The second phase of the scientific feeding of poultry required definition of
biochemical mechanisms underlying metabolism. Understanding how individual
nutrients were absorbed and then incorporated into poultry meat and eggs
accelerated advances in feed formulation.
In addition it became
possible to combine related disciplines such as immunology, stress physiology
and environmental management into nutritional programs which optimized
production.
The most recent development encompasses the emerging
science of nutrigenomics. This discipline deals with the mechanisms by which
nutrients modify gene expression at the cellular level.
Applying data
generated by DNA micro-arrays ("gene chips") it is now possible to identify
specific genes that are activated ("up-regulated"), deactivated
("down-regulated") as a result of feeding specific
nutrients.
Analysis of gene responses using sophisticated software
and equipment, which is now possible through advances in nanotechnology, will
link genetics with nutrition and enable producers to achieve the inherent
potential of breeding stock and to attain higher levels of efficiency and
return.
The potential for nutrigenomics was recently demonstrated in
an international symposium organized by a US feed additive manufacturer which
was attended by 1,500 scientists and affiliates of intensive livestock
industries.
Presentations by scientists confirmed advances in
refining technology to identify the genetic basis for selection of ingredients
which will be applied to formulating diets.
Comparing the action of
selenium provided as either inorganic sodium selenate or organic
selenomethionine was offered as an example of this new approach to specifying
nutrient requirements.
Supplying selenium in the organic form
resulted in marked up-regulation of genes coding for the synthesis of enzymes
associated with inherent antioxidant mechanisms. In contrast dietary
supplementation with sodium selenate did not stimulate gene
activity.
Development of nutrigenomics will require expansion of the
micro-array gene expression database (MGED) which was founded in 1999 to develop
standard techniques and to provide oligonucleotide
combinations.
Complementary development of software to interpret
strands of micro-arrays will also be required to achieve more widespread use of
the technology.
Nutrigenomics offers the potential to integrate
aspects of nutrition, genetic selection, protection against disease and response
to environmental stress.
Hopefully funding will be available to accelerate research.
A climate of cooperation will encourage interchange of ideas among academia and
industry, which will benefit both producers and consumers of poultry and other
livestock products.
By: Simon
Shane