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Probiotics/Prebiotics (general info)
« Thread started on: Sep 15th, 2006, 03:50am »
Probiotics are live, nonpathogenic bacteria that contribute to the health and balance of the intestinal tract. They are given orally to poultry to help the birds fight illness and disease. Prebiotics are nondigestible foods or nutrients that probiotics need to stimulate metabolism. They feed the beneficial bacteria and modify the composition of intestinal microflora so probiotics can predominate.
The conditions of poultry production have changed over the years. Breeding and husbandry have changed in respect to faster growing and more productive birds, hatching in more or less sterile environment, more birds per square meter, use of antimicrobials as a result of intensive production etc. These changes lead to stress conditions in the birds as well as in a delayed formation of the gastro-intestinal microflora which may result in less natural resistance of the birds against contamination or infection with pathogens, as well as in a delayed formation of the gastro-intestinal microflora because of the lack of contact with natural and environmental micro-organisms.
Healthy birds with a stable gastro-intestinal microflora are thought to be maintained by using antibiotics in preventive dosages but these low dosages have negative effects on lactobacilli and other lactic acid producing bacteria. Lactobacilli constitute the largest part of aerobic microflora in the gastro intestinal tract and are very susceptible to antibiotics. To decrease the use of antibiotics, whose usage may result in bacterial resistance and in the formation of residues in organs and tissues of treated birds, the use of probiotic can considered. There are some differences in the time span in which action occurs, antibiotics become active at once while the effects of probiotics last for days or weeks.
Defined as cultures of living micro organisms which are able to proliferate in the host intestinal tract resulting in a balanced microflora. They are mainly composed of Lactobacilli, Streptococci, Bifido bacteria, Bacilli and Yeasts. These micro organisms inhibit growth of potentially pathogenic micro organisms by lowering the pH through production of lactate, lactic acid and volatile fatty acids.
Application of Prebiotics and Probiotics in Poultry Production
"ABSTRACT The intestinal microbiota, epithelium, and
immune system provide resistance to enteric pathogens.
Recent data suggest that resistance is not solely due to
the sum of the components, but that cross-talk between
these components is also involved in modulating this
resistance. Inhibition of pathogens by the intestinal microbiota has been called bacterial antagonism, bacterial interference, barrier effect, colonization resistance, and competitive exclusion. Mechanisms by which the indigenous intestinal bacteria inhibit pathogens include competition for colonization sites, competition for nutrients, production of toxic compounds, or stimulation of the immune system. These mechanisms are not mutually exclusive, and inhibition may comprise one, several, or all of these mechanisms. Consumption of fermented foods
has been associated with improved health, and lactic acid bacteria (lactobacilli and bifidobacteria) have been implicated as the causative agents for this improved health. Research over the last century has shown that lactic acid bacteria and certain other microorganisms can increase resistance to disease and that lactic acid bacteria can be enriched in the intestinal tract by feeding specific carbohydrates. Increased bacterial resistance to antibiotics in humans has caused an increase in public and governmental interest in eliminating sub-therapeutic use of antibiotics in livestock. An alternative approach to sub-therapeutic
antibiotics in livestock is the use of probiotic microorganisms, prebiotic substrates that enrich certain bacterial populations, or synbiotic combinations of prebiotics and probiotics. Research is focused on identifying beneficial bacterial strains and substrates along with the conditions under which they are effective.
(see link voor de FULL TEXT ARTICLE) "