Travis Schaal
2007 HHMI Presentation
Mentor Dr. Gita Cherian
Department of Animal Sciences

Background 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 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
Images courtesy of www.embrex.com
o Automated systems have already been integrated into hatcheries

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 nonhatched 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
Hatchability
100
90
80
70
60
50
40
30
20
10
0
Non-Inj Control Veg
Treatment
10 IU 20 IU

Results
60,00
50,00
40,00
30,00
20,00
10,00
0,00
Non-inj
Chick weight
Control Veg
Treatment
10 IU 20 IU

Results
40
30
20
10
0
60
50 b
Control Veg nmol Vit E / ml Plasma a, b a
Non-Inj
Treatment
10 IU a, b denotes statistical difference a
20 IU

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