Following the ban on antibiotic growth promoters (AGPs) in Europe, various solutions have come on to the market, with more or less documentation. The objective of such solutions must be to ensure a level of efficacy at least equivalent to that obtained with the products they are designed to replace, while preserving the animals physiology in an environmentally-friendly manner. One of these solutions, based on plant extracts, essential oils and spices, has been developed for poultry production. Its objectives are to optimise feed intake and the digestive process as a whole to maximise feed utilisation, as well as to control pathogen development in the digestive tract. Today, this natural solution has proven its value and numerous trials on broiler chickens and turkeys validate this innovative concept. These trials, conducted either in research stations or on commercial farms, demonstrate that this plant-based complex (Oleobiotec^®) helps to attain zootechnical performance similar to that obtained with antibiotic growth promoters, with a positive impact on poultry survival.

The complementary activities of essential oils and spices

In all animal production, performance and health are closely linked to nutrition, but also to the efficacy of the digestive process, responsible for the conversion of raw materials by the animal. If we are able to optimise this process, we can contribute to optimising farm performance. Based on this idea, we have developed a specific blend of essential oils and spices aimed at enhancing and securing poultry digestive functions. Thanks to their complementary activities, these essential oils (oregano, thyme, cinnamon) and spices (ginger, turmeric, pepper...) are able to act at various levels of the digestive process (Figure 1).

Figure 1: The different levels of action of the Oleobiotec complex in poultry digestion.

Why use essential oils?

Today, the bactericidal activity of certain essential oils is well known and many scientific publications have investigated their modes of action. One of the principal modes of action of essential oils with bactericidal properties is directed against microbial membranes and cell walls. This specificity confers upon them a large spectrum of activity, targeting gram+ and gram- bacteria, yeast or fungus, unlike most of the traditional antibiotics. When added continuously to the feed, the essential oils contained in Oleobiotec can help secure the digestive process and control the potential pathogenic microflora present in the digestive tract.

In vitro studies have shown that the activity of Oleobiotec against the main pathogens affecting poultry, coliforms, Campylobacter, S. thyphimurium, C. perfringens, was comparable to the efficacy of commonly used antibiotics. (Figure 2).

Figure 2: In vitro bactericidal activity of Oleobiotec vs. antibiotics against some common chicken pathogens (Laboratoire d'Hygiène Départemental du Tarn - France, 1999-2001)

Spices optimise the digestive process

In addition to their gustative qualities, spices are known for their effects on health and digestion. They are present in the traditional pharmacopoeia of many civilisations: chinese or ayurvedic medicine for instance. They were even used in Ancient Egypt for their medicinal properties. Today, many active compounds have been isolated from spices and characterised, such as piperine form peppercorn, 6-7-dihydrocapsaicin from pepper....Their modes of action are increasingly known. The blend of spices present in Oleobiotec has been specifically formulated for its activity at different levels of the digestive process, from feed intake to nutrients absorption in the gut:

1) At the level of the taste buds: activation of the heat receptors, which in turn stimulate:

          - the salivation (increased synthesis of amylases)
          - the secretion of digestive juices in the stomach
          - the secretion of gastric juices and mucus by the stomach epithelium
          - the secretion of bile and increase in the level of biliary acids in the gastric juices

2) At the stomach level: increased gastric motility
3) At the gut level: increased permeability of the gut mucosa to improve nutrient absorption.

By optimising the digestive process, the blend of spices contained in Oleobiotec helps improve feed valorisation.

Aromatic compounds to optimise ingestion

In order to optimise feed intake, some aromatic compounds were selected that have a positive impact on poultry.

Improved zootechnical performance in broiler chicken

Various trials were conducted in broiler chickens, both in a research station and on production sites in different European countries. Two meta-analysis were conducted:

1) In the first meta-analysis, the results of five trials with Oleobiotec were measured against the performance obtained with a growth promoter (avilamycine, 10 ppm ) -Table 1-.

Table 1: Details of the five trials used in the first meta-analysis

A natural alternative to poultry growth promoters - Image 3

2) The second meta-analysis compares the results of four trials with Oleobiotec against a negative control (table 2)

Table 2: Details of the four trials used in the second meta-analysis

A natural alternative to poultry growth promoters - Image 4

Statistical analysis was performed using the linear mixed model on the Oleobiotec-control variations (program SPSS, version 13.0, 2004). The observed data was weighted according to the inverse of the variance of the difference. The fixed effect component is the constant and the random effect component is the experiment. The information criterion is the restricted maximum likelihood.

Results of the two meta-analysis are summarised in Tables 3 & 4 below.

Table 3: Conclusions of the first meta-analysis: zootechnical performance with Oleobiotec vs. a growth promoter.

The zootechnical performances obtained with natural solution Oleobiotec are similar to those attained with an antibiotic growth promoter.

Table 4: Conclusion of the second meta-analysis: zootechnical performance with Oleobiotec vs. negative control

The addition of Oleobiotec to the feed of broiler chicken significantly improves growth rate and slaughter weight when compared to control feed.

Improved performance in turkeys

The results obtained in turkeys are similar to that of broiler chickens. Table 5 summarises the trial conditions and results for two experiments conducted in turkeys.

Figure 3 shows that Oleobiotec significantly increases turkeys live weight at twelve and twenty weeks, as compared to negative control or another feed additive based on essential oils.

When comparing Oleobiotec to negative control, some improvements were measured concerning the turkeys gastro-intestinal physiology:

- a significant decrease of jejunal pH
- a numerical decrease of ileac digestas viscosity
- a significant increase of alpha-glucosidase enzymatic activity in the ilium (table 6).

As observed with broiler chicken, Oleobiotec efficiency in improving performance and survival in turkeys is similar to that of antibiotic growth promoters.

Table 5 : Summary of two trials with Oleobiotec in turkey. (Phodé, 2005-2006)

A natural alternative to poultry growth promoters - Image 7

Figure 3: Effects of various feed additives on turkeys' growth performance (Poultry Department of University of Warmia and Mazury in Olsztyn, Pologne).

Table 6: Effetcs of Oleobiotec on turkey's gastro-intestinal physiology (Poultry Department of University of Warmia and Mazury, Olsztyn, Poland)

A natural alternative to poultry growth promoters - Image 9

Conclusion

It can be concluded from the results of these various trials that natural feed additive Oleobiotec, which combines the anti-bacterial properties of essential oils with that of the spices digestive qualities, enables the enhancement of growth performance in turkeys and broiler chickens (ADWG and live weight at slaughter). It also improves feed efficiency, resulting in optimal feed valorisation. Various trials have permitted us to measure these effects against those of antibiotic growth promoters. Over the past few years, the European poultry production market has evolved, driven by various constraints, both economical and regulatory (AGPs withdrawal, Salmonella regulations...), whilst also having to meet consumer expectations. In such a context, Oleobiotec appears to be a profitable and sustainable alternative that naturally optimises poultry performance.