The intensive livestock production and the spreading of high productivity genetic stocks, have conditioned the common use of chemical substances known as “growth promoters”.
This kind of molecules are added at low rate to animal feed without changing considerably its composition. They speed up the growth and consequently increase the body size and weight rate. In order to be effective, growth promoters must keep their integrity during digestion process and must not be absorbed to perform their function.
From among all molecules known as growth promoters, the most traditionally used are antibiotics, although nowadays, their use is decreasing up to total extinction.
This new situation in animal production has stimulated the research of new substances with the same finality as antibiotics, however without toxic effect for the consumer. This is the case of “pronutrients”.
A pronutrient is defined as a micro ingredient included in the formulation of animal feed in relatively small amounts with specific physiological and microbiological functions, different from any other nutrient. This definition corresponds with the description of the E.U about “ingredient for feed animal “.
Many active ingredients from plants must be considered pronutrientes and are included in the formulation of multiherbal products with growth promoter action. It is due to their effect against the colonization of different diarrhoeagenic enter pathogens (E. coli…) and their stimulation of beneficial bacteria, the probiotic bacteria.
Some of the most popular are: Holarrhena antidysenterica, Zingiber officinale, Aegle marmelos and Woodforida fructicosa.
Holarrhena antidysenterica, has been used in Europe and India for the treatment of dysentery. Around 30 different components have been isolated mainly from the bark. One of the most important is connesine, the active principle with antiprotozoal activity. Moreover, it has been checked the bactericidal action against enteric pathogen like S. aureus, S. typhimurium, E. coli….
The rhizome is the Zingiber officinale part plant used due to its properties. This plant contains a mixture of over 24 constituents, as gingerol, with purging activity. Zingiber is valued as stimulant to the gastro-intestinal tract, too.
The rind of the fruit of Punica granatum, is very useful in diarrhoea and dysentery and the root bark has been used as antihelmintic. The bark and rind of the fruit contain tannins and other kind of constituents as delphinidin diglycosido and malvidin pentosa glycoside.
According to British Pharmacopoeia, Aegle marmelos, has a therapeutic effect against diarrhoea and dysentery. Sterols, tannins and aromatic components as for example: marmelin, aegelin, umbelliferine… have been detected as main active components.
To conclude, the flowers Woodforida fructicosa are used for dysentery and diarrhoea containing high proportion of ellagic acid, the main active component.
All these pronutrients have a synergistic action and as a consequence, improve and increase the productive index, e.g. the Conversion Index. To summarize all of them:
- Stabilize the intestinal peristalsis, improving the intestinal transit time of nutrients (proteins, minerals, vitamins, electrolytes) though the lumen, allowing their optimal absorption.
- Contribute to the formation of a “gel extrusion matrix”. This “gel extrusion matrix” allows the separation of molecules of different sizes and improves the absorption of small molecules. Moreover this “gel”, acts as support for the growth of beneficial bacteria.
- Help the gas reabsorption.
- Optimise the intestinal mucosa.
Benefits of pronutrients have been studied since years before, and have been checked in different animal species:
- Das, M. K. and Maity, D. P. (1997) studied the efficacy with or without chemotherapeutics in calves. Livestock International, Dec. 19.
- Jani, R.G. and Patel, P. R. (1995) studied the effect in non-specific diarrhoea in goats. Pashudhan August 22.
- Kanaran, P.P; Vijayan, P (1990) studied the effect on cattle. Indian J. Indg. Med. 7: 39-41.
- Mukherjee, R (1998) studied the clinical efficacy in diarrhoeic piglets. Pashudhan 11 810) Oct: 20.
All this experiences have showed similar results: the use of natural pronutrients, presented in plant extracts, produce a decrease in the mortality rate, reduce the feed conversion rate and improve the feed cost per kg weight gain, being a healthy alternative to antibiotics.
