PHYTOBIOTICS: of poultry. The search is therefore


Phytobiotics can be defined as plant derived products added to
feed in order to improve performance. They originate from leaves, roots, tubers
or fruits of herbs, spices and other plants. They may be available in solid,
dried, and ground forms, or as extracts (essential oils).

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The economic and nutritional demands of our modern society for food from
poultry necessitate the raising of poultry under intensive production system in
densely populated colonies or flocks, which results in stress. Under such
circumstances, antimicrobial feed additives such as antibiotics are often used
to suppress or eliminate harmful microorganisms in the intestine and to improve
growth and feed efficiency. However, one major aspect of food production and
safety today is the reduction in the use of antibiotics and other medicinal
products in the poultry production largely due to fears over bacterial
resistance and possible transmission of these antibiotic residues into the
human food chain. During the last two decades considerable research has been
done on exploring the beneficial effects from the growth promoters and finding
suitable alternative to antibiotics. Research is also going on to find out more
such natural products to enhance the performance of poultry. The search is
therefore on for an economically viable alternative to the antibiotic growth
promoters (AGPs). A wide variety of substances are used in conjunction with, or
as alternatives to, AGPs in poultry diets. Probiotics, prebiotics and organic
acids have all shown promising results in controlling a wide array of bacteria
including Salmonella, Campylobacter, Clostridium and E. coli. The
phytogenic feed additives are a more recent addition in this list and are
composed of plant extracts (microencapsulated essential oils, bitter
substances, and pungent substances and may also include an acid substance and
saponin). These preparations have been shown to activate digestion, strengthen
the immune system and have antibacterial properties.




Phytobiotics may be explained as plant derived
products added to the feed in order to improve performance of agricultural
livestock. This definition addresses mainly the purpose of use in terms of a
feed additive to healthy animals under common practical conditions of
production of food of animal origin rather than the veterinary use for
prophylaxis and therapy of diagnosed health problems. According to this
definition, phytobiotics comprise of very wide range of substances with respect
to biological origin, formulation, chemical description and purity. Within this
variety, some subgroups may be classified, such as herbs (product from
flowering, non-woody and non persistent plants), botanicals (entire or
processed parts of a plant, e.g. root, leaves, bark), essential oils (hydro
distilled extracts of volatile plant compounds), and oleoresins (extracts based
on non-aqueous solvents). The active compounds of phytobiotics are secondary
plant constituents. Their primary mode of action is often not known sufficiently
to explain the final effects in vivo, especially since phytobiotics usually
contain mixtures of compounds with beneficial and potentially adverse effects,
depending on the nature and the dose of the respective substances.
Nevertheless, common knowledge from folk medicine and recent experiences from
feeding studies give significant rise to accept the principal potential of
phytobiotics to significantly improve zoo technical performance in agricultural
livestock. Phytobiotic preparations are the preparations of vegetative origin
as well as their chemical constituents, that positively effect the micro flora
of the digestive system. The phytochemical substances of the vegetative forage
are grouped according to their structure and activity in the organism as carotinoides,
poliphenoles, phytoestrogenes, sulphides and thioles, saponines and others. The
action of these substances in the organism is related to the suppression of the
degenerative processes. It is related to the anti-oxidative inhibition,
stimulation of the detoxicative enzymes, effect on the cells functions, binding
of the excess of some substances and the effect on the intestinal micro flora.
The substances of the vegetative origin saponines are able to bind cholesterol,
decrease its resorbtion and remove it from the organism; they also have
secretomotoric and secretolyticproperties, can enhance the immune system of the
animal and destroy the pathogenic micro-organisms.


roots, flowers and whole plants are used for production of phytobiotic
products. Products may comprise the dried form of whole plants or their parts
or extracts of some valuable ingredients. In general, phytobiotics are
described by primary and secondary plant compounds.

compounds are main nutrients (e.g., content of protein, fat, etc.), whereas,
secondary compounds comprise essential (ethereal) and/or volatile oils,
bitterns, hot stuffs, colorants and phenolic compounds. In general,
phytobiotics do not add significantly to the intake of main nutrients in
poultry. Therefore, secondary plant compounds are the main ingredients of
interest. The main constituents of essential oils are lipophilic, liquid and
volatile and belong to chemical groups of alcohols, aldehydes, esters, ethers,
ketones, phenols and terpenes. Some major constituents for rosemary, sage,
thyme, oregano and purple cone flower.

stimulate the digestive system and by this improve nutrient digestibility.
Furthermore, essential oils act against oxidative processes, and growth of
bacteria and moulds, both in the gastrointestinal tract (GIT) and in the feed.
Bitterns and hot stuffs are of less importance as most phytobiotics contain
only small amounts of these ingredients. Bitterns are reported for thyme and sage
(carnesol) and hot stuffs for chilli (capsaicin). It is well documented that
poultry is in favour of bitter taste, whereas, high contents of hot stuffs
result in feed rejection. Natural colorants (xanthophylls) are included in most
phytobiotics. The dominant xanthophylls are lutein, zeaxanthin, ?-carotene and
lycopene. In chillicapsanthin and capsorubin are responsible for the red

areantioxidants and show partly pro-vitamin A activity. Antoxidative capacity
of colorants is yet not very intensively investigated in poultry as the major
antioxidants in diets are selenium and vitamin E. Provitamin A activity is
normally of minor interest as commercial diets are supplemented with sufficient
amounts of vitamin A. Due to the normally low supplementation level of
phytobiotics to broiler diets the colouring effect is less pronounced. Various
phenolic compounds are included in phytobiotics with flavonoids and chicoric
acid being the dominating ones.

The pharmacological
effects of phenolic compounds are s