Determining incubation profiles
Incubators very precisely ?imitate mother nature. If all the conditions are correct, ?the highest output and chick ?quality can be expected. ?That demands permanent monitoring and determining correct incubation profiles.
By Scott Martin, hatchery specialist, Cobb-Vantress World Technical Support Team, USA
The first thing we need to keep in mind is that everything we do in our incubation influences broiler performance. We obviously want to influence incubation in a positive manner. It does not take much of a mishap in incubation to decrease broiler performance. We try to correct machine issues and calibrations, but typically the damage has already occurred. Therefore, it is important to understand what we are incubating and what profiles will be conducive to good broiler performance.
Genetic progress
Figure 1 (see next page) shows the evolution of genetic progress. It shows how much the bird has changed over time. This progress comes at a cost. So it is more important now than ever to keep incubators calibrated, run the correct profiles and understand the incubation process thoroughly.
If we ran an incorrect profile, it could cost a company two points in feed conversion. At a one million bird per week operation with a feed cost of $332 per ton, these two points would cost $858,000 per year. Whether you have single stage or multi stage incubators, it is important to run the proper profiles.
Scott Martin:
“The more we know about incubation and embryonic development, the easier it will be to determine and manage profiles”.
Three key areas
There are three key areas that need to be under control before profiles become relevant. These are egg holding, incubation management and embryo diagnosis.
Egg holding is important in that we hold eggs properly before incubation. When done correctly, the incubator has the chance to run at its full potential.
Incubation management includes proper calibration and calibration consists of temperatures correctly displayed and matched with their probes, seals and gaskets in place and in good condition, correct turning, fans providing required cubic feet per minute, seasonally adjusted chiller temperature and the proper climate around the incubator. The chiller needs to be at the right temperature. A common problem is that the chiller temperature is set during the warmer seasons but then not readjusted for the cooler seasons. This causes the incubators to cycle improperly. The temperature gauge is usually out of sight and therefore out of mind. Give yourself a reminder. Another area is improper seals throughout the incubator. Improper seals do not allow the necessary air flow or heat transfer in the machines and therefore will disrupt profile. Additionally, they will create microclimates which will not only affect the hatch but will affect the hatch window causing chick quality issues. Turning needs to be at its best at all times. Improper turning will also cause the micro climates. Embryo diagnosis needs to be performed on every incubator in your operation. This is a great management tool because it indicates where opportunities lie and aids in identifying where to focus efforts. Many times we chase the wrong thing and as a result performance does not improve.
Preventive maintenance
Preventive maintenance is the most important programme inside a hatchery. It is the most economical maintenance you can provide for your hatchery. Note the word preventive! Reactive maintenance is extremely costly. The bottom line is to confirm what you think you have is what you have.
We often misuse incubators by not having correct ventilation around them. A good environment requires temperature, pressure and humidity control. These need to be maintained just like the incubators. If these are not correct the incubators will not cycle correctly.
During embryo diagnosis, we are checking certain flocks and certain incubators. It is important to track the following three references: hatch %, hatch of fertile % and fertility % (see Figure 3). Most of all we are looking for trends. Remember to take flock age and egg age into consideration. As eggs age, their hatchability decreases. As flocks age, from young to prime to old, their hatchability changes. Therefore, these need to be considered when setting up profiles.
Be consistent
It is good to score baby chicks by incubator. You might find that one incubator produces more navel issues than others. This monitoring, along with corrective actions, can save you from further performance loss. Also, it is important to take temperatures of the baby chicks as they hatch. This will indicate whether our incubation process is running properly. Programmes, from setting to transfer to pull, are important too. Be consistent about when you set and transfer eggs. Adjust set times only for egg age, fluctuations in embryonic temperatures and skipped sets. The total incubation target time is 504 hours. There is nothing wrong with adding a few hours but do so carefully and make it part of your hatchery programme in order to not negatively impact broiler performance. If we set up programmes to pull at 506 hours (that is when the pull should occur) – don’t pull at 512 hours. If variation occurs then we are holding chicks longer than the profile calls for and something is wrong with incubation.
There must be a separate profile for when single stage incubators are not full or for a skip set in multi stage incubators. Incubators are not designed for less than a full load. So a change in temperature profile and in set times are needed to manage properly.
Things to remember
There are some things to remember depending on what type of incubators you have. On a multi stage operation your setters are multi stage but your hatcher is single stage. On a single stage operation the setter and hatcher are both single stage. Single stage is most forgiving if managed correctly. Here are five things to consider on managing your profile: breed, flock age, egg age, fertility and incubator egg load. Multi stage requires more attention due to the different embryonic ages. Single stage holds the same embryonic age.
On a multi stage profile, the setters are programmed at one consistent temperature. When the eggs are moved into the hatchers (which is single stage because it holds one embryonic age), the temperature can be stepped down to prevent the chicks from getting hot. The young embryos in the setter rely on heat transferred from the older embryos. In the hatcher, it is important to run a step programme to keep the birds comfortable. The target internal chick temperature is 104˚F. The key is monitoring chick temperatures from pre-pull through to pull.
On a single stage profile, the setters have controlled temperatures starting on day one. Your highest heat is on day one and decreases as the embryos age. CO2 levels are high in the beginning and fall until transfer time. Hatchers are run exactly as the multi stage profile described above.
Multi stage profile examples
If you mix flock ages, for an average flock age of 45 weeks, the setter temperature might be set at 98.8˚F. But if you segregate flocks and have only a 29 week old average, you need a different set point. You cannot run the same temperature profile when you have two different sets of flock ages in a machine. Therefore we have to determine what temperature profile we are going to choose for the 29 week old flock. This has to be constantly managed and is an important consideration for an incubator profile.
If you choose to mix then it is important to do the best we can with what we have. Figure 4 shows how to mix flocks inside a multi stage incubator. To start with, always tray eggs from youngest to oldest. As the example shows us, there are two racks of eggs for every incubator (1 through 20). These will fill 10 incubators. The letters on the side indicate what set is going into the incubator. Notice that in Set A the racks are in perfect order whereas in Set B Rack 1 starts in Incubator 5. In Set C, Rack 17 starts in Incubator 5 and then back to Set A. This provides the best mix given the egg supply.
The aim of determining and managing incubation profiles is to achieve good hatch efficiency with the best quality at all times.
Cause and effect
A step programme in the hatcher means lowering the temperature to get the damper open. Timing is everything – the step process needs to be completed before the chicks overheat but if the steps down are premature then the chicks will run too cool. Monitoring chick temperatures will tell you exactly when to start. Remember that step programmes are designed to keep chicks from overheating not to cool them down.
How do we know our profiles are set up properly? We monitor hatch of fertile and chick quality per machine. This tells us how good a job we are doing with the fertile eggs we have. If we do not keep and use records then it will be impossible to fine tune operations and achieve optimum performance.
Remember there is a cause and effect for everything we do inside an incubator. Everything we do is to optimise broiler performance. The more we know about incubation and embryonic development, the easier it will be to determine and manage profiles. Our goal is to achieve good hatch efficiency with the best quality at all times.
[Source: World Poultry magazine Vol 30 nr 3, 2014]
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