Poultry Industry & Chicken Virus Flashcards
What are the light (egg type) breeds
Single comb white leghorn
What are the heavy (meat type) breeds
Cornish male and white rock female
What are the dual purpose backyard breeds?
Rhode Island Red, Barred Plymouth Rock, White Plymouth Rock, New Hampshire
How would you sex chickens by the feathers?
Long primary feather = female
Short primary feather = male
Pullets raised in pullet houses until ____ weeks of age, and they begin laying at ___ weeks of age
16 weeks old, moved to layer house, 17-18 weeks begin laying
White leghorns produce _____ eggs/hen/year ingesting ___ feed/dozen eggs
220-240 eggs/hen/year
2.9 lb of feed/dozen eggs
Brown egg layers produce ____ eggs/hen/year ingesting ___ feed/dozen eggs
187 eggs/year
3.3 lb of feed/dozen
What is the humane way to put your chicken flock through a molt?
Decrease the day length and give high fiber feed
Goal is a 4lb male broiler chicken. How long does it take to achieve this?
6 weeks old with a feed efficiency of 1.7:1
What are the top two reasons for a chicken to be condemned at slaughter?
Sep/Tox and Airsacculitis
What are the two biggest disease concerns in the duck industry?
Riemerella (Pasteurella) anatipestifer
E. coli septicemia
What are your top two differentials for splenomegaly in chickens?
#1 – Erysipelas #2 – Adenovirus II (HE of turkeys)
Name the 4 diseases associated with Aviadenovirus (group I adenovirus)
Quail bronchitis
Inclusion Body Hepatitis (chickens)
CELO Chicken Embryo Lethal Orphan
Serogroup I Adenovirus of Turkeys
You are given a dead quail to necropsy. The bird is less than 8 weeks of age. It has intranuclear inclusion bodies within the tracheal epithelium, as well as karyomegaly. What is your top differential?
Quail Bronchitis
Aviadenovirus
<8 weeks old
What is very important to remember about Inclusion Body Hepatitis for the exam?
“Egg Transmission” or Vertical Transmission
You are presented with 7 week old chickens that are suffering respiratory problems followed by death. Some are showing a hemorrhagic syndrome with aplastic anemia. There is a 10% drop in egg production. What disease are you most suspicious of?
Inclusion body hepatitis! Aviadenovirus
3-15 wk old chickens
Secondary to immunosuppression
Describe the Avian Encephalomyelitis virus
Aka AE aka Epidemic Tremor
Picornavirus,
Non-enveloped, ssRNA
You are presented with young chickens under 3 weeks of age showing muscle tremors of the head and neck, ataxia, and paralysis. On necropsy, you notice the birds have cataracts, as well as white areas in the muscular layers of the proventriculus, ventriculus, heart and pancreas. What is your top differential?
AE! Avian Encephalomyelitis! Epidemic Tremor!
Tremors + cataracts = AE
Also diagnostic: brown central chromatolysis in brain (remember Newcastle has peripheral chromatolysis)
On a slide from a brain sample from a chicken, you notice brown central chromatolysis. What is your diagnosis?
AE
Avian Encephalomyelitis
Epidemic Tremor
Describe the prevention/ vaccination process for AE
All breeders & laying hens
Prime with MLV and then wing web injection with pox at 8-10 weeks
Water vaccination probably best
Vaccinate layer pullets 4+ weeks prior to moving to layer house
What is the Flu D ELISA?
It’s like a pregnancy test for AI
Acute infection only
Remember IgG’s more efficient with ELISA
IgM more efficient with hemagglutination inhibition / AGID
Describe the AI virus
Orthomyxovirus, Type A
Enveloped, ssRNA
Name the two types of genetic mutation changes
Genetic Drift- gradual shift driven by vaccine pressure
Genetic Shift- overnight change in antigenic structure
A flock has a mass die-out overnight. On necropsy there were cyanotic combs, facial edema, comb blisters, blood in the trachea, esophagus, proventriculous and cecal tonsils. There were hemorrhages on the heart and small intestines. There was a fibrinous airsacculitis present. What is your top differential?
High Path AI
You are presented with a bird that has an irregular iris. What is your first differential?
Marek’s Disease (herpesvirus)
Lymphocytic plasmocytic iridiocyclitis
You are presented with a chicken with cataracts. What is your top differential?
Avian Encephalomyelitis
You are presented with a chicken with a cloudy cornea. What do you suspect is going on?
High concentration of ammonia in the barn.
If you are presented with an emaciated chicken, there are a number of possible causes, but what are your most common?
Marek’s disease and TB (mycobacterium avium)
Describe the Marek’s Disease virus
Aka Range paralysis aka neural lymphomatosis aka skin leucosis
Cell-associated herpes virus (subfam Alphaherpesvirnae, genus mardivirus)
Enveloped dsDNA