Feed additives

1. Feed additives
growth promoters:
improve the production traits of healthy animals
• Antibiotics: produces by other microorganisms, fungi that protect the
growth of bacteria
– reduce the number of pathogenic bacteria (E. coli, Salmonella sp.,
etc.), prevent the infection of the digestive tract,
– increase the absorptive capacity of the small intestine (decrease the
thickness of the intestinal wall)
– reduce the competition of bacteria with the host (bacteria ferment the
nutrients before digestion)
– they have been used mainly in pig and poultry nutrition
– their widespread use could cause the ability of certain strains to be
resistant to many antibiotics
– therefore in the EU the use of antibiotic growth promoters has been
restricted since 2000

2. • Probiotics: live microbial food supplement
– containing mostly lactic acid producing bacteria
– by reducing the pH in the intestine, reducing the numbers of
harmful bacteria (competitive exclusion)
– enhance immune competence
– are heat sensitive (pelleting)

3. • Prebiotics: oligosaccharides (2-20 monosacharides)
that modify the balance of the microfloral population by
promoting the growth of the beneficial bacteria
– can be fermented by the favourable bacteria
– decreasing the attachment of harmful bacteria with the
gut wall
– galactooligosaccharides (GOS) (legume seeds)
– fructooligosaccharides (FOS) (cereal grains)
– mannanoligosaccharides (MOS) (yeast cell walls)

4. • Symbiotics: contain both probiotics and
prebiotics.
• Organic acids: (lactic acid, formic acid,
fumaric acid, citric acid, propionic acid etc.)
– stabilise the intestinal microflora by
decreasing the pH
– can be effective in early weaned, young
animals
– incorporated into the diet (6-25 g/kg) or
into the drinking water

5. • Enzymes:
– as a result of advances in biotechnology, more effective enzyme preparations
can be produced relatively inexpensively
– supplement the insufficient enzyme secretion of young animals (amylase,
protease, lipase etc.)
– can improve the availability of plant storage polysaccharides (starch, oils and
proteins) by degrading the cell wall content like cellulose by the enzyme
cellulase (5-10% improvement can be achieved in poultry and pig trials)
– destroy ant-nutritive materials that interfere with the digestion and utilisation
of nutrients (glucanase, xylanase destroy cereal cell wall compounds, β-
glucans and arabinoxylans)
– phytase releases phosphorous and other minerals from phytic acid in cereals
and oilseeds (greater availability of minerals, less need for inorganic
phosphorous, beneficial effect on the environment)
• Flavory materials: (sugars, vanilla, canella etc.)
– increase the feed intake
– can be effective mostly in young intensively growing animals
– their effect depends on the flavour sensation of different animal species

6. • Plant extracts, essential plant oils: (sage, peppermint, garlic, thyme etc.)
– can be used for the partial replacement of antibiotics
– complex effects (flavour materials, antimicrobial compounds,
antioxidants etc.)
– the products in the practice are mostly the mixture of different plant
extracts and oils
– their market share is increasing in Europe
Toxin binders: used for binding mycotoxins ; ochratoxin, aflatoxin etc.),
decrease their absorption
aluminium silicates (bentonit)
glucomannans (yeast cell wall extracts)
they efficiency is toxin dependent
bind also some minerals and nutrients

7. • crystallinene amino acids:
– L – lysine
– DL – methionine
– in the near future threonine, tryptophan and arginine will also be available in the
feed industry
–colour materials: carotenoids (zeaxanthin, lutein, licophin, capsanthin etc.)
– egg yolk
– skin, the fat below the skin
– using is synthetic colour compounds is limited in the EU
•antioxidants: protecting vitamins and fatty acids from the oxidation
– synthetic antioxidants
– etoxi-methil-quinolin (EMQ)
– butil-hidroxi-toluol (BHT)
– natural antioxidants (vit. E, vit. C, carotenes etc.)
– they need depends on the fat and unsaturated fatty acid content of the diet.