Poultry Flashcards
Class
- Aves
Order
- Galliformes
Family
- Phasianidae
Chicken Genus
- Gallus
Chicken Species
- Gallus gallus
- Gallus gallus domesticus = subspecies
- modern chicken –> thru intensive selection of breeding of chickens in last century
Chicken Chromosomes
- 78
Turkey Genus
- Meleagris
Turkey Species
- Meleagris gallopavo
Turkey Chromosomes
- 82
Muscovy Duck Genus
- Cairina
Muscovy Duck Species
- Cairina moschata
Muscovy Duck Chromosomes
- 80
Global Distribution
- 19B poultry worldwide
Chicken Stats - US
- 9B broilers/yr
- broiler = meat chicken
- 100B eggs/yr
- consume 100 lbs poultry/yr
- consume 300 eggs/yr/capita
Turkey Stats - US
- 238M
- 50% of world’s production - mostly for Thanksgiving
Duck Stats - Worldwide
- 28M worldwide
US Broiler Chickens
- concentrated in Midwest and SE (by the coast in open-sided houses)
- where the feed (grains) is, climate, concentration of processing plants in those areas
US Egg Production
- spread out homogeneously
- eggs are more fragile, perishable
- produce eggs locally where consumer is located
Domestication
- red jungle fowl in 1500 BC in Asia
- turkeys native to N America
- domesticated by Native Americans in 200 BC
Dentition
- no teeth
- chicken have genes that could make teeth, but only make teeth with genetic manipulation
- naturally omnivorous, but on herbivorous feed in production systems
Digestion
- beak → esophagus → crop → proventriculus → gizzard → small intestine → ceca → large intestine → cloaca → vent
Crop
- enlargement of esophagus filled w/ digestive secretions that allows for storage
Crop Milk
- some birds (especially pigeons) have enlargement, produce secretions, mix it w/ foods, and feed back to offspring
- looks like milk, but not really milk
Proventriculus
- acidic
- contains different enzymes
- mixes food w/ acidic environment to break down carbs of grains to simple molecules that travel to rest of GI tract
- site of chemical digestion
Gizzard
- mechanical digestion
- accumulation of grit, gravel, shell material (that may be provided to birds)
- blender – mechanical agitation breaks down digester further
Small Intestine (DJI Sections)
- duodenum (mostly this in poultry), jejunum, ileum
- small intestine less long in poultry because a lot of digestion has already occurred
2 Cecums/Ceca
- junction of small and large intestine
- microbes
- birds on low-fiber diet, so ceca fairly small (smaller than chickens on forage diet bcs microbes have less of a job breaking down fibrous material in low-fiber diet)
- microbes can be source of vitamins
Large Intestine
- relatively short
- not distinguishable sections (rectum and colon) like other animals have
- small large intestine –> not as much water absorption
Cloaca
- shared region between urinary system, digestive tract, and reproductive tract
Vent
- cloaca opens into vent
- green coloration of feces: digester
- white coloration: urine (in the form of uric acid)
- urine high in nitrogen, and uric acid captures that nitrogen and turns white
Chick
- young chicken
Pullet
- young females up until sexual maturity or point of lay
Point of Lay
- time that pullet lays eggs and is sexually competent
- 16 weeks of age (4-5 mo)
Hen
- mature layer
Broilers
- reach market weight by 6-8 weeks
- broilers can be pullets or cockerels
- less than 16 weeks, before point of lay
Typical Hen
- ovulates once daily (1 egg laid per day)
- lays 300 eggs/yr
- tend not to lay as much during winter
Ovulation (Daily)
- ovum released from ovary into infundibulum
- yolk release in infundibulum
- magnum
- isthmus
- uterus thru shell gland
- lay after 23 hours
- incubate
- hens don’t have estrous cycle (they don’t have to carry pregnancy; estrous cycle follows follicle development)
Ovaries
- 1 ovary (left)
- 1 uterus
- 1 oviduct
- uterine horn developed
Infundibulum
- site of fertilization if cock present
- site of yolk release
- yolk sits in infundibulum for 15-17 mins
- ovum surrounded by vitelline membrane
- xanthophyll
- double-yolked egg possible
Vitelline Membrane
- blood spots in eggs
- burst blood vessel in infundibulum during yolk production
- not dangerous
- selected out during egg production for consumers’ sake
Xanthophyll
- pigment in infundibulum
- fat-soluble pigment that accumulates in yolk
- can feed marigold extracts to make yolk more orange
Double-Yolked Egg
- yolk stays in body cavity of infundibulum until next day, then second yolk joins first one and they travel down together
- double-yolked egg = 2-day egg
Magnum
- egg spends 3 hrs to travel 30 cm
- deposition of albumen (egg white)
- albumin rich in protein and water – cushion inside the egg
Isthmus
- surrounding egg w/ eggshell membranes
Shell Gland
- how egg enters uterus
- where egg spends majority of formation time depositing eggshell
- 20 hrs out of 23 used in eggshell formation
- eggshell rich in calcium carbonate (CaCO3)
- calcium comes from hen’s bones, which can regenerate calcium later
Ca Homeostasis
- critical for maintaining Ca levels in the body
- calcium deposited in shell comes from hen’s bones and a bit from diet
- lost Ca needs to be regenerated
Protoporphyrin
- creates brown pigment
- “heme” - part of coloring for blood
Biliverdin Pigment
- mutation that only appeared 500 yrs ago when virus entered chicken and mutated gene
- produces blue eggs
Egg Porosity
- 5-10,000 pores for gas exchange
- chickens don’t have placenta, but eggs have all the same characteristics, just externally
Lay
- after 23 hrs
- ovulation event 30 mins later
- by 3pm (longest part of day) or next day
Incubate
- chickens: 21 days at 100 degrees F (38 degrees C)
- turkeys: 28 days at 99 degrees F
Yolk
- nutrition of developing embryo
- source of antibodies
Antibodies
- collection of immunoglobulin proteins
- mammals: IgG, IgA, IgM
- chickens: IgY
Males
- inseminate female and deposit semen in cloaca
- chicken body temp is 106.5 degrees F
- robust sperm
- sperm can survive 10 days in reproductive tract
- sperm stays in infundibulum and fertilizes multiple eggs over time
- male puberty: 4-5 mo old
Clutch
- hen may lay clutch of 10 eggs that she’ll brood
- sit down and incubate eggs
Capon
- castrated male
- chicken meat that is fattier –> delicacy
- not common because castration is slow and expensive, and testes are internal
Artificial Insemination
- not practical, since penis is w/in cloaca
- commercial production of chicken might use AI with breeding stock and send out progeny
Vent Sexing
- standard
- day old chicks
- need to decide which are female, which are males to be euthanized
- want more effective egg sexing technique before hatching to avoid euthanasia
Feather Sexing
- genetic line that has slow growth of feathers that distinguishes M/F
Coloration/Markings
- might have different colors based on sex
In Ovo Sexing
- genotype tiny bit of DNA from egg and find sex chromosomes
- used in Europe
- being promoted in industry, probably become mainstream in a few yrs
Commercial Hatcheries
- hatch all of the eggs laid in breeding facilities
- 21 days in hatchery: incubating egg, turning it, monitoring it
- day-old chicks shipped out to rearing facilities
Broilers
- classified on bodyweight
- avg retail chicken reaches target weight of 5 lbs after 40-50 d (used to take 2x this long to reach this bodyweight)
Benefits of Faster-Growing Bird
- less feed = more sustainable
- more product for same amount of feed
- can raise 2x chicks over same amount of time
- higher dressing percentage
- why poultry has become more popular globally
Feed Conversion Ratio: Broilers
- 1.5-2 lbs of feed to gain 1 lb of bodyweight in birds
Chicken Dressing Percentage
- (carcass weight)/(live weight)
- 78%
Turkey Dressing Percentage
- 83%
Broiler Sheds
- 40,000+ birds
- biosecurity, temp reg, ventilation, space, feed distribution and water, bedding, stress, handling
Biosecurity
- challenge w/ avian influenza
Temperature
- 72 degrees F
- adjust based on growth state
- younger birds more sensitive
Ventilation
- chicken urine part of manure (uric acid) is high in nitrogen –> ammonia gas
Space
- 1 sq ft of space per adult bird
- overcrowding –> injury, aggression
- no enrichment, but healthy social interactions
Feed Distribution and Water
- high stocking density – need access to feed and water
- feeder spacing (fed in troughs/circular feeders)
- can calculate number of cm needed per animal for feeding
- feeder spacing might increase with age
Bedding
- litter (organic material - shavings, rice hulls, wood chips, etc., depending on geographic location)
- change bedding after harvesting broilers
- litter becomes commodity sold back to farms as fertilizer
Stress
- extremely negative for bird wellbeing and product quality
- need calm, timely handling
Handling
- reduce injury
- used to be badly done, but now there’s more oversight, lower injury rate
- manual catching reqs human labor
- mechanical harvesting: machines w/ rubber fingers put birds onto conveyor belts
Pullets Raised for Laying
- point of lay at 16 weeks
- peak lay at 29 weeks
- ovulation somewhat seasonal (max rate of egg production as photoperiod incr - 1 egg/day)
- as days get shorter, rate of lay decreases and production drops off significantly
Induce Molt
- for reproductive tract to regenerate
- coincide w/ shorter days
- manipulate photoperiod (barns full of lights –> max egg production)
- induce molt w/ feed restriction and/or reduced lighting
- decr egg production, allowing for regeneration of reproductive tract and greater egg yield over time
Housing and Management of Broilers
- temp, air quality, space, ammonia, humidity
Chicken Broiler Facilities
- multiple sheds, esp on E Coast near Delaware
- day old chicks all brought in at once
- 6 broods/yr
- all in/all out apprach
- clean up facilities after each round/harvest
Turkey Shed
- longer growth period
- 2-3 broods/yr
- all in/all out approach
- clean up after each round/harvest
Processing Considerations
- slaughter must be humane (consumer preference/feedback)
- immediacy of euthanasia
- harvested from sheds at night to reduce stress
- immediately taken to processing plants and euthanized
- billions processed each year
Pullets
- point of lay: 16 weeks
- 80 week egg-laying lifespan
- photoperiod regulates rate of lay
- induced molt used to be forced by feed restriction/starvation –> now less common bcs it puts bird in state of stress
- now, induce molt by manipulating nutrients and adjusting photoperiod
- induced molt regenerates reproductive tract and incr egg quality that would otherwise decr as hens aged
- rate of egg laying might decline w/ age
Traditional Housing
- stacked cage system
- multiple birds housed w/in one battery (wire) cage
- benefits:
- can monitor all birds close up, efficient collection of eggs, high stocking density
Prop 2 (CA)
- first ruling where CA public said they wanted to ensure layers could spread their wings
- more space than traditional battery cage
Prop 12 (CA)
- no cages for egg-laying birds after 2022
- also specified that eggs coming into CA had to be produced w/ that stipulation
- led to incr in egg price
- one of the best examples of public influence on animal raising
True Antibiotic Use
- like penicillin
- extensively used in human medicine
- used to be used as blanket meds for broilers especially (birds grow better)
- now all animal industries minimally use antibiotics to limit antibiotic resistance
- objective is not to use them at all (sign of good management and welfare)
- if used, must have withdrawal period so antibiotics are gone from animals’ symptoms and won’t transfer to humans, thereby reducing efficacy of antibiotics
Coccidiosis
- protozoal disease
- protozoa infect gut cells of bird and cysts in bird feces that are eggs
- intensively-housed birds might peck at those feces and get coccidiosis
Coccidiostats
- specifically targeted at coccidiosis
- used as feed additive
- preventative medicine
Vaccinations
- day old chicks vaccinated at hatchery
- vaccine applied as little spot on baby chicks
- when they peck at each other, they ingest it from their friends (quick way of vaccination)
Influenza Viruses
- highly problematic and common in wild and managed birds
- HPAI
- can be vaccinated against
Newcastle Disease
- have been a few outbreaks in CA
- entire flocks have to be culled (using CO2)
- can be spread quickly thru wild birds
- highly pathogenic
- transmitted thru backyard cockfighting
- clamped down on cockfighting to reduce disease incidence
- can be vaccinated against
Marrick’s Disease
- can be vaccinated against
Monopolization of Broiler Industry
- 70% of broiler meats produced comes from 10 companies
- these companies own all different parts of production pipeline:
- chicks in hatchery, feed supply (pricing, transport, etc.), water, slaughterhouse (oversee harvesting and packaging - Purdue and Foster Farms), labor (the company’s vets, trade-qualified ppl who can follow strict biosecurity programs)
- very efficient (economically and production-wise)
Vertical Integration
- grower sheds
- company outsources growth of birds to independent operators
- family farms are contractors to company
- company owns chicks, but family farms have more real estate and potential for individual supervision
Disadvantages of Vertical Integration System
- creates monopoly
- lack of competition means some individual farms may be unable to participate
- monopolies inflate consumer prices
Alternatives to Vertical Integration System
- free-range ops: taken off in CA; expand open space so birds can spread out further
- cage-free ops: in CA; still sheds, but birds on ground and perches instead of cages; egg collection done manually
Feed Conversion
- for broilers: 1.5-2.0
- carcass has high dressing percentage
Byproducts
- fertilizer
- feather meal – potentially fed to other animals, including ruminants