Behavioral disorders & mycoses in poultry Flashcards
What is stereotypy in poultry?
A stereotypy is a term for a group of behaviors that are repetitive, morphologically identical and which possess no obvious goal or function.
Established stereotypy cannot be eliminated.
Can be reduced by providing stimulation.
Describe cannibalism in poultry.
The term includes:
breaking and eating eggs
plucking and eating feathers
pecking other birds (also to death)
Is caused by:
hereditary factors
unsuitable environmental and feeding factors
infect. diseases and endo/ectoparasites
Also possible to not find a clear cause for the cannibalism.
Breaking and eating eggs is a type of poultry cannibalism behavior commonly seen in what type of husbandry-set up?
alternative/deep-litter systems
May be due to a lack of nesting areas/space or an absence of minerals/protein.
Plucking and pecking typically preludes
full on cannibalism
Can include pecking the cloaca causing prolapse and/or salpingitis.
The most common cause of death of laying hens is?
cloacal pecking type cannibalism
Prevention of cannibalism.
Reduce pop. density and stress, add feeding troughs and nests.
Separate and cull known cannibals.
Cut chick beaks.
Optimize daylight length and intensity using red light.
Dry bedding, avoid drafts.
etc.
What is hysteria in reference to poultry husbandry?
Hysteria is considered to be the strongest expression form of fear. Panic attacks with flying.
Can be caused by sudden noises, humans, predators, overcrowding, even vit B deficiency and too high temp. too dry air.
Describe broodiness in poultry.
In all production birds (except quails).
Chickens that lay brown eggs and kept on deep litter. (rare in white gg layers)
Broodiness is hereditary. Environmental and housing conditions contribute to its development.
Causes great economical losses (I guess they don’t lay eggs if their sitting on a batch? and 1 broody birds may trigger many others to be broody as well?).
How to wean birds from broodiness?
1 day of isolation helps in 80% of chicken cases. Laying begins again in 8-14 days.
Some may do longer isolation periods.
Turkey broodiness passes within 4 days on average.
Describe post-mating phallus pecking.
More common in muscovy ducks and geese do not have this problem.
Occurrence should not exceed 1%.
It takes 0.5-1 min for the phallus to retract after mating. During this stage, other males may peck and injure the phallus. May lead to prolapse. Often, the pecking injury means the bird is no longer usable for breeding.
Causes of post-mating phallus pecking.
Overcrowding
No possibility to mate in water (which is most natural for waterfowl).
The phallus also retracts more quickly in water.
Prevention of post-mating phallus pecking.
Create water-mating possibility
Make smaller breeding groups
Provide larger floor space per bird
Describe phallus prolapse in birds.
Seen in male waterfowl and ostriches.
SIGNS:
* SLUGGISHNESS, NOT EATING OR COMMUNICATING, HIDING/KEEPING AWAY, ABNORMAL BEHAVIOUR.
CAUSES:
* MECHANICAL DAMAGE, INFECTION, HYPERSEXUALITY, IMMUNOSUPPRESSION, TUMOURS, SUDDEN CHANGES IN KEEPING, FROSTBITE ETC.
TREATMENT:
* CULLING
* IN PET BIRDS: PHALLUS REPLACEMENT, SURGERY (REMOVAL OF PHALLUS)
Describe aspergillosis.
Mostly caused by Aspergillus spp. fungi/mold, which is one of the 4 most common fungal species.
Is found everywhere but most in warm and poorly ventilated environments.
Able to live at 37-50’C.
Not a zoonosis but allergic, immunodeficient, pregnant and diabetic people are sensitive to molds from this family.
Describe Aspergillus infection.
By inhalation of spores.
Small spores reach bird air sacs. Perforation of air sacs spread the organism as well as blood.
Granulomatous or infiltrative form.
Not usual in healthy birds.
Turkeys are more sensitive than chickens.
Predisposing factors:
warm and humid environment, poor ventilation and sanitation, bird age (acute in young, chronic in old), corticoid use, lead poisoning etc.
Acute aspergillosis is typical to
young birds
High lethality (75%)
Mortality begins after 3-5 days of infection.
Characterized by Pneumonia, inflammation of the lungs and air sacs.
Aspergillosis in older birds is typically
chronic/systemic
Has low morbidity and mortality.
Systemic granuloma formation.
Clinical signs of acute aspergillosis respiratory disease:
open beak breathing
voice changes
regurgitation
lung and air sac damage
loss or lack of appetite
pyrexia
cyanosis
polydipsia
diarrhea
sudden deaths
Clinical signs of chronic, granulomatous aspergillosis systemic disease:
conjunctivitis
hepatitis
diarrhea
infection and death of embryos
neuro signs
decline in production
necrotic granulomatous dermatitis
osteomyelitis
ophthalmia (ocular inflammation)
encephalitis
Diagnosis of aspergillosis.
At necropsy, caseous nodules in the lungs and air sacs, sometimes other organs.
Microscopic examination should yield fungus find in fresh tissue samples.
Cultivation is difficult.
Aspergillosis should be suspected if respiratory disease does not respond to antimicrobial therapy!
Treatment and prevention of aspergillosis.
Rarely treated in production birds.
Antifungals topically or systemically - itraconazole, amphotericin-B.
Treatment very long; weeks to months. Prognosis guarded.
Prevention is key:
adequate ventilation, hygiene, feed control, vaccination etc.
Disinfection should use products that are antifungal such as formaldehyde.
Describe thrush or candidiasis.
Caused by yeast Candida albicans among other candida spp.
Part of normal microflora in both animals and humans and some plants as well.
All bird species are susceptible; most often in chicks under 3 weeks.
Spreads via direct contact, feces and resp. secretions.
Most sensitive are allergic-, pregnant, immunodeficient and diabetic people.
Signs of candidiasis in poultry.
variable and non-specific
lethargy, drowsiness
loss of appetite, regurgitation
watery brown stools
rough plumage, stunted growth
sour smell from mouth
prolonged crop emptying time
white plaque in mouth
Post mortem Signs of candidiasis in poultry.
Most organs do not have perceptible damage.
Possible:
spotted liver
thickening of crop wall mucosa
white-yellow plaque on GI tract mucosa
the mucosa can also be thickened and wrinkled
Treatment of candidiasis in poultry.
+ prevention
very mild or early on:
correct diet, support immune system
severe illness: empty and wash crop,
fluid therapy, antifungal drugs, support immune system
Prevention:
avoid prolonged & excessive use of ABs, good hygiene, balanced diet, administration of apple cider vinegar or copper sulfate
Bird species most sensitive to mycotoxins?
Most susceptible: turkey and duck chicks, then geese.
What causes the most damages top poultry farming?
mycotoxins (harmful compounds produced by molds)
all mycotoxins affect the metabolism of vitamin D
mycotoxins in bird meat and eggs can cause carcinogenic metabolites in humans and thus tumors.
How are mycotoxins formed?
during improper storage of cereals/grains especially when moisture content is high.
chemical factors: carbon dioxide, oxygen, pesticides and fungicides contribute.
biological: cereal variety, insects, spores, grain sensitivity to molds.
When humidity is less than how much, molds don’t multiply.
less then 13%
they multiply happily at 20-25% humidity.
Name some of the most important mycotoxins.
aflatoxins
fumonisins
vomitoxin
ochratoxin A
T2 toxin
zearalenone
Describe aflatoxins.
Are produced by aspergillus spp.
Are the most common type. Common in peanuts, cereals, fruit seeds.
Animal feeds are contaminated when stored in humid, warm environment, or are contaminated when still in the field.
Are teratogenic and carcinogenic.
Metabolized in the liver.
Describe ochratoxins.
These are the most toxin mycotoxins to birds specifically.
Found in barley, corn wheat oats rye peanuts.
Produced by aspergillus and penicillium spp.
Primarily causes renal impairment, secondary damage to liver, bone marrow etc.
Describe fusariotoxins.
Fusarium spp. are soil fungi and they produce various toxins.
Depends on the toxin how it affects the bird.
Symptoms appear 1-5 days after ingestion of toxin.
Describe fumonisins.
Mycotoxins produced by Fusarium and Aspergillus spp.
Common in corn.
Birds are not usually very sensitive.
Cause damage to the CNS and parenchymal organs; mostly liver and kidneys.
diagnosis, treatment and prevention of mycotoxicosis in poultry
Diagnosis:
history, signs, necropsy, feed samples, chromatographic tests etc.
No treatment.
Prevention:
don’t feed contaminated feeds duh
Wash and disinfect storage places.
Administer vitamins and minerals, especially selenium, to aid birds in recovery if exposed to mycotoxins.
How do you prevent mycotoxins from forming in feed grains?
post-harvest drying of cereals
proper storage
proper transport temp. and humidity
destroy contaminated material
use mycotoxin binders
How can mycotoxins be neutralised?
organic acids are effective
absorbent feed additives
esterified pectin
heating works on some toxins
