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Feed additives and how they can be classified

Hops (left) and peppers (right) provide ingredients that can well be used as raw materials in feed additives.

The market is full of feed additives, making it often difficult to distinguish which does what and to what extent beneficial effects on animals have been tested, tried and researched. The European Commission plays its own role in this respect by classifying all additives for their function and quality.

By Dr Antje Holthausen, senior product manager, Delacon Phytogenic Feed Additives, Steyregg, Austria

The main reason for the re-organisation of the European Food and Feed legislative and the approval of the used feedstuff and feed additives is consumer safety and the protection of our environment. For the production of healthy food, the surveillance and regulation of feeding is an important part. Additives may only be used if they are evaluated by the EU Commission, approved and listed in the Register of Feed Additives pursuant to regulation (EC) No 1831/2003. In the new regulation and assessment of additives, an important step was the ban on antimicrobial growth promoters, which since 2006 has been in force in the EU. In many cases, the feed antibiotics have been replaced by the use of different antibiotics that are used for therapeutic purposes. The consequence is the increased development of resistance of various pathogens against more antibiotics that are subsequently missing for the therapy in human medicine.

To ensure the profitability of livestock production even without feeding antibiotics, innovative solutions in the prevention and optimal management are required. The positive effects of standardised mixtures of herbs, spices and extracts on animal performance, health and well-being are well established. Phytogenic feed additives are plantderived, natural, botanical compounds, comprised of herbs, spices and extracts. They are increasingly used in animal nutrition because they have beneficial biological effects, improve performance and are effective supports for livestock production. Nevertheless, there have been no phytogenic products whose performance-enhancing effects for the animal was acknowledged by the EU Commission.

Safety and efficacy
The regulation (EC) No 1831/2003 demands evaluation of additives for safety and efficacy before entry into the European feed additive register. Until this EU announcement all plant derived products currently available in the EU were premixtures of botanicaldefined compounds that are registered solely as flavouring substances. This allowed manufactures to only make claims based on feed palatability and intake. Animal health and performance claims were forbidden in the absence of documented proofs, and registration as a zootechnical additive. Feed additives are divided into groups,by function and effect:

  • Technological: Substance added to feed for technological purpose, e.g. emulsifiers, anticaking agents
  • Sensory: Substance which improves/ changes organoleptic properties of the feed or visual characteristics of the food derived from the animals, e.g. colorants or flavourings
  • Nutritional: e.g. vitamins, trace elements
  • Zootechnical: Additives which favourably influence the performance of animals in good health or the environment, e.g. digestibility enhancers
  • Coccidiostats and histomonostats The classification of feed additives into these groups is clearly connected to the beneficial claims that can be made by the authorisation holder.

The company Delacon Biotechnology is the first company which requested approval for one of its phytogenic products as zootechnical additive by the European Commission and also received it. The efficacy of Fresta F, applied at the minimum recommended dosage of 250 mg/kg feed, was evaluated in a total of five feeding trials with weaned piglets. The products mode of action enhances digestive processes, leading to improved nutrient utilisation and better growth. Extensive research and trials went into developing the product some years ago.

Trial results
Trial results showed that piglets fed with the phytogenic additive gained significantly more weight during the prestarter (+10.6 %) and starter period (+4.9 %), compared with the control groups (Figure 1). This was reflected in significantly higher body weights after the prestarter period (9.8 kg vs. 10.1 kg) and at the end of the experiment (23.3 vs. 24.2 kg). The supplementation also increased feed intake during prestarter and starter period (Figure 2) and improved feed conversion ratios, compared with control animals during the prestarter phase (improvement of 12.34 %), indicating improved nutrient utilisation.

Safety in the target animals was proven with a safety margin of five. This means that five times the maximum recommended dosage (2,000 mg/kg feed), is safe for performance and blood characteristics in weaned piglets. Consumer safety was confirmed by blood and meat analyses in piglets fed tenfold the maximum recommended dosage (4,000 mg/kg feed). The results clearly demonstrate that the product is safe for animals and consumers and improves zootechnical performance in weaned piglets.

As a result of the recent exacting safety, quality and efficacy evaluation by the European Food Safety Authority, the European Union Reference Laboratory, the EU Commission and 27 EU Member States, the feed additive was approved February 16th as a performance enhancing zootechnical feed additive. It is now the first and only phytogenic (plant derived, natural, botanical) product approved by the European Union as a zootechnical additive.

The potential of plant substances to enhance the performance of piglets as a safe alternative to antibiotic growth promoters could be shown by the approval. An examination of other plant derived products for safety and efficacy would be desirable to use the positive effects of phytogenic active ingredients and apply accordingly, thus continue to establish themselves as alternatives to antibiotics.

Plant derived compounds
The use of plant derived active compounds is for a major challenge the production of phytogenic feed additives. In addition to the clarification of the active ingredients and their combinations, the choice of raw materials is of great importance.

Raw materials vary considerably in the active concentrations depending on plant genetics, farming conditions, extraction technology, storage and processing. A careful selection of raw materials and comprehensive quality controls are essential for the production of consistent, standardised products. While for use in premixes a verification of active ingredient levels is not necessary, quality criteria for additives are more comprehensive. For the authorisation of an additive, evidence of contained active ingredients and their concentrations are important. Being able to standardise the quality active ingredients in phytogenic additives is a necessary criterion to guarantee the effectiveness of the product.