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

oPoultry products are an important protein source for the worlds population oOut of the 11 billion eggs set in US commercial hatcheries in 2005, 2 billion did not hatch (Schaal and Cherian Poult Sci 86(3): ) oHatchability problems resulted in a 500 million dollar loss to the poultry industry in 2005 Background

oAbout avian incubation: o21-day incubation period for a chicken egg o5.5-6g of yolk fat is the only source of fatty acids available to the growing embryo oIntense 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:

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:

Background oWhat is in-ovo technology? oCommonly used for vaccination programs oInsertion of needle into the egg to administer vaccine to embryo, air sac or amnion oAutomated systems have already been integrated into hatcheries Images courtesy of

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

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 courtesy:

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

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)

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

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

Results

a, b denotes statistical difference

Results o Results Pending: oTissue Vitamin E concentrations oTissue and plasma fatty acid status Image courtesy:

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

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