45-days-broiler-manual

Disease Prevention and Control

Broiler production has developed into a large-scale industry during
the past two decades. However, its further development is deterred by
some constraints. One major problem is the prevalence of infectious
diseases caused by bacteria, viruses, mycoplasma, and/or parasites.
Losses from feed containing mycotoxins and from non-infectious
diseases such as sudden death syndrome (SDS), ascites, and leg
disorders, which adversely affect fast-growing chickens are among the
recent problems confronting the broiler industry.

Over the years, biosecurity measures based on disease infection
and transmission mechanisms have been developed to protect the health
status of the flock. With the use of effective vaccines, anti-microbial
agents, extensive health management systems, and continuous research,
it is hoped that losses from poultry diseases will eventually be controlled
and minimized.

Vaccination

Vaccination is an effective and economical means of preventing
infectious poultry diseases. Vaccines are biological products prepared
from the organisms causing the disease. Live vaccines are available
against most viral diseases. However, availability of bacterins against
bacterial infections is still limited. Live vaccines consist of living
attenuated organisms capable of replicating in the chicken to induce
immune response or antibody production. There is always a time
interval between the administration of a vaccine and the appearance of
protective antibodies. This usually takes 10–14 days after initial
vaccination with a live vaccine. Vaccinated chickens, therefore, never
become immunized immediately upon vaccination, but only after an
interval of time.

The presence of high levels of egg-transferred antibodies (maternal
antibodies) in chicks may seriously interfere with vaccine responses. If
present, maternal bodies may destroy or neutralize the viruses in
vaccines that may result in a significantly shortened period of protection
or failure of the chicken to produce antibodies. Chicks are not

38 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

immunologically competent or capable of fully responding to vaccines
until they are 6 weeks of age. It is for these reasons that there is often
the need to revaccinate chicks when they are immunized at day-old or
during the first week of life.

Post-vaccination reaction such as decreased feed consumption and
development of mild respiratory symptoms may be observed after
vaccination with live vaccines for respiratory diseases (e.g. NCD, IB).
Often, this problem is associated with poor environmental conditions,
improper management, and rough handling of chickens during vaccination.
In this case, post-vaccination reaction may cause concurrent infection
such as chronic respiratory disease (CRD) to become more severe. To
avoid severe vaccination reactions, only healthy chickens should be
vaccinated following proper vaccination procedures.

A vaccination program should be developed based on disease
history of the area where the poultry farm is located. An example of a
typical vaccination program for broilers is shown in Table 9.

Table 9. Vaccination schedule for broiler chicks.

Age of Route of

Chicken Type of Vaccination Administration Remarks

7–10 days NCD (B1 strain) + Intraocular Chicks from
IB (live vaccine) (eye drop) unvaccinated
Intranasal parents may be
(nose drop) vaccinated
as early as 1–3
days of age

7–15 days IBD, mild or Via drinking If chicks are
intermediate strain water vaccinated before
(live vaccine) 7 days old,
re-vaccination at 21
days of age may be
indicated for
optimum protection.

21–28 days NCD (La Sota strain) Via drinking

+ IB (live vaccine) water

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 39

Vaccination Failure

Occasionally, vaccines may fail to immunize or adequately protect
chickens from field pathogens due to the following reasons:

1. Administration of vaccines that do not contain the appropriate strain
or serotypes of the pathogen causing the disease

2. Decreased vaccine potency due to improper storage and/or handling,
or use of expired vaccines

3. Improper method of administering the vaccine or giving of inadequate
dosage

4. Presence of high levels of maternal antibody that interferes with the
immunization process, particularly in very young chicks

5. Stress, incomplete development of immuno-competence, poor
nutrition, mycotoxin, presence of concurrent immunosuppressive
infections (e.g., IBD, CRD, coccidiosis) that tend to cause less
effective or incomplete immune responsiveness to vaccines

Vaccination Tips

1. Purchase recommended strain/type of vaccines from reliable sources.
2. Keep vaccines cool at all times. They are best stored in the

refrigerator at 4oC where they are kept cold, but not subjected to
freezing and thawing.
3. Put vaccines in an icebox during transport.
4. Take note of the expiry date, which is stamped on each packet of
vaccine. Vaccines lose potency slowly even when stored under
ideal conditions. Vaccines should be purchased as required, stored
properly, and used within the expiry period.
5. Follow strictly vaccination schedule and proper use of vaccines as
indicated by the manufacturer.
6. Administer the correct dose. Dosages should not be decreased nor
increased unnecessarily.
7. Vaccinate healthy chickens only. Do not vaccinate the flock when
there is an outbreak of disease in the farm (e.g., infectious coryza,
coccidiosis, CRD, etc).
8. Administer live vaccines within 1 hour after reconstitution. Keep
vaccines cool during vaccination time.
9. Avoid unnecessary stress during vaccination. Anti-stress supplement
may be given via the drinking water at least 2 days before and 3 days

40 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

after vaccination that requires individual handling of chickens (e.g,
intraocular or intranasal route of administration).
10. Destroy unused reconstituted live vaccines. Burn or bury empty
vials/bottles and leftover live reconstituted vaccines.
11. Check or monitor the immune response to NCD or IBD live
vaccines by using the hemagglutination-inhibition (HI) test of
ELISA, 10–14 days after each NCD or IBD vaccination. These
tests are conducted in most diagnostic laboratories. Revaccinate
flock if the protection or antibody titer is low.

Medication

Most viral diseases of poultry can be prevented by vaccination and
management procedures. However, there are instances where the use
of appropriate chemotherapeutic agents is necessary for the prevention
or treatment of some bacterial or parasitic diseases for which no vaccine
is available.

In poultry, mass medication through the feed or drinking water has
been a labor-saving practice. Most chemotherapeutic agents are
incorporated in the feed. When chickens are sick, however, medication
via the drinking water is preferred over feed medication because sick
chickens may not have the appetite to eat but will continue to drink.

The amount of chemotherapeutic agent added to the feed or
drinking water is a concentration usually expressed as grams per ton or
parts per million (ppm). This always refers to the active drug ingredient.
The average dose rate can be calculated from the average daily intake,
the concentration of the chemotherapeutic agent, and the average body
weight of the chickens in the flock.

The commonly used therapeutic agents, if administered correctly,
are generally free of toxic effects; however, prolonged use of anti-
microbial agents at low levels can lead to the development of resistance
by microorganisms to those agents. In general, about 5 days of
medication is required for the successful treatment of a bacterial
disease. Sometimes, however, there may be a need to resume treatment
after 2–5 days to prevent the disease from resuming its course upon
withdrawal of the drug. Requirements for successful anti-microbial
therapy include clinical diagnosis, isolation and identification of the
causative pathogen, drug sensitivity testing to provide the basis for
selecting the anti-microbial drug, correct dosage and route of
administration.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 41

The continued use of chemotherapeutic agents such as antibiotics
in animal feeds also requires adequate attention since drug residues in
animal tissues can be a risk to human health if the animal is slaughtered
before the recommended withdrawal period. It is therefore, strongly
recommended that all medications in the feed or drinking water be
withdrawn at least 5 days prior to slaughter. The following are common
medications given to broiler chickens.

1. Anti-stress preparations (e.g., antibiotic-vitamin-electrolyte
supplements) may be given via the drinking water during the first 3–
5 days of age, and 2 days before and 3 days after each vaccination
with live virus vaccine that requires individual handling of the
chickens for its administration.

2. Coccidiostatpreparationsshouldbegivencontinuouslythroughthefeed
from the 1st day to 28th day of age. Observe proper withdrawal period.

3. Anti-malarial preparations (e.g., pyrimethamine-
sulfamonomethoxine/ sulfadimethoxine plus vitamins) may be given
in the feed or drinking water, starting at 10–14 days old for 2
consecutive days each week for 5 weeks if the disease is prevalent.
Observe proper withdrawal period.

Sanitation

Sanitation is very important to the modern intensive system of
poultry production where the continuous rearing and high animal density
often lead to a disease build-up. Although vaccination helps in the
development of the flocks’ resistance to diseases, it is still necessary to
keep exposure to disease-causing organisms to a low level as possible.
Proper cleaning and disinfecting of poultry houses, premises, and
equipment reduce microbial challenge in the environment and allow
vaccination to be more effective. Thorough cleaning and disinfecting
also provide the only effective way of breaking the cycle of infection in
the farm.

Cleaning and Disinfection

1. Cleaning must precede disinfection since the potency of most
disinfectants may be greatly reduced by organic matter (e.g.,
dropping, feed dust accumulation).

42 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

2. Cleaning is best accomplished by the use of pressure hose with or
without a detergent.

3. Disinfectants do not act instantly, thus time must be allowed for their
germicidal effect.

4. Most disinfectants act more effectively when applied in solution,
because solutions penetrate a greater depth, thus killing more
organisms.

5. A disinfectant intended for decontamination of buildings should
work well in the presence of a moderate amount of organic matter.
It should be compatible with soap or detergents, safe to building
materials, and relatively non-toxic to man and animals.

6. A disinfectant must be readily soluble even in hard water, effective
against a wide variety of infectious agents (e.g., viruses, bacteria,
fungi, protozoa), free from objectionable or lingering odor, readily
available, and inexpensive.

Disinfectants for Poultry Farms

1. Phenolic compounds (e.g., cresol, orthophenyl-phenol, and
orthobenzyl-parachlophenol)

Indications:
! Foot dips
! Routine disinfection of poultry houses, premises, and

equipment before restocking or after outbreak of disease.

2. Organic iodine combinations/iodophores (e.g., povidone-iodine)

Indications:
! Final disinfection of poultry houses and equipment. These

compounds are most effective on clean surfaces.

3. Quaternary ammonium compounds/quats (e.g., benzalkonium
chloride, benzathonium chloride, cetylpyridinium chloride)

Indications:
! Final disinfection of feeders, waterers, and other equipment.

Effective on clean surfaces.
! Water sanitizer

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 43

4. Hypochlorite (e.g., chlorine)

Indications:
! Final disinfection of feeders, waterers, other equipment.

Effective on clean surfaces.
! Water sanitizer

5. Combinations of organic acids, organic biocides, and surfactants

Indications:
! Final/terminal disinfection of poultry houses and equipment

before restocking.

6. Glutaraldehyde-dimethyl ammonium chloride complex

Indications:
! Routine disinfection of poultry houses, premises, and

equipment before restocking and after a disease outbreak.
! Wheel/foot dips

Health Management Tips

1. Raise only healthy and vigorous stocks.
2. Feed chicken with nutritionally balanced rations and provide fresh

drinking water at all times.
3. Implement a vaccination program for prevalent diseases. Follow

strictly the vaccination schedule.
4. Provide comfortable housing with good ventilation and maintain

clean surroundings.
5. Construct poultry houses in such a way that wild birds and rodents,

which may serve as carriers of diseases, cannot enter.
6. Avoid overcrowding by providing adequate floor space and enough

feeding and watering spaces.
7. Fence the production area to provide ample protection against

scavengers and stray animals, which may be vectors of disease.
8. Practice an all-in-all-out method of operation if possible. Clean and

disinfect poultry houses after depopulation and allow cleaned and
disinfected buildings at least 2 weeks rest period before restocking.
9. Only flockmen should be allowed into the broiler houses. Visitors
and other unauthorized persons should stay off the production area.

44 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

10. Control flies and blood-sucking insects by applying suitable
insecticide. Provide good drainage and remove piles of trash,
unused equipment, and unnecessary junks, which could serve as
breeding places for insects and rodents.

11. Provide foot dips at the entrance of poultry houses to keep disease
out of any house and to prevent the spread of infections within the
farm through the movement of farm personnel.

12. Dispose sick and dead chickens by burning or burying. Sick
chickens could contaminate feed, water, and equipment with their
excrements.

13. Minimize activities that will cause unnecessary stress to the chickens.
14. Keep honest and accurate health and production records. Health

records should include vaccination, medication, and all health
problems encountered in the farm. Production records usually
include daily feed consumption, weight gains, and mortalities. Daily
evaluation of these records is recommended.
15. Consult a veterinarian at the first sign of disease in the flock. A
veterinarian is in a better position to make a diagnosis, advise on
medication and other biosecurity measures to prevent spread of the
infection.

Common Diseases of Broiler Chickens

NCD (Avian Pest)

An acute rapidly spreading respiratory disease characterized by
harsh breathing, coughing, sneezing, and often followed by nervous
manifestation.

Cause:
! Newcastle Disease Virus (NDV) - a paramyxovirus

Transmission:
! Direct contact with infected broiler
! Contaminated farm equipment, feed, or water
! Farm personnel and visitors with contaminated clothing and

footwear
! Free-living birds, (e.g., sparrows) and imported exotic

psittacine birds, which are often carriers of NDV

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 45

Symptoms:
! Drop in feed intake
! Respiratory signs such as gasping, coughing, sneezing,

rales, nasal discharge, often followed by neurologic signs
(e.g., incoordination, leg and/or wing paralysis, twisting of
head and neck)
! Marked variation in morbidity, mortality, signs, and lesions
due to the degree of chicken susceptibility and virus
pathogenicity.
! Common post-mortem lesion is proventricular hemorrhages
(Fig. 13).
! Poultry flock affected with NCD may show high mortality,
acute onset with various respiratory and gastrointestinal
lesions.

Fig. 13. Proventiculus of broiler chicken with hemorrhagic lesions.
Prevention:
! Vaccinate healthy flocks with live, attenuated vaccine.
! Thoroughly clean and disinfect farm equipment and

premises.

46 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

! Keep backyard chickens, fighting cocks, and exotic birds
out of the farm and its premises.

! Bird-proof poultry houses.
! Quarantine farm and isolate sick chickens from the healthy

ones as soon as NCD disease outbreak is suspected.
! Mix supportive medication with broad-spectrum antibiotic

in drinking water to prevent or reduce severity of secondary
bacterial infections.
! Depopulate and thoroughly clean and disinfect premises,
especially after a disease outbreak.

IBD (Gumboro Disease)

A highly contagious disease primarily affecting broiler chickens
between 2 weeks and 6 weeks of age, characterized by edema and
swelling of the cloacal bursa resulting in marked immunosuppression.

Cause:
! Infectious bursal disease virus (IBDV) - a birnavirus

Transmission:
! Direct contact with infected chickens
! Fecal-contaminated feed, water, and equipment
! Poorly cleaned poultry house and premises
! Transported from farm to farm by wild birds, rodents, and

insects

Symptoms:
! Droopy appearance, ruffled feathers, marked depression,

lack of appetite.
! Diarrhea, soiled vent, trembling due to dehydration
! Chickens tend to pick at their vent

Prevention:
! Vaccinate with mild or intermediate live vaccine.
! Require strict sanitation. Thoroughly clean and disinfect

poultry houses and equipment with iodophore-based
disinfectant.
! Practice all-in-all-out system of operation and allow a rest
period of at least 30 days between batches.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 47

Fowl Pox

A viral infection characterized by formation of scab-like lesions on
the skin of the legs and head and/or formation of yellowish membranous
plaques on the mucous membrane of the oral and pharyngeal cavity.

Cause:
! Avipox virus

Transmission:
! Direct contact with infected broilers
! Mosquitoes and other blood-sucking flies through their bites

Symptoms:
! Dry/Skin form: papules, vesicles, pustules, and scab-like

lesions on the unfeathered skin of the head and legs
! Wet/Diphtheritic form: raised, yellow plaques on mucous

membranes of mouth and pharynx, which may induce
inappetence and difficulty in breathing

Prevention:
! Vaccinate broilers in areas where the disease is common

with pigeon or chicken pox virus strains.
! Mix broad-spectrum antibiotic in drinking water to prevent

aggravating secondary bacterial infection if disease outbreak
occurs.

Infectious Bronchitis

A highly contagious respiratory disease of chickens characterized
by rapid spread, respiratory signs without nervous system involvement.

Cause:
! Infectious bronchitis virus (IBV) - a coronavirus

Transmission:
! Air-borne or aerosol transmission, direct contact with sick

birds
! Contaminated feed, water, equipment, premises

48 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Symptoms:
! Gasping, coughing, tracheal rales, and nasal discharge
! Chicks appear depressed and huddle under the heat source.
! Poor appetite
! A cloudy airsacs (airsacculitis) (Fig. 14) is a common

pathologic sign.

Fig. 14. Broiler's abdomen with cloudy airsacs.
Prevention:
! Vaccinate broilers with live attenuated virus vaccine in

areas where the disease is common.
! Practice sanitation and sound management practices.
Infectious Coryza (IC) or Roup/Cold
An acute respiratory disease of chickens generally limited to the
upper respiratory tract. This disease is considered to be of economic
importance in many parts of the world.
Cause:
! Bacterium: Hemophilus paragallinarum (sero-types A,

B, C).

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 49

Transmission:
! Direct contact with infected birds/recovered carrier birds
! Airborne
! Contaminated feeds, water, equipment, and premises

Symptoms:
! Watery discharge from the eyes and nostrils, which later

becomes sticky, thick, and odorous
! Swelling of the face and eyelids
! Sneezing, respiratory rales, snicking
! Decreased feed intake

Prevention:
! Follow all-in-all-out type of operation.
! Provide good ventilation to reduce ammonia fume.
! Follow strict sanitation and sound management practices.
! Medicate with broad-spectrum antibiotics after stressful

conditions, e.g., vaccination and weighing.
! Avoid overcrowding.

Colibacillosis (E. coli)

A septicemia frequently occurring as secondary to respiratory and
other infections

Cause:
! Bacterium: Eschericha coli

Transmission:
! Inhalation of infected dust
! Fecal-contaminated feeds or water and equipment
! Unsanitary poultry houses and premises

Symptoms:
! Symptoms vary according to portal of entry and syndrome

induced.

In-Chicks:
! Omphalitis (navel infection) - inflamed navel; distended

abdomen due to yolk sac infection; abnormal color and
smell of yolk sac content; depressed chicks

50 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

! Enteritis - watery dropping, depression, inflamed intestinal
tract

! Air sacculitis - thickened air sacs with yellow, cheesy
exudate, pericarditis, perihepatitis, and peritonitis

Prevention:
! Avoid predisposing conditions such as overcrowding, poor

ventilation, high ammonia level, and poor brooding
management.
! Apply preventive medication with broad-spectrum
antibiotics in the drinking water during certain critical and
stressful periods in the chickens’ life.
! Follow strict sanitation in the farm and hatchery.
! Chlorinate drinking water if positive for E. coli.

Mycoplasma Gallisepticum (MG) Infection
or Chronic Respiratory Disease

A lingering disease, which affects the respiratory tract. It is
characterized by slow growth, poor feed conversion, and inferior
carcass quality.

Cause:
! Pleuropneumonia-like organism: Mycoplasma

gallisepticum

Transmission:
! Often triggered by stresses such as high ammonia level,

poor ventilation, overcrowding, vaccination, concurrent
infection with NCD, IBV, or E. coli
! Transmitted from parent to chicks thru the egg
! Direct contact with infected birds
! Air-borne transmission
! Contaminated feed, water, farm equipment, and personnel

Symptoms:
! Respiratory rales, coughing, sneezing, oculonasal discharge
! Decreased feed efficiency and growth rate
! Mortality is low unless complicated by air sacculitis due to

E. coli

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 51

Prevention:
! Practice an all-in-all-out system of operation.
! Cleananddisinfectpoultryhousesandequipmentthoroughly

after removal of infected flock.
! Avoid stresses such as ammonia fumes, poor ventilation,

overcrowding, high temperature, and marginal nutrition.
! Apply medication with antibiotics specific against

mycoplasma (e.g., tiamulin, in the feeds or drinking water).
Do not medicate with tiamulin in conjunction with monensin
(a common anti-coccidial incorporated in feeds).

Mycotoxicosis

A poisoning with toxic substances of fungal origin.

Causes: There are three mycotoxins considered to be potentially
harmful to poultry:

! Aflatoxin - hepatotoxin produced by the molds Aspergillus
flavus and A. parasiticus

! Ochratoxin - a nephrotoxin produced mainly by A.
ochraceus but also by some species of Aspergillus and
Penicillium

! Trichothecenes (T-2) - a mycotoxin having an
epithelionecrotic effect produced by Fusarium spp. of
mold

Common sources of mycotoxin are moldy cereal grains used in feed
manufacture, as well as formulated feeds. Poultry litter may also be a
source of this type of toxin.

Symptoms:
Severity and type of clinical disease depend upon the type,
amount, time, duration of toxin ingestion, as well as age of the
chicken.

! Aflatoxin
- Aflatoxin level of 0.6 ppm induces increased
susceptibility to bruising and infectious diseases due to
immuno-suppression.

52 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

- About 1.5–2.5 ppm aflatoxin causes decreased feed
efficiency and impaired growth.

- About 5–10 ppm aflatoxin causes acute death from
liver necrosis and hemorrhage.

! Ochratoxin
- About 0.6–2 ppm ochratoxin causes marrow and
lymphoid depression and impaired growth.
- About 3–4 ppm ochratoxin level in the diet causes
kidney damage, diarrhea, dehydration, emaciation, and
death.

! Trichothecenes (T-2)
- About 4–8 ppm T-2 toxin level in the diet causes oral
mucosal ulcers, gastroenteritis, increased susceptibility
to bruising, and impaired growth.
- About 8 ppm T-2 toxin and 3.5 ppm aflatoxin in the diet
have an additive effect of severely depressing growth
and weight gains in broilers.
- About 20 ppm T-2 toxin and 8 ppm ochratoxin
combination in the feed produce marked growth
depression and mortality.

Prevention:
At the feedmill level
! Use only cereal grains that meet quality specifications.
! Inspect and clean feedmill equipment and premises

frequently.
! Incorporate antifungal agents (e.g., organic acids such as

propionic acid and acetic acid) into the feed or cereal grains
such as corn to inhibit or retard mold growth and prevent
subsequent mycotoxin formation.
At the farm level
! Clean and disinfect thoroughly storage bins, hoppers, and
feeders between flocks.
! Avoid long periods of feed storage.
! Store feeds in cool and dry conditions.

Coccidiosis

A disease caused by protozoan parasites called coccidia, which
enter, multiply, and destroy the cells lining the intestinal tract.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 53

Cause:
! Cecal coccidiosis: Eimeria tenella
! Intestinal coccidiosis - E. acervulina, E. necatrix, E.

maxima and other species
Transmission:
! Ingestion of sporulated oocyst in fecal-contaminated feed,

water, and litter
! Mechanical transmission by contaminated footwear and

farm equipment
! Mechanical carriers such as rodents, flies, beetles, and wild

birds
Symptoms:
Symptoms vary greatly depending on the severity of the
infection and species of Eimeria.
! Depression, ruffled feathers, loss of appetite
! Blood-stained feces (Fig. 15)
! Decreased feed efficiency and growth rate
! Eimeria acervulina within the duodenum of the broiler

(Fig. 16)
Prevention:
! Apply coccidiostat in the feed or drinking water.

Fig. 15. Watery feces stained with blood.

54 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

! Observe strict sanitation. Provide footbath with disinfectant
at the entrance of poultry houses.

! Change or remove damp litter, especially during brooding.

Fig. 16. Theduodenumpartofthebroiler'sintestinesthatisinfected
with Eimeria acervulina.

Exudative Diathesis/Encephalomalacia
(Crazy Chick Disease)/Muscular Dystrophy

Nutritional disorders arising from Vitamin E and/or selenium
deficiency.

Cause:
Vitamin E and/or selenium-deficient diet or poor absorption of
these essential nutrients from the intestinal tract because of an
enteric disorder.
Symptoms:
! Exudative diathesis: Depression, sitting on the hock.

Subcutaneous edema, swelling underneath the beak and
wattles, and greenish-blue discoloration of the skin in the
abdominal region and under the wings
! Encephalomalacia: Softening of the brain seen during the
first 4 weeks of age (Fig. 17). Characterized by
incoordination, trembling, twisting of the neck, loss of
balance, falling on the side.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 55

! Muscular dystrophy: Depression, slow growth, whitish-
gray areas of muscle degeneration in the breast muscle
(Fig. 18)

Prevention:
! Use only quality feed ingredients and stable forms of

antioxidant and vitamin E in the feed.
! Store feed properly. Use feed on the first-in-first-out basis.

Fig. 17. Softeningofthebrainduetodegenerativechangesinnervous
tissue.

Malabsorption Syndrome
(Pale bird syndrome, helicopter disease, brittle bone disease, infectious

proventriculitis, femoral head necrosis). This syndrome is characterized
by poor feathering, runting, leg weakness, and osteoporosis.

Cause:
Several reoviruses are suspect cause of the disease, with
nutrition and management as contributing factors.

56 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Fig. 18. Breast muscle with whitish-gray area.

Transmission:
! Reoviruses transmitted vertically through the eggs of

infected hens
! Horizontal spread by direct contact with feces and

contaminated feed, water, and equipment

Symptoms:
! Stunted growth
! Abnormal feathering, paleness of skin
! High incidence of leg weakness
! Diarrhea

Prevention:
! Obtain chicks from reovirus-vaccinated breeders.
! Cleananddisinfectpoultryhousesandequipmentthoroughly

following disposal of broilers.
! Allow at least 2 weeks break before restocking the farm.
! Mixbroad-spectrumantibioticsindrinkingwatertominimize

secondary bacterial infection; vitamin-electrolyte
preparation in drinking water may help avoid vitamin
deficiencies and dehydration.
! Provide nutritionally balanced diet and good management.

SDS (Sudden Death Syndrome) or Flip-Over Disease

A condition afflicting heavy, fast-growing broiler chickens, mostly
males between 2–6 weeks of age characterized by sudden death from
no apparent cause.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 57

Cause:
The cause is unknown but it is suspected to be a result of
physiologic and nutritional interactions. It is believed that a
combination of low level or bioavailability of biotin and stress
associated with rapid growth could precipitate SDS.
Symptoms:
! None; chickens suddenly convulse and die within

1–2 minutes with no premonitory signs.
Prevention:
! Induce a period of initial slow growth through physical feed

restriction and/or use of low-nutrient density rations can
reduce the incidence of the condition..
! Provide adequate amount of biotin in the diet.
Other diseases of broilers are listed in Appendix 1.

58 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Farm Records

Importance

Keeping the records “up-to-date” and accurate is a must in the
broiler business. It should be made part of the regular activities in the
farm. Records give ready and reliable information about the general
performance of the business.

With good records, one can compute the production cost, which may
be used in pricing and in the adjustment of operations. The whole
financial status of the business can also be measured. Knowledge of
feeding efficiency, health conditions, and program of operations is an
important consideration for efficient management.

Farm records also provide the basic data in the planning of
succeeding business operations. They also facilitate the flow of
information for credit purposes. The overall efficiency of business can
only be quantified if records are accurate.

Broiler Record

A simplified farm record has been developed especially for
independent broiler raisers (Appendix 2). This may serve as a guide to
all broiler producers and must be the minimum information needed in
flock management. Farm record must include the following:

- Strain and source
- Date and number of chicks received
- Average body weight of day-old chicks
- Feed consumption
- Water consumption (if possible)
- Mortality
- Medication
- Vaccination
- Feed Delivery
- Sales of broilers and by-products such as empty feed bags

and manure

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 59

At the end of the growing cycle, feed conversion efficiency is
calculated from the data on total feed consumption over total weight of
broilers harvested. All other variable costs are computed at the end of
the growing cycle.

Record keeping for contract growers is a part of the company’s
requirements. Each company has its own set of records, the basic parts,
however, are similar.

Measuring Income from Broiler Enterprise

The cost items that can be derived from the broiler records include
chicks, feeds, labor, supplements, and vaccination and medications
applied. Other items that should be included as production costs are
shown in sample form (Appendix 3).

Methods of measuring income vary, depending upon the purposes
and the scale of operations. For producers who are interested only in
cash transactions, net cash income may be used as the first measure.
This is attained by subtracting all cash expenses from cash receipts,
which include sales from broilers, manure, and feedbags. Cost items
that do not involve cash outlays should not be included in this measure.
One alternative, therefore, is to include all costs; cash and non-cash cost
may include depreciation of all equipment used in the operations on the
farm and the value of family labor employed in the business. Non-cash
receipts, on the other hand, include the value of broilers used at home and
for other purposes. Total net income derived by subtracting the total cost
from total receipts. This measure represents the return to operator’s
labor, management, and to fixed investment.

Efficiency Indicators

Feed Conversion

This measures the quantity of feeds used to produce 1 kg of broiler
liveweight. It can be obtained by dividing the total kilogram of feed
consumed by the number of kilogram of liveweight broiler produced.

Example:
3.5 kg feed consumed
= 2.0

1.75 kg liveweight broiler

60 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

This indicator is important in determining the relative efficiency of
feed formulation and quality of the rations.

Feed Cost/Kilogram of Broiler Produced

This is determined by multiplying the feed conversion by the cost of
feed per kilogram.

Example:

2.0 x P18.82/kg feed = P37.64 feed cost/kg broiler produced

Production Efficiency Factor (PEF)

This is a standard measurement for determining broiler performance.
The factors involved are harvest recovery, average live weight,
harvestable age, and feed conversion efficiency. Using this method, one
can compare performance with other growers. Within a given farm, one
can compare the performance of one broiler house from the other broiler
houses. This is useful, especially in giving workers incentives on the
basis of overall performance. The formula is as follows:

PEF = HR (%) X ALW (kg) X 100

Age X FCR

Where:
PEF = Performance efficiency factor
HR = Harvest recovery (%)

ALW = Average live weight (kg)
Age = Harvestable age (days)
FCR = Feed conversion ratio

Note: “The higher the value of PEF, the better is the performance.”

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 61

Broiler Marketing

Quality

Sell high-quality broilers. Quality is the result of careful and efficient
production and marketing practices. Ultimately, final consumers
determine whether the quality of the farmers’ produce is acceptable or
not. This information is relayed to the grower by the wholesale buyer
by means of the regularity of purchases, and even the offer of higher
than average farmgate prices in the locality.

Timing

Sell finished broilers at the optimal age of not more than 42 days, with
the chicken having attained a body weight of 1.75 kg. Delaying the sale
of the chickens may increase body weight, but this may reduce profits
since feed efficiency falls, as older chickens require greater amounts of
feed for every additional unit of body weight gained.

Market Outlets

Initially, arrangements should be made in the marketing of the output
with regular and reputable buyers of broiler chicken. The stability of the
market base is very important in starting out any business venture. This
tests the capability and discipline of the grower to meet certain industry
standards on a continuous basis.

For the more adventurous and experienced growers who want to be
independent, various market outlets can be explored. Delivery
arrangements could be contracted with local hotels, restaurants, fastfood
outlets, and supermarkets. Arrangement could also be made with well-
known, established, and respectable broiler buyers or traders in the
locality.

Finally, the local wet market can also be explored. It is important
to be informed, however, whether the local market has the capacity to
regularly absorb all outputs scheduled for disposal, considering the scale
of the independent grower.

62 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Price Fluctuations
Prices of broilers are totally determined by the seasonal behavior of

demand for and the supply of chicken meat in the relevant market of the
produce. Prices are not within the control of the producer. For this
reason, the grower has to be very keen on the seasonal behavior of
demand, production, and prices.

It is very difficult, if not impossible, to establish how much broiler
chicken is being produced in each season, as the year progresses. It is,
however, possible to get a feel of how prices behave throughout the
year.
Broiler Inventory Holding

Another guide for growers in the operations of the farm could be the
historical broiler chicken inventory in the country over the last six years.
This shows estimate of the number of head of broiler chicken all the
farmers in the country held at a particular time during the year.
Inventory holding at a certain period represents the number of head that
are being grown for slaughter, and also those that are about to be sold.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 63

Cost-and-Return Analysis

One of the most commonly used measures in determining the
profitability of an enterprise is the cost-and-return analysis, also called
the enterprise analysis. The net income can be computed by deducting
the total costs from the total returns.

Costs

Costs are two major categories: investment and operating costs.
Investment costs are associated with starting the project, and maintaining
it over the lifetime of the activity. Operating costs refer to the day-to-
day expenditures that have to be incurred to produce the output
projected.

Investment Costs

The major investment costs are incurred on the first year, on the
year of the establishment of the broiler farm. The amount of investment
depends on the scale of the project.

The major investment items are the following: (a) buildings/housing,
(b) equipment, and (c) site development. While housing and equipment
costs would directly depend on scale, site development cost is assumed
to be the same, whether the scale is for a 10,000-chicken model or a
5,000-chicken model, as the proposed area to be developed is the same.
Only the size of housing would vary.

Equipment. It includes (a) brooding heaters, (b) regulators and gas
lines, (c) feeders, and (d) waterers. The waterers used here are of the
automatic type. To account for replacement investments over the life
of the project, the heaters and waterers have a 5-year lifespan each.
The tube feeders have a lifespan of 3 years. Cost of replacement
investment shall take the place of depreciation costs.

Operating and Maintenance Costs

Operating and maintenance costs cover the costs of the following:
(1) DOCs; (b) feeds; (c) medicines, vaccines, and feed supplements;

64 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

(d) utilities; (e) brooding; (f) repairs and maintenance; (g) labor; and
(h) miscellaneous expenses.

Except for labor costs, all other costs are pro-rated on a per chicken
basis. For all such expenses, operating and maintenance costs depend
on the scale of operations.

Cost per cycle is calculated on a 42-day raising period. Extrapolated
to an annual basis, the frequency of five cycles per year is adopted.

The bulk of costs come in the form of expenses on feeds for the
chickens. The estimate for feed cost per chicken is calculated by using
the following standard parameters.

z Feed conversion ratio = 2.0;
z Weight of chicken at harvest = 1.75 kg; and
z Price of mixed feed = average of P941 per 50-kg bag.

The 10,000-Chicken Module

For the 10,000-chicken module, total operating cost over a 1-year
period is estimated at P4.997M. Of this, P3.29M or 65.45%, is
accounted for by feed expenses. The second major operating expenditure
item is on day-old chicks, set at P19.00/chick, amounting to P950,000/
year. This is 19% of the total. Feed and DOCs expenses, together,
account for 84.45% of total operating expenses.

The structure of operating and maintenance costs for a 10,000-
chicken module is shown in Table 10.

Returns

Returns from the project are assumed to start only one year after
the initial investment has been made. Main revenue comes from the sale
of finished broilers. The standard parameters that are used in calculating
the revenue from broiler sales are the following:

z Weight of chicken at 42 days = 1.75 kg;
z Price of chicken = P61.45/kg;
z Number of cycles per year = 5; and
z Mortality rate = 5%

On an annual basis, the returns from a 10,000-chicken module is
P139,231.25.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 65

Table10. Costandreturnfor10,000-chickencapacitybroilerfarm.

Items Amount (P)

Income
Sale of broilers ............................................................... 1,021,606.25
Sale of manure ...................................................................... 2,090.00
Sale of sacks ......................................................................... 3,500.00

Total ............................................................................. 1,027,196.25

Cost
Cash
Day-old chicks ............................................................. 190,000.00
Feeds ............................................................................ 654,100.00
Vaccines,medicine,etc. ................................................... 40,000.00
Electricity ....................................................................... 15,500.00
Brooding expense (LPG) .................................................... 18,500.00
Farm rental ......................................................................... 35,000.00
Haulingexpense .................................................................... 2,375.00
Repair and maintenance ...................................................... 12,500.00
Permits and licenses .............................................................. 1,200.00
Salaries ............................................................................... 25,175.00
Miscellaneous expenses ........................................................ 5,000.00

Total ............................................................................. 999,350.00

Net Income ........................................................................... 27,846.25

Assumptions:
1. Price of day-old chicks ........................................................ P19.00
2. Price of broilers ................................................................... P61.45/kg
Market weight is 1.75 kg
3. Feeds ................................................................................... P65.41/hd
4. Vaccines,medicine,disinfectant ............................................. P4.00/hd
5. Electricity .............................................................................. P1.55/hd
6. Brooding cost ........................................................................ P1.85/hd
7. Farm rental ............................................................................ P3.50/hd
8. Hauling cost ........................................................................... P0.25/hd
9. Repair and maintenance cost .................................................. P1.25/hd
10. Permits and licenses ............................................................... P0.12/hd
11. Salary .................................................................................... P2.65/hd
12. Miscellaneous ........................................................................ P0.50/hd
13. Volumeofmarketablemanure/chicken ..................................... 0.88 kg
14. Price of manure ...................................................................... P0.25/kg
15. Estimated revenue from manure/chicken ................................ P0.22

66 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Minor benefits are also realized from the sale of by-products. These
by-products are chicken manure and used feed sacks. Chicken manure
has a market in the processing of organic fertilizer. Roughly, the amount
of marketable manure generated per chicken is one-fourth the weight
of the total feed consumed. In calculating the quantity and value of
marketable manure per chicken, the following parameters are used:

z Feed consumption/chicken = 3.5 kg;
z Marketable manure recovery factor = 0.25;
z Volume of marketable manure/chicken = 0.875 kg;
z Price/kg of manure = P0.25 kg; and
z Estimated revenue from manure/chicken = P0.22/chicken.
Assuming five batches per year, at 5% mortality, revenue per year
from sales of manure is P10,450.00 for the 10,000-chicken module.
Used feeds sacks are priced at P5/sack. Each bag contains 50 kg
of feed. For the calculation of revenue from used sacks, the relevant
parameters used are the following:
z Feed consumption/1,000 chickens = 3,500 kg;
z No. of sacks/1,000 chickens =70 sacks;
z Revenue from sacks/1,000 chickens (@P5.00/sack) = P350.00;
Thus, for the 10,000-chicken module, annual revenue from used
sacks is P3,500.

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 67

References

Cobb Breeder Management Guide. 2005. Cobb-Vantress, Inc.,
Arkansas.

Esplana, E. R. and Bascuguin, M.D. 2005. Development of an early
warning system for broiler industry: focus on production
forecasting. Paper presented during the BAI Research and
Development In-House Review, BAI-APDC, Marulas,
Valenzuela City. July 21, 2005

Feed Reference Standards, third edition 2003. Philippine Society of
Animal Nutritionist (PHILSAN). Animal and Dairy Sciences
Cluster, UPLB Los Baños, College, Laguna.

Livestock Development Council. LDC Annual Report 2004. Department
of Agriculture, Elliptical Rd., Diliman, Quezon City.

National Academy of Science and Technology. 2005. NAST Agriculture
2020: Industry Strategic Plan 2020 – Swine-Poultry-Corn
Cluster (Draft). DOST Cmpd., Bicutan, Taguig, Metro Manila.

STRIVE Foundation 2004. Cross Country analysis of the Hog, Broiler
and Layer Industries of the Philippines, Thailand, Malaysia, and
Indonesia – Final Report. May 2004. Livestock Development
Council, Department of Agriculture, Elliptical Rd., Diliman,
Quezon City.

The Broiler Production Committee, 1997. The Philippines recommends
for broiler production. Los Baños, Laguna, Philippines:
PCARRD, 1997. 91 p. – (Technical Bulletin Series No. 10-B).

68 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Appendix 1. Other Diseases of Broiler

Pullorum Disease (Bacillary White Diarrhea)

An acute bacterial disease of chicks causing high mortality, especially
during the first 3 weeks of age

Cause:
Bacterium: Salmonella pullorum

Transmission:
z Egg transmitted (i.e., from hen to progeny chicks)
z Fecal-contaminated feed, water, and equipment
z Contact with infected chicks and contaminated hatchery

incubators and equipment

Symptoms:
z Chicks appear sleepy, weak, and anorexic
z Chicks chirp continuously and have pasty white diarrhea
z High mortality during the first 3 weeks of life
z Some respiratory signs (e.g., labored breathing)

Prevention:
z Purchase chicks only from reliable sources (i.e., pullorum-

free breeder farms and hatcheries).
z Observe strict sanitation.
z Avoid stress conditions.
z Mix medication with broad-spectrum antibiotics or

nitrofurans in feed or drinking water during the first 3 weeks
of life to lower mortality and transmission of disease.

Paratyphoid (Salmonellosis)

An acute septicemic disease similar to pullorum, which can cause
extremely high early chick mortality

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 69

Cause:
Bacteria: Salmonella organisms other than S. pullorum and S.
gallinarium.

Transmission:
z Fecal contamination of eggshells during the process of

laying or from contaminated nests, litter, or incubators
leading to infection at hatching time
z Fecal contamination of feeds or feed ingredients, water,
and equipment
z Rodents and their dropping may readily contaminate poultry
feeds
z Pigeons, sparrows, and other species of wild birds may
serve as source of infection

Symptoms:
z Chilled chicks huddle for warmth
z Weakness, ruffled feathers, loss of appetite, and increased

water consumption
z Watery diarrhea with pasting of the vent
z Moderate to high mortality

Prevention:
z Observe sound management practices.
z Reduce contact with rodents, wild birds, and flies.
z Observe strict hatchery and egg sanitation.
z Use Salmonella-free stock and only Salmonella-free feed

ingredients.
z Use of broad-spectrum antibiotics or nitrofurans in feed or

drinking water as preventive medication.

Aspergillosis (Brooder Pneumonia)

A fungal infection of the respiratory system of young birds

Cause:
z Fungus: Aspergillus fumigatus

70 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Transmission:
z Inhalation of large number of spores from moldy

environment, litter, and feed
z Unsanitary hatchery conditions

Symptoms:
z Gasping, gurgling, and harsh coughing
z Loss of appetite, weakness
z Nervous signs and eye lesions
z Moderate-to-high mortality

Prevention:
z Follow strict hatchery sanitation.
z Observe proper poultry house environment management

and sanitation.
z Store feeds properly to avoid moldy conditions.
z Remove moldy feeds and litter.

Leucocytozoonosis (Avian Malaria)

A disease caused by a blood protozoan parasite characterized by
anemia, weakness, and death.

Cause:
z Protozoa, Leucocytozoon caulleryi

Intermediate biological vector: Culicoides sp. or biting
midges

Transmission:
z Biological vectors feeding on carrier birds and later

transmitting the infection as they feed on susceptible birds

Symptoms:
z Depression, lack of appetite, weakness, tendency to huddle,

ruffled feathers
z Anemia
z Greenish diarrhea
z Mortality

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 71

Prevention:
z Applymedicationwithsulfamonomethoxine-pyrimethamine

in the feed or drinking water
z Control insect vector.

72 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION

Appendix 2. Broiler record.

s

PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION 73

Appendix 3. Sample form for computing income.

I. COST ________
Cash cost ________
Broiler chicks ________
MVS (medicine, vaccines, supplements) ________
Feeds ________
Electricity ________
Water ________
Hired labor
Interest on operating capital P ________

Total cash cost (A) ________
________
Non-cash cost
Depreciation P ________
Value of family labor P ________

Total non-cash cost (B) ________
Total Cost (C) = (A) + (B) ________
________
II. RECEIPTS
Cash receipts P ________
Broiler sales
Manure sales ________
Feedbags sold ________

Total cash receipts (D) P ________
P ________
Non-cash receipts
Value of broiler used home P ________
Value of broilers used for promotions P ________

Total non-cash receipts (E)
Total receipts (F) = (D) + (E)

III. MEASURES OF INCOME

1. Net cash income (D - A)
2. Total net income (F - C)

74 PHILIPPINES RECOMMENDS FOR BROILER PRODUCTION