The benefits of extra centimetres
Published: March 9, 2009
By: Ron Meijerhof - HatchTech Incubation Technology (The Netherlands)
During incubation, the content of an egg is transformed into a living, day old chick. This miracle of life is the result of a very delicate process, that requires a high level of understanding and control for optimum results. Everybody in the (incubation) industry knows how sensitive these processes are and how subtle the changes in settings and conditions are that make the difference between good and poor results.
But the question arises, what are good results in an incubation process, which results from incubation are important for the poultry production chain. And if we have determined that, how can we measure and quantify them, preferably in an objective and repeatable way.
Traditionally, the performance of a hatchery is judged on the quantity of chicks produced from the (fertile) eggs set. More often even, the judgement is based on the cost price per chick hatched. Although these are important issues, they do not really pay justice to the role a hatchery plays in a total integration. And although survival rate in the first week is an important trade and is related to quality of the incubation process, also this measurement is not adequate to express the importance of incubation as a part of the whole production chain.
Research has shown that the quality of the day-old chicken, and with that the quality of the incubation process, has a big influence on performance of the broilers at processing age. In an experiment at Penn State university (Gladys et al, 2000) a difference of 5 to 7 points in feed conversion for broilers at 6 weeks of age was observed, depending on the temperature conditions in the last 5 days of incubation. As this is 100 to 140 grams of feed for a 2 kg broiler, it is obvious that the benefit of a good incubation process goes far beyond a good hatch of fertiles or low costs per chick hatched.
The most important driving force during incubation is temperature, and then especially the temperature that the embryo experiences inside the shell: the embryo temperature. Fluctuations away from the optimum embryo temperature result in a less optimum development of the chick, and consequently a performance below maximum. (Lourens et al, 2004). Several researchers focus at this moment on the effects of this temperature on the incubation process, chick quality and its effect on broiler performance. In this article I want to focus on the effects we can observe on the day old chick.
During incubation, the content of the egg is used by the embryo to build up its body. The energy that is needed for that process comes for a large extent out of the burning of the yolk. As we know, the remaining of the yolk is taken up in the body cavity before hatching and is used by the chick in the first days after hatching. This means that if we measure day old chick weight, we measure the amount of chick that is formed during incubation together with the remaining yolk. This weight does not tell us how much chick is formed during incubation. For instance, a 45 gram day old chick can be a combination of 35 gram real chick plus 10 grams of residual yolk, but also of 42 gram real chick plus 3 grams of residual yolk. Although this is in absolute numbers only 7 grams difference in body tissue, it does mean that the 42 gram chick has 20% more body tissue developed then the 35 gram chick. This shows in the weight of the so called yolk free body mass (chick without yolk) but also in the length of the chick if we measure for instance the length of the spine or the length of the total chick from tip of beak to tip of toe, when stretched out over a ruler. Research (Wolanksi et al, 2004) has shown a good correlation between length of the chick and amount of yolk free body mass.
We can imagine that a chick that builds up more body tissue during incubation and became larger at the moment of hatching, might be considered a more developed chick. At the end of the incubation process the total length of the embryo (tip of beak to tip of toe) increases with about 1 cm per 24 hours, which suggests that a longer, more developed embryo at moment of hatching is in a way more "mature". Our first measurements indicate that this extra development does not only show in length of the chick, but for instance also in length of its intestinal tract.
Although we are getting more knowledge about the influence the length and development of the day old chick has on bird performance, a lot of the consequences are at this moment still to be investigated. To mention a view of them:
- Research has shown that there is a positive correlation between length at moment of hatch and broiler performance at 6 weeks of age.
- We also have observed that the length of the intestinal track increases with chick length, which perhaps is also an indicator for a more developed gut system.
- The yolk contains the maternal anti bodies that mother hen passes on to her offspring to protect them against the disease challenges she is experiencing. If there is a difference in utilisation of the yolk during incubation, it can be questioned if the immune system in the day old chick develops in the way we expect.
- When we vaccinate chicks in-ovo, we want to deliver the vaccine in the amnion fluid, swallowed by the embryo during incubation. When the development at a certain moment during incubation is not sufficient and the embryo is too small, the vaccine will not be delivered in the amnion but in the allantoic membrane, which makes the vaccination ineffective.
Although there is still a lot unknown about the effect and value of chick length, we do know that an increase in length has a positive effect on broiler performance, and that an extra centimetre in development pays off.
Literature cited:
Gladys, G.E., D. Hill, R. Meijerhof, T.M. Saleh and R.M. Hulet, 2000. Effect of embryo temperature and age of breeder flock on broiler post hatch performance. International Poultry Scientific Forum Abstract 179
Lourens, A., H. van den Brand, R. Meijerhof and B. Kemp. 2005. Effect of eggshell temperature during incubation on embryo development, hatchability and post-hatch development. Poult. Sci. 84: 914-920.
Wolanski, N.J., E.Luiten, R. Meijerhof and A.L.J. Vereijken, 2004. Yolk utilisation and chick length as parameters for embryo development. Avian Poult Biol rev. 233-234
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19 de septiembre de 2012
A very informative article which brings to light the importance of the processing of the hatching eggs from the time these are laid to the timing of setting. Additional research would be needed to find the correlation between the age of the eggs at the time of setting with the maturity of the embryo, hence the chick length and yolk free body mass, at the time of hatching.
Soavet
21 de marzo de 2009
Surely in ovo vaccination is a recent technology of ealy chick embro vaccination, not yet practiced in Nigeria and many developing countries but frankly speaking it will soon become very relevant in the management of many post hatchery vaccination failures.
A particular poultry disease of concern is Marek's that are vaccinated for at hatcheries, but to which embarassing outcomes of post hatchery vaccination is now a common features on the field.
The pending challenge now is if an in ovo vaccination will confirm a solid immunity beyound 12 weeks of age?
Can we be able to identify by empirical information post hatchery Marek's failure that can be traced to the hatchery as distinct from a direct field outbreak?
If post hatchery immunity to Marek's fails at 12wks, is it possible to identify a best period to trigger an amnestic response to a hatchery vaccination with HVT vaccines?
I have a 25-year cumulative data on post hatchery vaccination failures in Nigeria with very poor evidences of solid immunity.
My study is still on going and I am interested in the role in ovo hatchery vaccination will play in solving this problem.
I wish to draw attention of interested groups that may want to collaborate with me for this study to be free to contact me through Engormix.com.
Thanks.
Dr Stephen Adejoro
19 de marzo de 2009
Believe me this is a sincere and concerted effort made by a professional. The enlightenment made on the subject-matter are worthy of consideration for optimal diversion into hatchery performance for more quality chicks production.
...that an extra centimetre in development pays off. Now, if this assertion is anything to go by, then, the stakeholders (including the author) should go extra miles to research deeply into improving on the usage of in-ovo vaccines to address/correct the specific situation in the embryo such that would ensure better performance of the broiler chicks once- and- for- all.
Thank you.
19 de marzo de 2009
Bonjour. Je vous felicite pour votre travail et jespere avoir la chance de pratiquer cette methode. Bon courage.
18 de marzo de 2009
This is a very beautiful article. It is full of intellectual material. However, the issue of in-ovo vaccination is a new innovation to me. I have never heard of it. It is not used in Africa. Anyway. If I know about the process, I may likely be the first to use it. My hatching factory will start operations in Nigeria, Moniya, Ibadan. We want people like Dr. Adejaro to be in contact with us. Dr. Adejaro is a member of this forum. He contributed with an article on this forum as well.
Trouw Nutrition
17 de marzo de 2009
The factor that seems to influence yolk utilization most is temperature. If the temperature is off, the development of the embryo is not optimal, and consequently the transition from yolk to embryo is not optimal, and more yolk is left over.
The question about maximum utilization of the yolk is actually a question if the birds needs a minimum amount of yolk as residual yolk for the first days after hatch.
I dont think we know that answer. A lot of people are of opinion that a bird needs a certain minimum amount, but the fact that all the chicks that die before 3-4 days of age in the field still contain residual yolk suggests in my opinion that there are not a lot of birds that die from lack of yolk. It seems to me that they die more often from not being able to take up the yolk, and not because there is not enough yolk left over for uptake.
If that is the case, then in my opinion we better get maximum transfer of yolk into embryo during incubation, which means the less yolk is left over at hatch the better off we are.
Trouw Nutrition
17 de marzo de 2009
The best day of in-ovo injection actually depends on the development of the embryo.
If the embryo is too small, you inject into the allantois, which means the vaccin is not effective.
If the embryo is too big, you have a risk of injecting it in the breast, neck or head. That gives good vaccination, but of course bears a bigger risk for the embryo.
As the temperature profile determines the speed of development, we can imagine that not all machines have the same optimum moment of vaccination. We know that for optimal results, some types of machines require a bit later injection than others, because their initial temperatures of the embryos are lower.
But in general we are better off injecting too late than injecting too early, as the risk of injecting in the allantoic and then have birds that are not vaccinated at all is bigger than injecting to late and loose some chicks because of injecting them in the head or neck.
In ovo nutrition is indeed a new development with a lot of opportunities. By injecting the eggs with nutrients, we can overcome a specific shortage that has developed during incubation, and in that way safe chicks that otherwise would not have the energy to hatch.
Atthis moment I dont know if in ovo feeding can lead to more development. As the time from injecting to hatch is relatively short, we should not expect too much difference, but if we can compensate for a specific nutrient that is missing for development, we might see an effect.
Exotic Biosolutions
12 de marzo de 2009
Dear Mr. Ron,
Good informative article. What are the factors responsible for maximum utilisation of yolk? What is the maximum percentage of utilisation of yolk during the incubation stage?
9 de marzo de 2009
Hi Ron,
Very Informative article.
Which is the best day for in ovo vaccination?
People talk about in ovo nutrition?
Can the extra length be improved through in ovo nutrition?
Romila
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