Feed Management - July/August 2010

consideration or in a liquid suspension added to drinking water. As with all supplements cost effectiveness is critical to commercial acceptability. The benefits from a probiotic may be influenced by intercurrent nutritional and managemental factors which in turn can induce dysbiosis, an imbalance in the composition of the intestinal microflora. Clostridial enterotoxemia is an example of an undesirable change in the composition of flora flavoring Gram-positive toxigenic Clostridium spp. including Cl. perfringens and Cl. colinum in poultry with other clostridial counterparts in mature swine.

Prebiotics

Applying the definition of the pioneer
in the field of prebiotic therapy, Marcel
Roberfroid defined the class of com-
inclusion of this prebiotic to diets can re-
duce both the incidence rate and severity
of clostridial enterotoxemia.

Enzymes, probiotics and prebiotics have the potential to enhance productivity and economic return.

pounds as “selectively fermented ingredients that allow specific changes in the composition and activity of microflora in the intestinal tract conferring benefits to the host.” Prebiotics are complex carbohydrates with the fructooligosaccharides (FOS) and the mannonoligosaccharides (MOS), the most frequently encountered commercial forms.

The latter are usually derived from the outer cell wall of the yeast Saccharomyces cerevisiae. Mannonoligosaccharides have a multiple function in the intestinal tract. Apart from stimulating the proliferation of beneficial flora such as the Lactobacillus spp. and Bifidobacterium spp. MOS can selectively agglutinate organism with Type 1 fimbriae. It has been demonstrated that most of the Salmonella spp. and some other pathogens which bind to the mannan receptocytes on enterocytes can be cleared from the intestinal tract by addition of MOS to diets. There are also direct or indirect actions on immune regulation within the intestinal tract, enhancing the response to pathogens. Although MOS has no direct effect on Clostridum spp.

use of either prebiotics or probiotics or their combination will depend on intercurrent flock health which in turn is a function of housing, equipment, management, biose-curity, vaccination and microclimate.

Appraisal

Enzymes, probiotics and prebiotics have the potential to enhance productivity and economic return. Inexorably AGPs are being subject to greater legislative scrutiny resulting in restrictions and consumer rejection.

Alternatives including the three classes of alternative compounds must be shown by appropriate scientific protocols to be both effective and safe. Products should be supplied by reputable companies and should be supported by technical and analytical services. Price is of less importance than efficacy in order to obtain a desirable benefit to cost ratio. [FM]