Accelerating Embryonic Growth During Incubation Following Prolonged Egg Storage 1. Embryonic Livability - V. L. Christensen,2 J. L. Grimes, M. J. Wineland, and G. S. Davis Department of Poultry Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695-7608 2003 Poultry Science 82:1863–1868

The hypothesis was proposed that shorter incubation periods and faster growth rates for long-stored eggs would improve embryonic survival and poult hatchling quality. Increased incubation temperatures were tested for their efficacy in improving embryonic livability in fertilized eggs stored for 15 d prior to setting in the incubator compared to controls stored for only 3 d. Two temperature treatments were applied. In experiment 1, a 37.8C set point for dry bulb temperature was used to accelerate development for the initial 2 wk compared to the controls at 37.5C. Following treatment, the accelerated embryos were returned to the same machine as the controls. In experiment 2, higher temperature exposure was only for the initial week of incubation. The temperature and storage treatments were in a completely random 2 2 factorial arrangement of treatments. At the completion of 28 d of incubation, survival rates of all treatments were determined by opening all nonhatching eggs to differentiate truly fertilized eggs from unfertilized. Hatchability was determined by dividing the total number of poults on a hatching tray by the number of fertilized eggs on a tray. Incubator trays were the experimental unit. Tissues were sampled in both experiments to verify treatment effects on growth and metabolism. Hatching times were observed at 4-h intervals during the actual hatching process beginning at 25 d of incubation. It was concluded that delayed growth and depressed metabolism of fertilized turkey eggs stored for 15 d can be compensated for by exposure to higher incubation temperatures for the initial 1 or 2 wk of incubation.
http://www.poultryscience.org/ps/papers/03/p03C1863.pdf



Accelerating Embryonic Growth During Incubation Following Prolonged Egg Storage 2. Embryonic Growth and Metabolism - V. L. Christensen,2 J. L. Grimes, M. J. Wineland, and G. S. Davis Department of Poultry Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695-7608 2003 Poultry Science 82:1869–1878

The hypothesis was proposed that the improved embryonic livability observed when higher incubation temperatures were imposed on eggs stored for 15
d prior to setting might have basis in energy metabolism. To test the hypothesis, fertilized turkey eggs were incubated either for the first 2wk of development (experiment 1) or only the first week of development (experiment 2) at 37.8C compared with controls incubated at 37.5C. In both experiments, eggs were stored for either 15 or 3 d prior to setting. Viable embryos were selected randomly from each storage-by-incubation period treatment combination at 25 to 28 d of incubation and were sampled for blood, heart, and skeletal muscle tissues. Tissues were weighed and assayed subsequently for glucose or glycogen content. In experiment 2, the randomly selected embryos from each treatment combination were sampled at 7, 14, 21, and 28 d of incubation. Embryos at 7 and 14 d were assayed on a whole body basis, whereas at 21 and 28 d the bodies were dissected, and heart, liver, and skeletal muscle tissues were weighed and assayed for glycogen and lactate. Blood samples were collected between 25 and 28 d of incubation as in experiment 1 and assayed for glucose, creatine kinase, lactate dehydrogenase, and thyroid hormone concentrations. In both experiments, accelerated development was noted due to higher temperature and enhanced embryonic carbohydrate metabolism, and elevated thyroid hormone concentrations were observed compared with controls. It was concluded that a possible mechanism for the improved livability of faster growing embryos observed after prolonged egg storage might be due to better utilization of carbohydrate.
http://www.poultryscience.org/ps/papers/03/p03C1869.pdf



Pre incubation storage effects on hatchability and hatching time to lines selected for fast and slow hatching - Bohren, B.B., 1978. Poultry Sci. 67:581-583.


Relation of pre-incubation factors and post-hatching performance to length of incubation period. 1. Effect of egg weight and storage time on length of incubation period - MacLaury, D. W. and W. M. Insko Jr. 1968. Poultry Sci. 47:305-311.


Embryonic Malpositions in Broiler Chickens and Bobwhite Quail - H. R. Wilson,2 S. L. Neuman,3 A. R. Eldred, and F. B. Mather Department of Animal Sciences, University of Florida, P.O. Box 110910, Gainesville, Florida 32611-09102003 J. Appl. Poult. Res. 12:14–23

One of the factors contributing to failure of avian embryos to hatch is the positioning of the embryo at the end of incubation in such a manner that emergence from the egg is inhibited. Abnormal positions, or malpositions, may also be associated with other problems without directly affecting the ability of the chick to hatch. The effect of strain, breeder age, and gender of embryo on incidence of malpositions before hatching was determined in broiler embryos. The effect of strain, breeder age, pre-incubation egg storage, setting orientation, and turning during incubation on incidence of malpositions before hatching was determined in bobwhite quail embryos. Although there were variations among strains and between genders for incidence of malpositions, they were not statistically significant. Differences among settings and evaluators were as great as strain effects. No significant strain or breeder age effect on malposition incidence was found in quail. Long-term pre-incubation storage increased the incidence of quail embryos with head between the thighs, possibly related to delayed embryonic development. Setting quail eggs with the small end up resulted in 75% of the embryos with head in the small end of the egg. Eggs set normally but not turned had increased incidences of head in small end, beak away from air cell, and head over wing embryonic malpositions. Therefore, in these studies, the incidence of malpositions was affected by pre-incubation egg storage, egg orientation, and turning, whereas it was not affected by strain, embryo gender, and breeder age.
http://www.poultryscience.org/japr/papers/03/r0310014.pdf


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How are Embryo and Poult Viability, Hatchability, and Growth Affected by Storing Turkey Eggs for Long Periods? – Gaylene Fasenko, University of Alberta Poultry Research Centre News Vol. 6 No. 1, April 1997
Why Store Hatching Eggs? Cold storage of hatching eggs is a common management practice in the poultry industry. Hatching eggs are not incubated immediately after laying for a variety of reasons. The most obvious reason is that eggs are not incubated on the farms on which they are produced. Transport of eggs from breeder farms to commercial hatcheries means that eggs must be stored on-farm, as daily delivery of hatching eggs is not practical. Eggs may also be stored at the hatchery for several reasons. In times when hatching eggs are plentiful, incubator space may be limited therefore requiring storage of the surplus eggs. Storage of eggs may also occur if the hatchery has a reduction in the number of chicks or poults required for placement on grow-out farms. During the hot summer months in the southern United States hatching egg production declines. In this case, hatchery managers anticipate a reduction in egg production due to high temperatures, and accumulate eggs to maintain enough eggs for setting and subsequent poult placement on grow-out farms.
There are some negative effects of storing hatching eggs. Egg storage for more than 1 week is known to increase embryonic abnormalities and mortality. Eggs stored longer than 1 week also show reduced hatchability and an increase in the amount of incubation time required to hatch. Post-hatch growth and quality of chicks and poults from eggs stored for long periods also suffers.
http://www.agric.gov.ab.ca/livestock/aprc/news970601-2.html


Minimizing Embryonic Mortality -
The main purpose of the avian egg is to produce a viable, healthy chick. Embryogenesis is dependent on several factors that are referred to as the four basic principles of incubation. These include temperature, humidity, ventilation and mechanical agitation (egg turning). Light and sound have been implicated as environmental elements that affect embryo development, but do not have enough influence to be incorporated as major components of a commercial hatching program. Both of these factors influence time of hatching more than embryo survival. Modern incubators are designed with the four basic principles in mind to provide an optimum environment for embryo development and successful hatching. There are other factors that can affect embryo development and viability that can be managed successfully.
http://department.caes.uga.edu/poultry/tips/2002%20Sept.%20HB%20tip%20B%20F_LH.web.pdf


Developmental Stability of Broiler Embryos in Relation to Length of Egg Storage Prior to Incubation - Servet Yalin and Paul B. Siegel, 1 Ege University, Faculty of Agriculture, Department of Animal Science, Izmir-Turkey 2Virginia Polytechnic Institute & State University, Department of Animal and Poultry Sciences, Blacksburg, Virginia USA
The effects of storage of eggs for 0, 2, 8, 14, or 18 days prior to incubation, as measured by growth and developmental homeostasis of bilateral traits, were studied in broiler embryos. Data were obtained on hatchability, and for 10 embryos from eggs selected at random at 10, 14, and 18 days of incubation and at hatch from each storage period. Skeletal traits included lengths of left and right face, wing, tibia, femur, and shank as well as weights of the heart and left and right lungs. Eggs stored for 14 and 18 days had poorer hatchability than those stored for 0 and 2 days, with the 8-day storage group intermediate. There was a trend (P=0.08) for reduced lung weights of embryos from eggs stored for 18 days before incubation, whereas length of storage had no effect on heart weights. Femur and tibia lengths were affected by length of preincubation storage. Lengths of femur, tibia and shank differed among embryonic ages demonstrating that these bones grow at different rates during incubation. Polynomial equations are provided for size of traits. Developmental asymmetry of bilateral traits was influenced by length of preincubation storage and embryonic age. Relative asymmetry declined steadily from 10 days of incubation towards time of hatch.
http://wwwsoc.nii.ac.jp/jpsa/jabst-e/2003/03%20eabst/03-298.html


Egg Storage and Effects on Hatchability - Dr. Gaylene Fasenko, University of Alberta
Hatching eggs, whether produced by chickens or turkeys, are not usually incubated immediately after lay. Hatching eggs are stored at both hatcheries and breeder farms, as the latter are usually located a considerable distance from one another and from the hatchery, thus daily egg pickup from all farms would be inefficient. When hatching eggs are plentiful, eggs are stored at the hatchery until sufficient incubator space is available. When the number of eggs is limited, they may be stored at the hatchery until there are enough to fill large incubator racks. In preparation for a drop in egg production during hot weather, the hatchery may stockpile eggs in storage to maintain chick and poult production levels during the summer months.
Hatching eggs are usually stored at temperatures between 12 and 18°C which cools the eggs and limits development of the embryo. A relative humidity between 70 and 80% is maintained to prevent loss of moisture from the eggs.
Hatchery managers strive to incubate eggs after three to four days of storage time (on-farm and hatchery storage combined). This is because egg storage for more than seven days increases embryo death. Previous experiments have shown that chick and poult quality also suffers when eggs are stored longer than seven days.
A number of methods have been investigated to improve the hatchability of eggs store for more than seven days. These methods include varying storage temperature and humidity levels; enclosing eggs in plastic airtight bags; enclosing eggs in plastic bags and injecting either oxygen, carbon dioxide or nitrogen into the bags; and sorting eggs small end up, or turning eggs during storage (see Mayes and Takeballi, 1984 and Meijerhof, 1992). One of the most successful methods for improving hatchability has been to warm eggs prior to storage.
It is well known that the amount of incubation time required for an egg to hatch is lengthened when hatching eggs are stored for extended periods prior to setting. There are two possible reasons for the increased incubation period. It may be that the embryo from a long-term stored egg does not begin development after normal incubation temperatures are provided. The second possibility is that the development of embryos from stored eggs proceeds at a slower rate thorough the first period of incubation.
Experiments were conducted at the University of Alberta Poultry Research Centre to investigate the effects of long-term storage on embryo growth and hatchability, and to determine if incubation prior to storage would improve the hatchability of long-term stored eggs from modern broiler breeder strains.
http://www.poultryindustrycouncil.ca/Factsheets/Factsheets/fact122.htm