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How broiler chickens compare to other domestic feed animals
The most favorable feed conversion ratio (1.8, better than cattle, sheep, swine, and turkeys
- Specialized facilities designed to hatch fertilized eggs received from breeder farms
- placed in incubators and carefully monitored for humidity and temperature
Top consumption and production
- Americans consume the most chicken
- Mexicans consume the most eggs
- Georgia, Arkansas, Alabama, NC, Mississippi, Texas produce the most chickens
three biggest broiler companies
- Pilgrim’s Pride
- Perdue Farms Inc
- 46.5% of industry
- Hazard Analysis and Critical Control Points
- protocol of cleanliness and safety by plants, restaurants and food service industries
Top producers and consumers of eggs
- US: 263.3 eggs/person
- Mexico: 335 eggs/person
- Production states: Iowa, Ohio, Indiana, Pennsylvania, California
- Tope 10 companies have 48% of industry.
- Made by chickens with brown ear lobes.
- Protoporphyrin responsible, nutritionally the same
Broiler breeds (3)
- Cornish Hen
- Cornish Cross
- White Plymouth Rock
Layer breeds (2)
- Small bodied and selected for high egg production
- White leghorns: mediterranean class, lay white eggs. Basis of commercial industry.
- Rhode Island Red: American class. Production bred strains. Brown eggs
FDA rule for egg laying farms
- Prevention of Salmonella in shell eggs during production, storage and transport
- producers with 3,000 hens or more
- Salmonella testing, biosecurity
Turkey industry numbers
- 228 million turkeys raised in US
- $805 million export (14%)
- 5 export markets: Mexico, china, Hong Kong, Canada, Dominican Republic
commercial varieties of turkeys
- broad-breasted bronze
- broad-breasted white
- 35-42lbs in 16-19 lbs
- Butterball #1
- Minnesota, NC, Arkansas, Indiana, Missouri etc
turkey production houses
- AI every 3 weeks
- Brooder barn/house 0-5wks
- Grower/finisher house after
Common viral diseases of chickens (6)
- Marek’s Disease
- Infectious Bronchitis
- Avian Influenza
- Infectious Laryngotracheitis
- Fowl Pox
Common bacterial diseases in chickens (4)
- E coli
- pasteurella (backyard chickens)
Nutritional diseases of chickens
- Ca/Vit D3
- Backyard: A, E, B
Parasitic diseases of chickens (3, 4)
- External (backyard): lice, mites, ticks
- internal: nematodes (backyard), cestodes (backyard), coccidia, protozoa
- Tumor causing disease
- caused by Herpesvirus
- chicks infected by ingestion or inhalation of virus
- transmission from infected premises
- dander from feather follicles infectious for more than 1 year
- Illness between 10-20 weeks. Mortality 5-50% in unvax
- signs: weight loss. Paralysis (classic form), tumors in multiple organs. Tumors of feather follicles, irregular pupil and discolored iris. Look for swollen nerves sciatic.
- Dx: signs (paralysis), gross lesions, histo, PCR***, immunohistochem with virus-specific abs
- tx: control is vax at 1d!
Lymphoid leukosis virus
- Neoplastic dz in chickens older than 25wks
- transmitted vertically from egg or horizontal exposure at hatching
- signs: pale, listless, thin, prominent keel. Enlarged abdomen (huge liver, tumors of internal organs (liver, spleen, kidneys, bursa. NEVER NERVES)
- Etiologies agent: Avian leukosis virus
- tx: no tx. Breed from leukosis-free breeders, test frequently.
Poultry resp diseases
- infectious bronchitis
- avian influenza
- infectious laryngotracheitis
- fowl pox (wet form, dry is skin)
Newcastle disease and infectious bronchitis
- VERY SIMILAR
- Newcastle: paramyxovirus affecting chickens and turkeys. Neuro form, exotic is high mortality
- IBV: coronavirus affecting chickens only
- signs: resp (labored breathing, wheezing, gurgling) and reproduction, drop in egg production. Lacrimation, sinusitis, dyspnea, depression, mucoid oral and tracheal discharge. Thin shelled eggs or no shell
- Spread: VERY contagious through droppings and resp discharge
- Tx: vax! No tx
- Zoo: conjunctivitis in humans from Newcastle
- Extremely contagious orthomyxovirus
- Lots of combinations, type A in humans, swine, avian, equine etc. MIX!
- wild birds esp waterfowl, asymptomatic (natural reservoir). Transmission: airborne, direct contact. Infected shed in saliva, nasal secretions, feces.
- types: low path = mild illness and drop in egg production, some can switch to high. High path = severe, high mortality.
- Signs: resp disease, drop in egg production, swelling of head and neck, swollen sinuses, comb cyanosis.
- Dx: Lab for subtype.
- Zoo: HUMAN HEALTH SIGNIFICANCE. Some have 50% mortality
- Tx: none.
- Two types: wet and dry
- specific for chickens
- transmission by direct contact with infected birds or mosquitos.
- VAX - only control. Immune for life.
- Dry: Yellow/brown scabs on non-feathered
- wet: yellow, caseous lesions in mouth, esophagus, trachea. Like ILT.
Infectious Laryngotraceheitis (ILT)
- Resp spread (or fomites).
- severe resp distress from clotted blood and caseous exudate.
- E. coli is main or secondary pathogen.
- Air sacculitis, pericarditis, ophalitis (egg sac), peritonitis (includes yolks), salpingitis, synovitis
- tx: abx rarely, but terramycin or duramycin in water, 24h w/d
- salmonella pullorum: host specific, vertical in chicks and turkeys. White diarrhea in first week. Eliminated in commercial (exotic)
- paratyphoid salmonella: not host specific (not just poultry). Signs in young. Drowsy, eyes closed, ruffled feathers, cold, diarrhea, dehydration, pasty vent, inflamm of repro organs, liver, heart
- prevent with biosecurity, commercial vax. Rarely abx.
- tx if abx: terramycin or duramycin in water, 24h w/d
- Gallisepticum and synoviae
- Turkeys and broilers
- infecious sinusitis in turkeys
- hard to control
- Vertical - hatchery infections, exposure to infected birds or fomites/equipment
- signs: conjunctivitis, infraorbital swelling, eyelids swollen shut, synovitis.
- Tx: tylosin in water
- usu where feed is made not bought
- vitamins unstable and destroyed by sun
- rickets: Ca and vit D def.
- Oocysts in droppings, horizontal spread to others in pen
- Eimeria - 9 types in chx
- worse in wet and humid, outbreaks in spring/summer
- mgmt with coccidiostats in feed and cleaning up litter (dry!)
- tx: coccidiostats, amprolium, sulfa drugs (not for layers)
Sampling for chicken viral resp diseases
- Choanal, tracheal or oropharyngeal swabs for chickens and turkeys, cloacal swabs for ducks.
- Place in Viral Transport Media (VTM)
- or submit trachea, lungs, cecal tonsils, kidneys and spleen in ziplock for VI or PCR
- Infectious disease of poultry characterized by acute septicemia with high morbidity and mortality or a chronic, localized form of the disease. Swollen, ulcerated lesions on hairless/head
- pasteurella multocida (gram neg bi-polar staining bacillus)
- tx: sulfa drugs and abx like pencillin, tetracycline, streptomycin (no sulfas in layers). Move to clean premises to slow. Early marketing if you can’t control it.
Histomoniasis (blackhead) = histomonas meleagridis
- esp pathogenic for turkeys under 3mo
- ingestion of contaminated feces or earthworms containing cecal worm (which carries it)
- signs: sulfur-colored diarrhea and pathognomonic “target” lesions in liver, ceca. High mortality in turkeys.
- Caseous cores in enlarged cecum.
Lice - menacanthus,stamineus,menopon gallinae
- Species specific
- head louse (head and neck), body louse (vent, breast, head), shaft louse (feather shaft), wing louse (feather barbules)
- signs: restless, constant preening and scratching,poor weight gain and egg production, feather loss and irritation around vent, tail and breast. Severe can cause mortality esp in chicks.
- Grossly visible esp during the day
- eggs are white cemented clumps around base of feather shaft like salt or sugar.
- tx: carbaryl (Sevin) spray or dust, malathion spray, permethrin spray or dust. q2wks, inspect monthly.
- Lots of time OFF bird, spread by fomites. Come out at night, hide during day.
- Wild birds involved.
- Northern fowl mite, chicken mite (red mite), scaly leg mite - ivermectin or coat leg with petroleum jelly or sulfur to suffocate. Brush kerosine + linseed oil on legs and perches to prevent.
- signs in heavy infestation: poor growth, reduced egg production and fertility
- Lesions: erosion of intestinal lining and severe inflammation +/- hemorrhage. Adults in intestinal tract with heavy infestation.
cecal worms - heterakis gallinae
- doesn’t affect health of bird
- but transmits histomonas meleagridis
- Eggs are viable for a long time
- Ascaridia Galli most common
- chickens and turkeys
- adults seen during necropsy or occasionally found in eggs
- eggs for 2y in lab or 1y outside.
- Extra-label tx
we usually see vitamin deficiencies in chickens because
People try to make their own feed
- Local injury to integumentary of avian foot leads to scab formation and inflammation of SQ tissues with staph infection
- sequelae includes tendonitis and osteomyelitis
- trauma and poor litter conditions predispose.
- Tx: Clinda, doxy, or lincomycin, or amoxi. Remove pus/caseous material, wash and disinfect with iodine. Put a pad over, then put a cast or cut up tennis ball over that to prevent pressure. Stay out of water (ducks). Abx until healed. Fix mgmt.
causes of swollen abdomen in chickens
- fat deposition
- cystic oviduct
- impacted oviduct
ascites or pulmonary hypertension syndrome
- abdominal distension, reluctance to move, resp distress
- lesions = hypertrophy and dilation of R ventricle with or without accumulation of fluid in coelomic cavity. Or hydropericardium, fibrin clots in ascetic fluid and fibrotic liver.
- Recommend feed restriction programs (fat!)
- sporadic in older hens, can increase in outbreaks involving salmonella, mycoplasma, pasteurella and E. coli
- left abdominal lair sac or coelomic cavity can extend into oviduct.
- ascending can occur with cloacal injuries (cannibalism)
- mucosal folds of viaduct become edematous early, adherent fibrinopurulent exudate accumulates.
- Ovaduct stretches due to masses of laminated cheesy exudate, ovduct non-functional, ovaries atrophy.
- Emaciation, diarrhea, death