ZOOTECHNICAL FEED ADDITIVES: ENZYMES, PROBIOTICS AND PREBIOTICS — MODE OF ACTION | ||
| Veterinary Medical Journal (Giza) | ||
| Volume 57, Issue 3, July 2009, Pages 309-323 PDF (4.85 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/vmjg.2011.367834 | ||
| Author | ||
| Ortwin Simon | ||
| Institute of Animal Nutrition, Free University Berlin, Briimmerstrasse 34, D-14195 Berlin, Germany | ||
| Abstract | ||
| In practical use, two functional groups of zootechnical additives are of prime importance, i.e. digestibility enhancers and gut flora stabilizers. Within the first group, mainly enzymes having specificities for partial hydrolysis of cereal non-starch-polysaccharides (NSP-enzymes) and to release phosphorus from phytic acid (phytases) are authorised for the use as feed additives. Both NSP-enzymes, xylanases and β-glucanases, are capable to reduce digesta viscosity and to eliminate partially or completely the antrinutritive effects of NSP. Thus, the main scope of the use of NSP- enzymes is to eliminate the deleterious effects of antinutitive substances in chickens and piglets. Addition of microbial phytases to feed of poultry and pigs is highly effective in improving phosphorus availability from plant material. The main scope of the use of phytases is the increase of phosphorus digestibility through action on the target feed material. Furthermore, by using phytases as feed additive, it is possible to reduce the phosphorus pollution into the environment considerably. Selected micro – organisms (probiotics) are authorised as feed additives acting as “gut flora stabilizer”. Although the majority of studies on the effectiveness of probiotics in piglets point towards improved animal performance, these effects are rarely significant and not consistent. However, when the incidence of post weaning diarrhoea was recorded, in almost all studies, including different probiotic strains, as significant reduction was observed, Therefore, probiotics act primary as safety factors in a production system without antibiotic growth promoters rather than to replace antibiotics in terms of growth promoters. Any of the probiotic organisms are also authorized as additive in poultry feed. Prebiotics are defined as selectively fermented feed ingredients that allow specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host wellbeing and health. However, the effectiveness and the mode of action of prebiotics in farm animals are not well documented. | ||
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