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

Modulating Lipid Metabolism to Enhance Hatchability of

Chicken Eggs

Travis Schaal2007 HHMI Presentation

Mentor Dr. Gita Cherian Department of Animal Sciences

o Poultry products are an important protein source for the world’s population

o 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)

o Hatchability problems resulted in a 500 million dollar loss to the poultry industry in 2005

Background

Background

o About avian incubation:

o 21-day incubation period for a chicken egg

o 5.5-6g of yolk fat is the only source of fatty acids available to the growing embryo

o 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

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

Background

o What is in-ovo technology?o Commonly used for vaccination

programs

o Insertion of needle into the egg to administer vaccine to embryo, air sac or amnion

o Automated systems have already been integrated into hatcheriesImages courtesy of www.embrex.com

Background

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

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

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

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

Results

Results

Results

Results

a, b denotes statistical difference

Results

o Results Pending:

o Tissue Vitamin E concentrations

o Tissue and plasma fatty acid status

Image courtesy: http://www.fisherfeeds.com/graphics/broiler.jpg

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