Incubation and Hatching Flashcards
(41 cards)
How many days are chickens, turkeys, ducks and geese incubated for?
Chickens - 21 days
Turkeys, ducks, geese - 28 days
What are the components of an unincubated egg?
Air cell Egg shell and Cuticula Thick and Thin albumen Yolk Chalazea Germinal disc
What are the extra-embryonic membranes and their function?
Yolk sac - surrounds egg yolk and secretes enzymes that help digest the egg yolk
Amnion - absorbs shocks
Chorio-allantois - extensive circulatory system that has respiratory, excretory and digestive functions
Describe the three functions of the chorio-allantois.
Respiratory - allows oxygen through the shell, oxygenates blood and eliminates carbon dioxide
Excretory - filters and deposits wastes
Digestive - aids albumen digestion and shell calcium absorption
What are the components of a chicken embryo?
Egg shell Air cell Allantoic fluid Albumen Amniotic liqued Embryo Yolk sac
When does fertilization occur and what occurs the hours after fertilization?
Begins 15 minutes after ovulation of the follicle
5 hours after: first cell division (when egg is through magnus and into the isthmus)
4 hours after that (9h 15m after ovulation): embryo is 256 cells
~26 hours later (during oviposition): 30,000 cells
Describe the difference you would see if you candled a fertile and infertile egg.
infertile egg - rough and spotted yolk with a blastodisc (germinal disc)
fertile egg - has small, circular rings in the yolk, blastodisc develops into blastoderm
Describe what you would see if you cracked open eggs that have been incubated for 1, 2, 3, 4. and 5 days (respectively).
Day 1: tissue development and maybe a spinal cord
Day 2: small blood vessels, modelled yolk and clear area in the middle
Day 3: heart beat and more expanded blood vessels
Day 4: Dark eye and larger area of vascularization
Day 5: Elbows and knees are apparent
When does the beak, comb and feather tracts become visible in an incubated egg?
Day 6: beak
Day 7: comb (and egg tooth)
Day 8: feather tracts
Describe days 9 to 13 of an egg in the incubator.
Day 9: mouth opening apparent
Day 10: Egg tooth prominent
Day 11: Tail feathers apparent
Day 12: Toes formed, feathers more apparent
Day 13: Scales on legs, feathers spread throughout entire body
What occurs in a fertilized egg from day 14 to day 18 in the incubator?
Day 14: Embryo turns head toward large end of egg
Day 15: Gut begins to draw into body cavity
Day 16: Body now completely covered with feathers, albumen mostly used up
Day 17: Head tucks between the legs, amniotic fluid disappears
Day 18: Full sized embryo, head tucks under right wing
When does the amniotic fluid and yolk sac completely disappear (amniotic fluid is used up, yolk sac is drawn into body) during incubation of an egg?
In the hatchery:
Amniotic fluid is completely used up at Day 19
Yolk sac is completely drawn into body cavity at Day 20
When does lung respiration become apparent in an egg?
Day 21 when internal and external pipping begins to occur.
Describe the difference between internal and external pipping
Internal pipping - neck muscles contract and egg tooth punctures air cell, so the bird can begin to breath
External pipping - more deliberate pecking until chick is outside of egg shell (at day 21)
What eggs should be avoided during hatching egg selection?
Blood stained Cracked Dirty Elongated Rounded Toe punched Wrinkled Small Double Yolked Floor eggs
What influences the temperature a farmer would store eggs at?
Time the eggs will be stored for
- Only a few days - keep it warmer
- Up to 9 days (NEVER more than 9) - keep it colder
What are the consequences of prolonged egg storage?
- Each day of storage adds up to 1 hour of incubation time
- Each day of storage after 6 days reduces the hatchability by 0.5 to 1.5%
- Chick quality reduces after 15 days of storage (weak, wet premature chicks)
What are the incubation requirements every farmer should attempt to achieve?
- optimum temperature
- optimum humidity
- adequate ventilation (good concentration of O2 and CO2)
- regular turning of eggs
Describe the changes in temperature an egg undergoes from the hen’s body to the setter machine
Hen’s Body - 40-41C
Hen House - 24-29C
On Farm Egg Room - 21-25C (depending on if the eggs are staying on farm or being transported to a hatchery)
Egg Transportation Truck - 20-23C
Hatchery Egg Room - 19-21C
Preheating Area - 24-27C (not regularly used)
Setter Machine - 37.5-37.8C
When do eggs begin to release heat when they are incubating?
Around Day 4
How many days are the eggs supposed to be in an incubator for?
18 days
Describe the pros and cons of a multi-stage incubator.
Pros
* heat recovery system recycles heat by using the oldest eggs to heat up the newest eggs
Cons
* no cooling system (older ones could end up producing too much heat for the younger ones)
* biosecurity issues as it isn’t cleaned often
* Exploded egg could contaminate at least 2 weeks worth of eggs
Why would a farmer be more successful if they used a single stage incubator? Why don’t they use them?
They can heat and cool the eggs to exactly the temperature required, energy efficient and have good biosecurity. They aren’t used because it is a new technology, it is hard to figure out how to use them, and new installations would be required (time and money consuming).
By day 17, what is the expected change in weight in an incubated egg?
About 12% weight LOSS.
