right-hand column is my judgement and not the document’s: BAI publishes the questions and rates nobody’s memory.

The sixth row is the one that inverts what everybody assumes. The investigation wants a baseline, and a baseline is a count taken while nothing appeared to be wrong. A flock that lost a bird a week for five weeks and eleven in the sixth is a different animal from one that lost nothing for five weeks and eleven in the sixth, and the carcass in front of you tells them apart only if somebody kept the first five weeks.

The pivot for the whole table is a single date. Page 157 asks for “Date of onset of AI clinical signs” and, separately, for “Clinical signs observed by the farmer”. Every window on the form hangs off that date: the second section asks for birds moved in “(Twenty one days before the onset of the first clinical signs)” and for birds moved out in the span beginning “20 days before the onset of the first clinical signs”. Twenty-one going in and twenty going out reads as a mismatch in the printing, and both are measured from the day the keeper names.

Sa iyo lang manggagaling ang petsang iyon. Ang gabing parang may kakaiba ka nang napansin pero hinayaan mo muna. That night is the date Annex 20 § 6 counts back from. Tatlo o apat na araw ang lumilipas bago maisip ninuman na may problema, at malabo na ang alaala doon.

The carcass carries a much shorter clock than the record does, and the article on ringing the LGU vet sets out what the laboratory accepts and how quickly. The manual’s own version of that clause, at printed page 41, is one sentence: “Dead birds that are non-decomposing, properly and securely packed, may also be submitted to the laboratory.” Non-decomposing is the manual’s word for it. The reporting decision itself belongs to that article and to the disease pillar.

Does the age of the bird narrow anything down?

It narrows the class. It stops short of a name, and the veterinary literature is blunter about that than most keepers expect. I am not a veterinarian, and every clinical line here is a quotation from a reference that states its own review date.

Take the condition defined almost entirely by a pattern. MSD Veterinary Manual’s page on sudden death syndrome of broiler chickens, at Full Review July 2024, describes birds that “appear healthy and may be feeding, sparring, walking, or resting when they suddenly extend their necks, gasp or squawk, and die rapidly”. The condition “most commonly occurs in healthy, fast-growing broiler chickens, and it occurs more frequently in males”, and it “should be suspected in well-grown and otherwise healthy-looking broilers found dead on their backs”. Its Key Points close on this: “No pathognomonic lesions or diagnostic tests are available.”

All four rows are MSD Veterinary Manual, each with its own Full Review date, and each describes commercial housing under a level of control a bakuran lacks. The last column is the point of the table: three of the four rows end at a necropsy, and the fourth has nothing at all that settles it.

Read the four rows across and the limit of any pattern is visible at a glance. Ascites syndrome kills the same kind of bird, fast-growing and more often male, and that page says “affected broilers frequently die on their backs” and that “death may occur suddenly, before clinical signs are observed”. Same bird, same posture, different cause, and a right ventricle a keeper cannot see is what separates them. Egg peritonitis widens it past broilers: in a laying flock it can “give the appearance of an infectious disease”, and it “is diagnosed at necropsy”. Necrotic enteritis notes that “early mortality is often related to concurrent coccidiosis”, a separate page’s subject.

One more thing about that first page, because it is the one most often misread. Two percentages sit on it and they measure different things: “0.5%–4% of broiler flocks” is the share of flocks affected, while “0.5%–9.6%” is cumulative mortality inside a flock. The controls the Merck page lists are management ones, “slowing the growth rate of broilers, particularly during the first 3 weeks of life” among them, and the page names no drug.

Saan sa loob ng batch nahuhulog ang mga namamatay?

One Philippine paper splits a batch’s losses in two, and it is Ancog et al. (2023), a life cycle assessment of broiler production out of UPLB. On printed page 96 it counts nine houses: “There were four conventional and five tunnel-ventilated houses investigated for this study.” It gives head counts for each house type at placement, at the end of brooding and at harvest, and it prints no rate, so the percentages below are mine.

Head counts read at Ancog et al. (2023) p. 96. The coop article reads the same counts as a housing and density finding and prints the two placement-to-harvest figures.

The two house types lost a similar share overall, 6.2% against 4.8%, in opposite halves of the batch. In the open-sided houses 813 of the 1,119 birds lost went during brooding; in the tunnel houses 1,182 of 6,505 did. A keeper who watches the brooder closely and relaxes at three weeks is watching the right half of one batch and the wrong half of the other. Their peso value, priced by the day each died, belongs to another page.

Malaking bagay iyan sa pagtatala. Maliliit pa ang sisiw sa unang linggo at magkakadikit sa init, kaya madalas ay hindi mo agad namamalayan na kulang na sila ng dalawa. Sa ikaapat na linggo, halata agad ang bawat isang nawawala. Kaya puwedeng mabagal ang simula ng tala mo at mabilis ang dulo, samantalang pareho lang pala ang bilis. Ang artikulo sa brooding ang may hawak ng mga numero para sa unang linggo.

Five ways a mortality record goes wrong

1. The mistake: Reporting a count with no denominator: "three of my chickens died".

   Do this instead: Report the count, the age group, and how many birds of that age were alive at the time.

   Annex 10 § 4 column five asks for the "Total population of that age group where mortalities were observed". Three of six and three of four hundred arrive at the office as the same sentence and mean opposite things.

2. The mistake: Merging the two percentages on the sudden death syndrome page into one figure.

   Do this instead: Keep them apart: 0.5% to 4% is the share of flocks affected, 0.5% to 9.6% is cumulative mortality within a flock.

   They have different denominators. MSD Veterinary Manual prints both on the same page, at Full Review July 2024, and quoting either as "the mortality rate" states something the reference does not.

3. The mistake: Taking a midpoint out of a quoted range, so that "2% to 50%" becomes 26%.

   Do this instead: Quote the range as a range, including when it is uselessly wide.

   A range that wide is a statement about how variable the condition is. Averaging its ends produces a figure no source published and no flock ever showed.

4. The mistake: Reading a pattern as a diagnosis, then deciding the call can wait.

   Do this instead: Treat the pattern as the thing you hand over, and let the naming happen where the naming is done.

   Section 2.1.2 of the AIPP-MOP, printed on page 40, defines a smallhold suspect case as "any unexplained mortality in the flock". Unexplained is the trigger, so working out an explanation for yourself is the one move that removes your own grounds to ring.

5. The mistake: Assuming the six-week table can be reconstructed later.

   Do this instead: Keep the dates as they happen, even as three words in a notebook, because the dated part is the part that decays.

   Annex 20 § 6 asks for deaths in each of the six weeks before onset. Week six of that table was an ordinary week in which nothing seemed worth remembering, which is exactly why nobody remembers it.

What would make this page better?

A keeper can fill in Annex 20’s six-week table today, and there is still nothing published to lay a filled-in one beside. That is logged as gap G-1, open, covering backyard flock performance under Philippine village conditions.

So a careful keeper ends up holding a curve of their own with no published curve to read it against. Ancog’s nine houses are the closest thing in print: commercial houses at two densities, split into two phases and never plotted week by week.

What would move G-1 is a body of these tables, filled in by ordinary flocks and averaged, and that is the one thing the annexes cannot produce on their own. A form is opened after something has already gone wrong, so the flocks that never had a bad month never file one. That is a survivorship problem sitting inside the state’s best instrument.

BAI has designed the most detailed mortality schema I found in a Philippine issuance and pointed it at outbreaks. Point the same schema at an ordinary month and it becomes the survey G-1 has been waiting for.

Questions people actually ask

What does BAI actually ask for when chickens die?

Annex 10 § 4 of the 2025 Avian Influenza Protection Program Manual of Procedures, printed on page 120, sets out six columns: every date a death was observed, what was seen on each date, the age group of the affected birds, whether samples were collected and what came back, the total population of that age group, and which farm house the deaths occurred in. Five of the six are answered by the keeper and one is answered by a laboratory.

How far back does the investigation look? Show the answer

Six weeks. Annex 20 § 6 of the same manual, printed on page 156, is headed WEEKLY MORTALITY and its note reads "data concerning mortality rates recorded in the 6 weeks prior to the onset of clinical signs". The table is laid out as WEEK, subdivided into FROM and TO, against NUMBER OF ANIMALS DEAD, and it counts backwards from a date only the keeper can supply.

Can a pattern of deaths tell me which disease it was? Show the answer

It reaches a class of cause and it stops short of a name. MSD Veterinary Manual describes sudden death syndrome as well-grown broilers found on their backs with deaths peaking between 2 and 4 weeks, and its Key Points, at Full Review July 2024, end on the line "No pathognomonic lesions or diagnostic tests are available." Ascites syndrome kills a similar bird in a similar posture and is told apart at necropsy. The name comes from a laboratory, and the pattern is what you hand over to one.

Why does the form ask how many birds were still alive? Show the answer

Because a count of deaths without its denominator cannot be read. The fifth column of Annex 10 § 4 asks for the "Total population of that age group where mortalities were observed", and Annex 20 § 5 asks for an Estimated Population At-Risk within the farm, within a 3 km radius and within a 10 km radius. Three dead birds is a count. Three of forty at five weeks, on three named dates, in one house, is a report.

What if I did not write anything down? Show the answer

Ring anyway, and say what you know. The manual asks the same questions of a backyard flock as of a commercial one, and the first line of Annex 20 § 1 is "TYPE OF FARM: Backyard ____ Commercial ____". The parts of the record that cannot be recovered are the dated ones, so the value of a notebook is entirely in having kept it before anything was wrong.