Care of Hatching Eggs
Objective
To keep the embryo and eggs contents in the best possible condition for good hatch ability and chick Quality
Principle
Eggs must be keep in clean condition, and at the correct temperature and humidity to achieve the best hatch ability.To achieve this, satisfactory procedure for collection, disinfection, cooling, storage, and incubation of the eggs should be in place, and each process should be carried out so that embryonic development is not compromised.
Fertilization take place at the top of the oviduct shortly after the yolk is released from the ovary. The yolk then passed down the oviduct. as it dose so, the outer layer of the eggs are laid down and the fertilization germinal disc grows and develops. By the time the egg is laid, it contained a germinal disc that has been grown for 24 hrs as they farmed around it,
After the egg is laid it must be be cooled to stop any further development until the egg is set at the hatchery
The care given to hatching eggs has to meet the needs of these dormant (but living) embryo. Fluctuating egg store temperature can cause stop the growth start of the germinal disc which will reduce the hatchability.
The Egg's Protection System.
The egg provides a multi-layered protection system of protection from microbial contamination.
The cuticle,egg shell, shell membrane, and some of the proteins in the albumen act as either physical or chemical barriers to to prevent microbes gaining access to,and growing in, the eggs contents.
Example of bacterial penetration that can
occur immediately after laying through the
pores of dirty eggs shell.
The photograph shows the inner egg shell
surface`of a soiled egg
Key Points
- Eggs should be maintain in a clean state between lay and packing.
- Methods used to remove surface dirt should be gentle.
- So as not damage the cuticle,or block the egg shell pore.
- Condensation on the egg surface should be avoided as it can leads to contamination.
Best Practice for Care of Hatching Eggs
Egg Collection
- Manage flock to minimize the number of eggs laid on the floor.
- Keep the inside of the nests and any collection belts free of litters droppings.
- Collects net eggs a minimum of 4 time a day, adjusting the extra timing so that no more than 30% of eggs fall in any one collection .
- The majority of the eggs laid on morning and collection interval should be managed accordingly.
- The nest and eggs collection belt should be cleared in the end of the working day to minimize the number of eggs left over night.
- Collect the floor eggs separately.
- Monitor the number of floor and dirty eggs,and adjust management factors to minimize them.
Eggs Packing and Selection
- Select and pack the eggs immediately after each collection.
- Reject small, cracked or damaged eggs, eggs with gross shell abnormalities, double-yolk eggs, soft shelled eggs and any egg which are more than 25% covered with dirt or dropping.
- Avoid wet egg disinfection method-fumigation with formaldehyde.
- If eggs are to be boxed, they should be cooled to egg store temperature prior to boxing.
- Eggs or trolleys should not be wrapped in plastic until they have to cooled eggs store temperature.
Eggs Disinfection
Fumigation with formaldehyde remains the most effective method for disinfecting the shell surface of hatching egg. If provided fumigation performs excellently, it achieves excellent kill rates of micro organism on the shell surface without wetting the shell, damaging the cuticle, or without damaging the embryo inside the egg. Many different chemicals and application methods have been investigated as alter natives to formaldehyde fumigation. none have proves to be as effective.
- Formaldehyde fumigation should always be carried out using the appropriate safety and application.
- Fumigate the eggs with formaldehyde at least once before they leave the farm.
- Make sure that the eggs are well separated on plastic bags or setter tray
- Ensure the fumigation room is well sealed during the fumigation and allow at least 20 minutes for the gas to circulate after it has been generated
- Heat 10 gm para-formaldehyde or a mixture of 43 ml formalin and 21 gram potassium permanganate per cubic meter of fumigation room.
- Ensure room temperature is a minimum of 24 C or (75.2 F) and humidity minimum of 65%
- Make sure that all gas is completely exhausted from the room before workers re-enter to move the eggs.
Cleaning of soiled eggs
Any surface dirt is not extensive, It can be removed by gently flicking the dirt off with a finger or nail, or for soft droppings, by gently wiping off with a clean paper towel.Care should be taken not to contaminate the clean parts of egg. The egg then should be disinfected and sent to the hatchery clearly marked as dirty.
The washing of the hatching eggs should not be practiced. But under some condition, washing eggs may be unavoidable.If washing is necessary apply the following points.
- Use a washer which spray the eggs with warmed disinfectant solution, rather than one which relies on the eggs being immersed in the solution.
- Wash water should be 41 C this will ensure that the water is always warmer than the eggs
- Make sure that the disinfectant concentration does not fall below the recommended minimum effective concentration level and the washer solution should be regularly replaced.
- Allow the eggs to dry before they are cooled in the egg store.
- Washed eggs still needed to be fumigate, but this should not be done until the eggs become dry.
Egg storage conditions
After the laying egg should be cooled so that cellular growth of the embryo is paused.Ideally, hatching eggs should all be set with in 7 days of lay. Store longer than 7 days will results a loss of hatch ability due to embryonic cell death and decline in internal quality, especially albumin quality.
Temperature
- Once the eggs are cold keep the temperature constant, Watch for variable storage temperature through the day
- It is important to coordinate the those used in transportation and storage at the hatchery. This will avoid fluctuating temperature and condensation.
- Storage temperature needs to be set at a level that will maintain internal egg quality and keep the dormant embryo alive
- keep the farm store 2 centigrade warmer than the hatchery store, with the truck temperature intermediate between them. This will help to avoid condensation forming on the eggs.
- Do not blow the cooler or heater fans towards eggs.
Relationship between length of egg storage and
Temperature of the egg store
Stored
Periods
(Days)
|
Temperature of storage
C0 --F0
|
1-3
|
20-23 (68-73)
|
4-7
|
15-18 (59-64)
|
>7
|
12-15 (54-59)
|
>13
|
12
(54(
|
*Humidity should be between 75 to 80%
Humidity
- The humidity of eggs store should be between 75-80% (RH),to prevent the eggs losing too much moisture during storage.
- If cold eggs are moved into a warm humid atmosphere, condensation will form on the egg surface.
- Make sure that the water in the humidifier is clean and that the spray nozzles are maintained properly so that they produce a fine mist of water and not the large droplets.
Condensation on the surface of the eggs |
Key Points
- Nest cleanliness and regular/frequent egg collection are extremely important. Any egg laid onto dirt or droppings can easily becomes contaminated.
- There will be microbes even on the shells of clean hatching eggs. Unless there is effective disinfection of the shell surface before eggs arrived at the hatchery, they present a risk to hatchery hygiene and embryo survival and health.
- Formaldehyde fumigation is the best method for disinfecting egg shells. insure that temperature, humidity and air circulation are appropriate for effective fumigation.
- Follow the safety procedures.
- Monitor and record egg washing procedures.
- On the farm, storage temperature should be adjusted for oldest eggs, fresh eggs will hatch normally if kept at lower temperatures, whereas the hatch of longer stored eggs will suffer if kept too warm
- If there is condensation on the eggs, do not fumigate them and do not put them into the cooler untill they have dried.
Problems resulting in rots and banger
If the hatchery is observing an excessive numbers of rots and banger, check the following:
- The numbers and severity of dirty eggs being produced.Make sure nests and collection belts are checked regularly and cleaned immediately if a problem is spotted.
- Floor eggs are not washed and them mixed with nest eggs.
- The eggs are not collected or packed into dirty trays.
- The shell quality is normal for age of the flock. Shell quality can be damaged by inappropriate feed or certain respiratory diseases.
- Eggs washing and disinfectant media are 41 C.
- Washed eggs are not mixed with clean eggs.
- Wet eggs are not placed in the store.
- If the humidifier has a reservoir, replace it with one that off the main supply,
- Flush the water pipes if the humidifier has not been used for a while.
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