Modulating Lipid Metabolism to Enhance Hatchability of Chicken Eggs

1. Modulating Lipid Metabolism to Enhance Hatchability of Chicken Eggs Travis Schaal 2007 HHMI Presentation Mentor Dr. Gita Cherian Department of Animal Sciences

2. Background • Poultry products are an important protein source for the world’s population • Out of the 11 billion eggs set in US commercial hatcheries in 2005, 2 billion did not hatch (Schaal and Cherian Poult Sci 86(3): 598-600 2007) • Hatchability problems resulted in a 500 million dollar loss to the poultry industry in 2005

3. Background • About avian incubation: • 21-day incubation period for a chicken egg • 5.5-6g of yolk fat is the only source of fatty acids available to the growing embryo • Intense increase in the uptake of poly unsaturated fatty acids (PUFA) by the developing embryo beginning at day 14 of incubation (Cherian et al., 1997) Image courtesy: www.natureform.com/kb/index.php?article=1004

4. Background • Uptake of fatty acids causes increased oxidative stress for the embryo • Antioxidant protection may be helpful for the developing embryo through the hatching process Image courtesy: http://www.ext.vt.edu/resources/4h/virtualfarm/poultry/poultry_incubation.html

5. Background • What is in-ovo technology? • Commonly used for vaccination programs • Insertion of needle into the egg to administer vaccine to embryo, air sac or amnion • Automated systems have already been integrated into hatcheries Images courtesy of www.embrex.com

6. Background

7. Background • Nutrient supplements for in-ovo research: • Substances that modulate metabolism: • Carbohydrates • Enzymes to stimulate absorption • Other Nutrients: • Amino Acids ? • Carnitine ? • Fatty Acids ? • Antioxidants ? Images courtesy of www.embrex.com

8. Hypothesis It is hypothesized that the embryos receiving an exogenous supply of vitamin E will have increased vitamin E deposition in tissues and enhanced hatchability with decreased oxidative stress http://animalscience.ucdavis.edu/AvianResources/Photo%20Gallery.htm Image courtesy: http://www.elcivics.com/chicken_hatched_holiday.jpg

9. Objective To determine the effect of exogenous supply of vitamin E on chick plasma and tissue vitamin E and PUFA concentrations as well as hatchability Image courtesy http://animalscience.ucdavis.edu/AvianResources/Photo%20Gallery.htm

10. Methods • Commercial broiler eggs acquired from local hatchery • Total of 100 eggs placed in treatments of 25 eggs: • Two treatments injected in-ovo with vitamin E at day 14 of incubation (10 IU and 20 IU) • Two treatments kept as controls (positive – veg oil and negative – no injection)

11. Methods • Incubation conditions standard for commercial operations • Hatched chicks counted and non-hatched eggs broken open to determine embryo status • Sacrifice hatched chicks (n=6) for tissue and blood samples from each treatment

12. Methods • Samples collected: • Blood (plasma) • Marker • Brain • Tissue with high polyunsaturates • Heart • Fatty Acid oxidation • Liver • Lipogenesis • Yolk Sac • Reservior • Data analyzed by SAS one way analysis of variance and means by Duncan multiple comparison with level of significance p <0.05

15. Results

16. Results

17. Results

18. Results

19. Results a, b denotes statistical difference

20. Results • Results Pending: • Tissue Vitamin E concentrations • Tissue and plasma fatty acid status Image courtesy: http://www.fisherfeeds.com/graphics/broiler.jpg

21. So What? • Exogenous supply of vitamin E enhanced plasma vitamin E concentrations: • Plasma is only a marker, tissue vitamin E will provide more information • Antioxidants may provide added protection in embryogenesis and throughout hatching • Future work to include increased number of eggs and grow-out of chicks

22. Acknowledgements • Howard Hughes Medical Institute • Dr. Gita Cherian • Dr. Kevin Ahern • D.G., Doug, Mare, and Jaime