1 Wayne Farms LLC, Albertville, Alabama 35950 2 Department of Biological Sciences, Alabama State University, Montgomery AL 36104 3 Alabama State Veterinary Diagnostic Laboratory, Auburn AL, 36849 4 Department of Poultry Science, College of Agriculture, Auburn University, Auburn, AL 36849 Effect of Incubational Egg Turning Rate on Gut Development in the Chick: Gut Morphology and Developmental Biomarkers. Victoria N. Holland 1 *; Yewande O. Fasina 2 ; Jonathan Roberts 3 ; Wallace Berry 4
Transcript
1Wayne Farms LLC, Albertville, Alabama 359502Department of Biological Sciences, Alabama State University, Montgomery AL 361043Alabama State Veterinary Diagnostic Laboratory, Auburn AL, 368494Department of Poultry Science, College of Agriculture, Auburn University, Auburn, AL 36849
Effect of Incubational Egg Turning Rate on Gut Development in the Chick: Gut Morphology and Developmental Biomarkers.Victoria N. Holland1*; Yewande O. Fasina2; Jonathan Roberts 3; Wallace Berry4
Introduction•A chick’s gut is not mature at hatching.•Further maturation over several days has to take place for the gut to become functional (Uni, et al, 1996). •Transport proteins and digestive enzymes appear as the gut matures.
• Increased gut maturation is associated with increased livability and growth.
Uni, Z., Y. Noy, and D. Sklan. 1996. Developmental parameters of the small intestines in heavy and light strain chicks pre and post-hatch. Br. Poult. Sci. 36:63–71.
Introduction•Embryonic development is controlled by incubation conditions.
•Egg turning is one condition critical to development of the chick embryo (Randle and Romanoff, 1949).
•Egg turning rate influences incubation length, hatchability, chick quality, and chick growth potential (Tona et al., 2005).
Randle, C. A., and A. L. Romanoff. 1949. Maldevelopment of the avian amnion as influenced by some environmental conditions. Poult. Sci. 28:780-781.
Tona, K., O. Onagbesan, V. Bruggeman, K. Mertens, and E. Decuypere. 2005. Effects of turning during incubation on embryo growth, utilization of albumen, and stress regulation. Poult.
Sci. 84:315-320.
Introduction•The range of egg turning rates for optimum hatchability for poultry eggs is well understood.
•Effects of egg turning rates on individual organ systems are not well studied.
Altering egg turning rate will promote or suppress gut development.
Objective•Examine gut development (morphology, gut specific proteins) in embryos exposed to a modified turning rate during incubation. Optimize incubation conditions to improve
livability and early growth of broiler chickens.
Ten commercial strain broiler hatching eggs per treatment were incubated at 37.5 C, and 60% relative humidity. Eggs turned through 90 degrees.
Turning TreatmentsControl-Eggs turned 12/day
2x- Eggs turned 24/day
Materials And Methods
Material And Methods
•Embryos were taken at 18 days of incubation.•Length of Ileum taken from end of duodenal loop to cecal junction. •Weights were taken for the egg, embryo, and gut samples.•Ileal samples fixed in 10% formalin.
Material And Methods
•Tissues were paraffin embedded, sectioned, deparaffinized, mounted on slides.•Representatives stained with a standard hematoxylin and eosin stain.•Digital micrographs were made of each ileum tissue section.
Material And Methods
•Villus length and number measurements were made using image analysis software (Image-J).
•Villus count and villus length were measured as the average of counts/measurements from three fields of 300 x 300 pixels for each sample.
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Material And Methods
Immuno-peroxidase method used to identify the presence of two proteins regarded as markers of functional gut development.
Material And Methods Statistical Methods: •Only two incubators were available. •Adequate replication for a valid statistical analysis was not possible. •(As an academic exercise) The data collected were analyzed as if individual embryos were replicates. •Unpaired T test (Graphpad Prism 6)
Relative Embryo Weight (g/g egg weight), n=8.
Change to Ileum
Representative H&E stain gut section.
Representative Pept -T1 stain section.
Representative SI section stain.
Summary: Gut
Parameter Control 2XEmbryo Weight
Ileal Weight Ileal Length
Villus Number Villus Length
Summary: Gut Marker Proteins
Gut Marker Protein Control 2XPept-T1 ✔ ✔
SI ✔ ✔
Discussion:
•The greater turning rate of the 2X Treatment appeared to stimulate ileal mass independently of an increase in embryo weight.
•The apparent increase in ileal mass was not due to an increase in ileal length.
Discussion:
•The number of villi per cross section was not increased by the 2X Treatment. Taken with a shorter ileum, this would support the conclusion that increased turning rate reduced the overall number of villi in the intestine.
Discussion: •Villus length appeared to be longer with the 2X Treatment. Longer villi may explain the greater mass of the ileum even though ileal length was less.
•Longer but fewer villi may alter absorptive area.•Longer, but fewer villi may have implications for gut mucosal cell proliferation.
Discussion:
•The presence of Pept-T1 and SI in all sections suggests that these are not sensitive markers for gut development at the stages examine.
•Quantitative observations of these, or other markers may be more informative.
Conclusion:
Results support the hypothesis that altering egg turning rate will alter embryonic gut development.
Further Work •Repeat the current study with larger egg numbers and replicate groups.•Explore lower turning rates as well as higher•Extend observations to 1 week old hatched chicks.•Diversify and markers of intestinal development.
