Feed Strategy - April 2018 - 20
20 ❙ FeedStrategy
IMPROVING IMMUNE RESPONSE
(biﬁdobacterium, lactococcus, streptococcus, lactobacillus,
bacillus subtilis, etc,.); or complex flora.
Microbiota aids immunity
Fighting excessive inﬂammation
Microbiota is very influential in animal immunity
either directly by avoiding pathogen installation in the
digestive tract or indirectly. Digestive tract colonization
differs depending on species.
"In horses and rabbits, coprophagia behavior is a natural way for the youngsters to benefit from their mother's
microbiota," said Sylvie Combes, of the French National
Institute for Agricultural Research (Inra).
Nathalie Le Floc'h, an Inra researcher dedicated to
pigs, shows that feeding strategy is also very important
to fight inflammation. Any biological function dedicated
to health uses specific nutrients: digestive mucosa itself
(physical and biological barrier against pathogens) and
proteins, like mucine, immunoglobulins and liver proteins.
"Some immune [systems] answer, like inflammation, induces radical change in metabolism and some nutrients play
direct or indirect action on inflammation," Le Floc'h said.
Inflammation is one of the innate immune responses
against toxins and pathogens. Many chemical reactions
occur during inflammation, which is needed to trigger
adaptive immune response. But inflammation might be
excessive. If it becomes systemic, excessive production of
cytokines pro-inflammatory (IL1, IL6, TNFa) can play
several roles: they induce fever, increase protein catabolism and decrease protein synthesis in muscle, increase
liver synthesis of inflammatory proteins and gluconeogenesis. This systemic inflammation will amplify local
inflammation and tax the organism.
"We must keep in mind that this inflammatory response occurs during a lot of diseases - not only infectious disease, but also stress like weaning or group changes or even poor farming conditions," Le Floc'h said.
Inflammation costs are quite high for a sick animals'
metabolism: mycotoxins might reduce feed consumption by
23 percent, digestive disease by 10 percent, and even poor
housing affects feed consumption by at least 4 or 5 percent.
How nutrition influences
dairy cow health,
To increase digestion efficiency, researchers used tools
to control microbiota: soluble or insoluble fibers, oligosaccharides from yeast or plants, and lactobacillus. Even if
microbiota is quite stable, a feeding strategy might help to
modulate it in the first part of animal life. Then, ecological
succession of species will drive microbiota to its "maturity."
For example, rabbits' gut flora is "mature" around 42
days of life. The gut flora is, then, stabilized and will show
a high resiliency after that. Researchers are working on
four stages: modification of first bacterial species, optimization of installation, acceleration of maturation or modulation of flora with new species (i.e., probiotics).
Research has shown several ways for nutrition to modulate immunity linked to microbiota: quantity and quality
of fibers, e.g., lignocellulose, hemicellulose and their ratio;
starch and proteins; prebiotics (competition by masking the
binding sites of pathogenic bacteria to the mucosa); probiotic
skeeze | pixabay.com
that beta-glucan increased phagocytosis and provided better protection from infection.
Inﬂammation's impact on metabolism
The impact of inflammation is even more important on
daily weight gain, which shows that inflammation not only
induces ingestion decreases, but also other mechanisms.
For example, glucose metabolism is highly modified as
inflammation demands high doses of glucose, but animal
muscles are no more able to use insulin, the hormone needed
to clear glucose from plasma. Glucose metabolism is then
www.WATTAgNet.com ❙ April 2018