Effect of Angle of Turning and Shaking Agitation During Incubation on Embryo Development and Hatchability

Abstract

CUTCHIN EVANS, HEATHER RENEE. Effect of Angle of Turning and Shaking Agitation During Incubation on Embryo Development and Hatchability. (Under the direction of Michael J. Wineland.)

Successful incubation is the result of many factors, including turning the eggs to a 45° angle once an hour through day 18 or 19 of incubation. Not turning eggs at all during incubation leads to high percentages of embryonic mortality throughout incubation as well as several distinct extra-embryonic abnormalities, such as a decrease in sub-embryonic fluid formation, an increase in the amount of residual albumen after d18, and others which can be harmful to chick weight at hatch. However, turning eggs creates hot spots in the machine, therefore developing a way to increase air flow by turning egg less or not turning at all but still providing change in orientation of the egg would increase the hatchability as well as provide a more even chick quality across the machine. Three trials were performed to examine the effects of turning at reduced angles of 15°, 30°, 35° and 40° once an hour as well as increased frequency of turning at a reduced angle of 15° three times an hour. Eggs were obtained from prime age broiler breeder flocks and stored for 1-3 days prior to incubation to imitate industry ideal conditions. Subembryonic fluid was sampled at d6 of incubation and embryos were sampled at d18. At hatch, embryonic day of death was noted as well as any abnormalities such as residual albumen, malpositions or excessive urates. Overall it was determined that turning at 15° was not suitable for hatchability and results were noted similar to those reported by other authors that did not turn eggs during incubation. Turning 30° is not as harmful as turning 15°, but not as adequate as turning 45°. Increasing the frequency of turning 15° to three times an hour alleviated some of the detrimental effects of turning 15° once an hour, but was still not as successful as 45°. Turning 35° and 40° did not affect hatchability and embryonic mortality significantly. Shaking, or agitation, of the egg was attempted in a series of trials where the speed, frequency, and duration of shaking were manipulated to determine a combination that would be suitable for incubation in the industry. Eggs from prime age broiler breeder flocks were used for the four trials. Two similar machines were utilized; one that turns eggs conventionally (turns) and a modified incubator that moves eggs through a 4.5cm distance (shakes). Eggs were shaken intermittently either the entire incubation period or during parts and then turned. A control group of turned eggs were included in each trial for comparison. Overall, it was determined that shaking agitation did not produce suitable for hatch of fertile for industry use. Turning eggs at least d1-3 of incubation provides a better hatch of fertile than shaking eggs throughout incubation. Shaking eggs leads to higher percentages of early and late mortality, residual albumen and malpositions. Interestingly, the chicks that do hatch from shaken eggs are similar in quality to those from turned eggs, as indicated by their yolk free body mass. In conclusion, reduced turning angles of 35° and 40° do not seem harmful to embryonic development, though 30°, 15° once an hour and 15° three times an hour do. Shaking agitation has been determined to not be advantageous for hatch of fertile, however further research is warranted on combinations of speed, frequency, and duration of shaking that may prove more favorable.