Download Modulating Lipid Metabolism to Enhance Hatchability of Chicken Eggs

Modulating Lipid Metabolism
to Enhance Hatchability of
Chicken Eggs
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
Percent hatchability
80
70
60
50
40
30
20
10
0
Non-Inj
Control Veg
10 IU
Treatment
20 IU
Results
Chick weight
60.00
Weight grams
50.00
40.00
30.00
20.00
10.00
0.00
Non-inj
Control Veg
Treatment
10 IU
20 IU
Results
nmol Vit E / ml Plasma
nmol vit E per ml plasma
60
50
a
a
10 IU
20 IU
a, b
40
b
30
20
10
0
Control Veg
Non-Inj
Treatment
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