What are the precautions for heat treatment of hatching eggs from different flock ages?
The same profile can be used on any flock age. Trials have been done on hatching eggs from young, middle and old flock sources and the same profile works on all three groups. The greatest benefit will be seen on hatching eggs from old flock sources because naturally they have the most early dead embryos. Heat treatment helps to lower the number of early dead embryos by repairing the cells inside the egg during storage period.
Can eggs from the cold room be placed inside incubator without pre-warming?
For multi-stage incubator, setting eggs directly from the cold room will cause the machine to take a little longer to reach set point. If eggs are pre-warmed, the machine will recover quicker. If the machine takes more than 2.5-3.0 hours to recover, there may be a few more early dead embryos. The main issue will be on achieving ideal hatch window. Whenever cold eggs are placed into multi-stage incubator without pre-warming, the temperature inside the incubator will drop and this spreads the hatch window.
For single-stage incubators, there is no need to pre-warm the eggs before placing them inside the incubator. Single-stage incubators typically have a setting of 80F for 4-6 hours to pre-warm eggs before trying to achieve 100.4F.
Pre-warming eggs before setting is a good idea if we have a dedicated room with proper airflow, similar to incubator conditions. It is not recommended to pre-warm eggs if it is done in the hallway in front of the incubators. Pre-warming in front of the incubators will cause the eggs to condensate, which will increase the contamination percentage. Pre-warming in the hallway with poor airflow will not warm the eggs evenly and this will spread the hatch window. Without a proper room for pre-warming, it is best to set eggs from the cold storage room directly into the incubator.
What is the recommended relative humidity percentage set point during heat treatment of eggs?
Humidity should be turned off and the eggs do not have to be turned during heat treatment. The trolleys can be in level position and incubator damper should be closed.
How should eggs of different ages in the same egg storage room be managed?
The ideal setup is to have two or three egg storage rooms that can be set at different temperatures for different egg ages. If there is only one egg storage room, set the temperature for the older eggs in the room. It is still acceptable to store fresher eggs at a colder temperature of at least 15°C and above. Storing colder than 15°C can cause some early dead embryos due to temperature shock when being placed inside the incubator.
How should the efficacy of the heat treatment process be tested?
One of the ways to test efficacy of the heat treatment process is to take a trolley of eggs from the same flock that was laid on the same day and split it down the middle. Half of the trolley is subjected to heat treatment and the other half of the trolley is placed in the egg storage room for 14 days. After 14 days, both sets of eggs are placed into the incubator. Upon hatch, the hatchability and number of first quality chicks from the heat-treated eggs and the non-heat-treated eggs can be compared.
Will heat treatment of eggs shorten the total incubation period of 21 days?
Heat treatment will not shorten the incubation period of 21 days. If a chick is hatched earlier than 21 days or 504 hours, too much heat has been used during the incubation process and this is not optimum for the health of the chick.
When eggs are stored longer than 8 days, incubation time typically has to be added. It is recommended to add 30 minutes per day for eggs stored past 8 days but do not add more than 3 hours total unless needed. For example, if chicks typically hatch in 505 hours, for a 9 days old egg we will need to set the eggs 30 minutes earlier to target 505.5 hours.
Heat treatment will shorten the amount of incubation hours needed for eggs stored longer than 10 days. If it typically takes 510 hours to hatch a chick from an egg that has been stored 10 days, after heat treatment it may only take 508 hours. Therefore it will not shorten the incubation period to less than 21 days, but will make eggs that are stored longer than 10 days hatch a little earlier than the non-heat treated eggs that have been stored for longer than 10 days.
Apart from long storage time, is there any correlation between eggshell thickness and hatchability?
Long storage time reduces hatchability due to the reduction of live cells inside the eggs, ultimately leading to the death of the embryo. Eggshell thickness affects hatchability if the shell is too thin. When the shell is thin, it increases the chance of hairline cracks which increases the risk of contamination and decreases hatchability.
Is there any possibility of thermal shock once the eggs are transferred back to egg storage room after heat treatment?
There should not be any thermal shock as it is best to allow the eggs to cool inside the incubator using a profile first before transferring back to the egg storage room. This will also prevent the warm eggs from warming up the egg storage room too much and causing issues with the eggs that are already in the egg storage room. After heat treatment, allow the eggs 2-3 hours to cool down before placing them back in the egg storage room.
Does long egg storage affect broiler performance?
Typically, when eggs are stored for long periods of time, there is a reduction in hatch of fertile, lower chick quality and an increase in 7-day mortality. Chicks from eggs that have been stored for a long period of time typically do not look as good when they hatch compared to chicks from eggs that have been stored for 3-8 days.
How should heat treatment be applied using a multi-stage incubator?
Heat treatment trials have been carried out in a multi-stage incubator with very good results. Start heat treatment inside a multi-stage incubator with a few eggs and see if it works. The problem with using multi-stage instead of single stage is that multi-stage does not have the cooling capacity to get the eggs below 26°C after treatment. The eggs must be removed from the incubator and placed in the hallway for an hour or so for cooling before taken back to the egg storage room. If the eggs are removed from the incubator and taken back to the egg room immediately, the warm eggs will raise the temperature inside the egg room. This could have a negative impact on the cold eggs that are already in the egg room. It is possible to try with 1,000 eggs and check the results. If they are good, increase to 5,000 eggs and keep increasing. Start with a profile of 95°F for 6 hours, then remove the eggs and leave them in the hallway for an hour or 2 to cool down.
Is heat treatment recommended for the sole purpose of long-term egg storage or can it be applied for all eggs?
It is not recommended to heat treat eggs unless there are plans to store them for 10 days or longer. Heat treatment takes a lot of time, labor and it is not beneficial for eggs that are going to be stored for less than 10 days.
Will there be any benefit to storing eggs at a 45-degree turning angle if required to store more than 10 days?
Storing eggs in the turned position does not give great benefit. Instead, turning the eggs from left to right every 4-6 hours during storage period does give some benefits in terms of hatchability as this keeps the yolk positioned correctly.
What is the difference between heat treatment and pre warming?
Pre warming is where the eggs are heated up to around 80°F (27°C) before placing into the incubator for the start of the incubation cycle. Heat treatment is where the eggs are warmed up to 95°F (35°C) for 6 hours, then cool them down before placing them back into the egg room. Heat treatment is designed to give short periods of incubation during egg storage to keep the cells inside the egg alive. It is designed to improve hatchability and chick quality when storing eggs longer than 10 days.
Are there any alternatives to formaldehyde as a sanitizing agent?
For fumigating eggs at the farm or hatchery storage room, formaldehyde and potassium permanganate or 91% paraformaldehyde prills are the preferred method of egg sanitation. In the hatcher, very good results can be achieved with hydrogen peroxide but the levels needed to match the performance of formalin are very corrosive to any metal in the machine. Certain quaternary products have been tried in the hatcher but with limited results.
What is the best way to clean dirty eggs before setting?
Washing, rubbing, or sanding eggs is not recommended as these practices can very often have the effect of increasing contamination. Small amounts of 3-D material can be scraped off with a small knife and excessively dirty eggs should be culled. Fumigating eggs as soon as they are collected is recommended
What is Cobb's recommended ventilation per 1,000 hatching eggs in the setter and hatcher.
In multi-stage machines, air is at a constant rate of approximately 0.14 m3/minute/1000 eggs and adjusted for carbon dioxide at a maximum of 0.4%. In single stage machines, air flow rates are adjusted according to humidity and egg weight moisture loss. In the hatcher, fresh air supplied to the plenum should be 17 cfm per 1000 eggs (28.7 cubic meters per hour) or according to the manufacturer’s recommendation.
Will early or late hatch chicks have an effect on broiler growth performance?
Inside an individual source flock, the earlier hatching chicks will be from the eggs with the highest level of moisture loss. The later hatching chicks will be from the eggs with the lowest moisture loss. Low moisture loss during incubation will cause a slow draggy hatch and the chicks that hatch last will exhibit poor broiler performance with low weight gains and high mortalities.
Why would the recommended chick weight loss percentage be lower in single stage machines compared to multi-stage machines?
Single stage incubation typically produces a slightly longer and heavier chick because of the high levels of CO2 that can be run in the first 7 days of incubation. Typically, single stage incubation provides a much more consistent environment than multi-stage incubation.
Does eggshell temperature in hatcher have any effect on chick quality?
Yes, it will definitely effect chick quality but eggshell temperature is not nearly as useful in the hatcher compared to in the setter. They tend to vary widely and can be misleading. For example, if there is consistently a temperature above 102F at 12 hours after transfer at 18 days, there may be a need to cautiously lower the hatcher temperature. Otherwise check the cloacal temperature of various chicks multiple times throughout the hatch process at 24, 18, 12, and 6 hours before removing chicks from the hatchers.
What is the acceptable percentage of chicks with wet navels and what does it indicate if the percentage is higher than usual?
Wet navels should be less than 0.5%. Several issues could cause wet navels, and this includes insufficient moisture loss or slightly low temperatures in the hatcher between transfer and hatch.
What causes string navels in chicks?
The most common explanation for string navels is low humidity in the hatcher between transfer and pipping. Target 50% humidity during this period.
What are the differences in moisture loss between single stage and multi-stage machines?
For many years several of the incubation companies have recommended high CO2 levels all the way up to day 10 of incubation. If this is done, the damper on the machine may not open and allow humidity to drop as late as day 10. In high humidity climates, this does not allow enough time to achieve correct moisture loss. Moisture loss should always be prioritized over running high CO2 levels. Many hatcheries will set a minimum damper opening at around day 7 to manually open the damper. This allows the moisture loss needed for good chick quality.
Does embryo mortality affect moisture loss value?
Yes, if fertility is very low or embryo mortality is very high it will make the moisture loss appear lower than it actually is.
Does the sanitizer that is applied to the eggs during in-ovo vaccination affect hatcher temperature or humidity?
The effects of the sanitizer are very minimal. The hatcher profile does not need to be adjusted in any way because the sanitizer dries very quickly.
How can Aspergillus contamination in the hatchery be detected and reduced?
Every room in the hatchery should be monitored with air plates on days with no hatch and after they have been cleaned. Rooms that plate positive for Aspergillus should receive extra cleaning and fogging with a product labeled to kill Aspergillus. All areas of the hatchery should also be fogged on a regular basis. Any wood and paper products in the hatchery should be limited as Aspergillus can grow on these surfaces. Egg storage rooms on the farms should also be checked as they can be the source of Aspergillus in the hatchery.
How can bursting/banger eggs be minimized at hatchery level?
“Banger” or contaminated eggs are most commonly caused at the farm level when bacteria from fecal matter or dirty nesting materials contacts the egg and penetrates the shell membrane. Over cleaning of eggs at the farm will also remove the protective cuticle later from the egg surface. This is a common problem which will increase the percentage of contaminated eggs. Poor egg handling at the hatchery can also exaggerate the problem. Moving eggs from cool egg rooms to warmer environments such as pre-warm areas without proper air flow will cause moisture to condensate on the eggs. This moisture from condensation increases the growth of bacteria and increases the number of contaminated eggs. The percentage of bangers will also increase when eggs get wet due to faulty humidity systems inside or outside the incubator. Good hatchery sanitation is key to limiting the growth of bacteria and the number of contaminated eggs. Egg rooms should be cleaned several times per week and incubators should be cleaned on a regular basis. All rooms in the hatchery should be fogged with a quality disinfectant on a regular basis.
What is the ideal temperature and humidity required for Cobb hatching eggs to achieve good hatchability in single stage machines?
Typically, in single stage incubation the initial temperature at the start of incubation will be approximately 100.3°F with a step down of 0.1 degree F per day for the first three days. After this period, it is critical to check eggshell temperatures (EST) to build the correct profile. There will be a range of EST but it is important to adjust the profile so that there is no temperature below 99.5°F and none above 102.0°F. Humidity is very much tied to the damper opening and CO2 settings. The correct profile also needs to be adjusted so that the moisture loss targets are achieved. The earlier the damper is allowed to open, the more moisture will be removed from the eggs. In most single stage machines, the damper should begin opening by at least day 8 and in some climates by day 6. Relative humidity level for the first 18 days should average between 45 and 50%.
What causes early hatch?
Typically, early hatches are due to extended pre-warming periods, beginning incubation too early or high incubation temperatures. Pre-warming is at most recommended at 8 hours.
How does low hatcher temperature cause small navel buttons?
An embryo needs enough heat during the period between transfer and hatch for the navel to close completely. Low temperature in this period, which is usually below 98.0°F, will cause the navel to close too slowly leaving a small navel button on many chicks.
Why do we see higher incidences of splayed legs or leg weaknesses from young flock sources and how can this be reduced?
Given the perfect incubation condition, the percentage of chicks with splayed legs will typically be higher from younger flock sources due to the relatively smaller chick size. To limit this issue, Cobb does not recommend using eggs below 52 grams for breeding stocks. If there are incorrect incubation conditions such as high or low eggshell temperatures and low moisture loss below 10% on young flock sources, the number of chicks with splayed legs may increase dramatically.
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