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Guidance on the assessment of the efficacy of feed additives

2018; Wiley; Volume: 16; Issue: 5 Linguagem: Inglês

10.2903/j.efsa.2018.5274

1831-4732

Guido Rychen, Gabriele Aquilina, Giovanna Azimonti, Vasileios Bampidis, Maria de Lourdes Bastos, Georges Bories, Andrew Chesson, Pier Sandro Cocconcelli, Gerhard Flachowsky, Jürgen Gropp, Boris Kolar, Maryline Kouba, Marta López‐Alonso, Secundino López Puente, Alberto Mantovani, Baltasar Mayo, Fernando Ramos, Maria Saarela, Roberto Edoardo Villa, Robert John Wallace, Pieter Wester, Montserrat Anguita, Jaume Galobart, Matteo Lorenzo Innocenti, Laura Martino,

Animal Nutrition and Physiology

EFSA JournalVolume 16, Issue 5 e05274 GuidanceOpen Access Guidance on the assessment of the efficacy of feed additives EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)Search for more papers by this authorGuido Rychen, Guido RychenSearch for more papers by this authorGabriele Aquilina, Gabriele AquilinaSearch for more papers by this authorGiovanna Azimonti, Giovanna AzimontiSearch for more papers by this authorVasileios Bampidis, Vasileios BampidisSearch for more papers by this authorMaria de Lourdes Bastos, Maria de Lourdes BastosSearch for more papers by this authorGeorges Bories, Georges BoriesSearch for more papers by this authorAndrew Chesson, Andrew ChessonSearch for more papers by this authorPier Sandro Cocconcelli, Pier Sandro CocconcelliSearch for more papers by this authorGerhard Flachowsky, Gerhard FlachowskySearch for more papers by this authorJürgen Gropp, Jürgen GroppSearch for more papers by this authorBoris Kolar, Boris KolarSearch for more papers by this authorMaryline Kouba, Maryline KoubaSearch for more papers by this authorMarta López-Alonso, Marta López-AlonsoSearch for more papers by this authorSecundino López Puente, Secundino López PuenteSearch for more papers by this authorAlberto Mantovani, Alberto MantovaniSearch for more papers by this authorBaltasar Mayo, Baltasar MayoSearch for more papers by this authorFernando Ramos, Fernando RamosSearch for more papers by this authorMaria Saarela, Maria SaarelaSearch for more papers by this authorRoberto Edoardo Villa, Roberto Edoardo VillaSearch for more papers by this authorRobert John Wallace, Robert John WallaceSearch for more papers by this authorPieter Wester, Pieter WesterSearch for more papers by this authorMontserrat Anguita, Montserrat AnguitaSearch for more papers by this authorJaume Galobart, Jaume GalobartSearch for more papers by this authorMatteo Lorenzo Innocenti, Matteo Lorenzo InnocentiSearch for more papers by this authorLaura Martino, Laura MartinoSearch for more papers by this author EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)Search for more papers by this authorGuido Rychen, Guido RychenSearch for more papers by this authorGabriele Aquilina, Gabriele AquilinaSearch for more papers by this authorGiovanna Azimonti, Giovanna AzimontiSearch for more papers by this authorVasileios Bampidis, Vasileios BampidisSearch for more papers by this authorMaria de Lourdes Bastos, Maria de Lourdes BastosSearch for more papers by this authorGeorges Bories, Georges BoriesSearch for more papers by this authorAndrew Chesson, Andrew ChessonSearch for more papers by this authorPier Sandro Cocconcelli, Pier Sandro CocconcelliSearch for more papers by this authorGerhard Flachowsky, Gerhard FlachowskySearch for more papers by this authorJürgen Gropp, Jürgen GroppSearch for more papers by this authorBoris Kolar, Boris KolarSearch for more papers by this authorMaryline Kouba, Maryline KoubaSearch for more papers by this authorMarta López-Alonso, Marta López-AlonsoSearch for more papers by this authorSecundino López Puente, Secundino López PuenteSearch for more papers by this authorAlberto Mantovani, Alberto MantovaniSearch for more papers by this authorBaltasar Mayo, Baltasar MayoSearch for more papers by this authorFernando Ramos, Fernando RamosSearch for more papers by this authorMaria Saarela, Maria SaarelaSearch for more papers by this authorRoberto Edoardo Villa, Roberto Edoardo VillaSearch for more papers by this authorRobert John Wallace, Robert John WallaceSearch for more papers by this authorPieter Wester, Pieter WesterSearch for more papers by this authorMontserrat Anguita, Montserrat AnguitaSearch for more papers by this authorJaume Galobart, Jaume GalobartSearch for more papers by this authorMatteo Lorenzo Innocenti, Matteo Lorenzo InnocentiSearch for more papers by this authorLaura Martino, Laura MartinoSearch for more papers by this author First published: 07 May 2018 https://doi.org/10.2903/j.efsa.2018.5274Citations: 225 Correspondence: feedap@efsa.europa.eu Requestor: EFSA Question number: EFSA-Q-2017-00246 Panel members: Gabriele Aquilina, Giovanna Azimonti, Vasileios Bampidis, Maria de Lourdes Bastos, Georges Bories, Andrew Chesson, Pier Sandro Cocconcelli, Gerhard Flachowsky, Jürgen Gropp, Boris Kolar, Maryline Kouba, Marta López-Alonso, Secundino López Puente, Alberto Mantovani, Baltasar Mayo, Fernando Ramos, Guido Rychen, Maria Saarela, Roberto Edoardo Villa, Robert John Wallace and Pieter Wester. Acknowledgements: The Panel wishes to thank the members of the Working Group on Guidance update for the preparatory work on this scientific output. Note: The type of output indicated in the document has been modified from 'Scientific Opinion' to 'Guidance'. To avoid confusion, the original version of the Guidance has been removed from the EFSA Journal, but is available on request, as is a version showing all the changes made. Adopted: 17 April 2018 This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2018.EN-1411/full Updated: 28 June 2018 AboutSectionsPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract This guidance document is intended to assist the applicant in the preparation and the presentation of an application, as foreseen in Article 7.6 of Regulation (EC) No 1831/2003, for the authorisation of additives for use in animal nutrition. It specifically covers the assessment of the efficacy of feed additives. Draft Endorsed by the FEEDAP Panel 28 November 2018 Submitted for public consultation 4 December 2017 End of public consultation 28 January 2018 Adoption by the FEEDAP Panel 17 April 2018 Implementation date 1 September 2018 Background and Terms of reference Regulation (EC) No 1831/20031 establishes the rules governing the Community authorisation of additives for use in animal nutrition. Moreover, Regulation (EC) No 429/20082 provides detailed rules for the implementation of Regulation (EC) No 1831/2003 as regards the preparation and the presentation of applications and the assessment and the authorisation of feed additives. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) has adopted a series of guidance documents which aim at complementing Regulation (EC) No 429/2008 to support applicants in the preparation and submission of technical dossiers for the authorisation of additives for use in animal nutrition according to Regulation (EC) No 1831/2003. The European Food Safety Authority (EFSA) asked its FEEDAP Panel to: identify from the current guidance documents, those that need to be updated, taking into consideration the most recent scientific developments and the experience gained in the assessment of feed additives; update the guidance documents in need of revision accordingly; this activity can be conducted in different rounds of activities on the basis of the priorities identified and on the feasibility of the revision according the resources available; taking into account the sensitivity and the relevance of some of the guidance documents under revision and the entity of the revision itself (e.g. substantial or not), consider initiatives like preparatory info-sessions or public consultations of the draft guidance documents. The relevant comments received in either step will have to be considered and addressed if appropriate in the final version of the guidance documents. The first of the terms of reference was addressed by a statement of the FEEDAP Panel (EFSA FEEDAP Panel, 2016), in which it was identified the need to update most of the guidance documents that it produced and set priorities for this update. This output addresses the second and third terms of reference with regards to the update of the guidance documents dealing with the assessment of the efficacy of feed additives. This guidance document underwent a public consultation (EFSA, 2018). Scope of the guidance This guidance document is part of a series of documents intended to assist the applicant in the preparation and the presentation of its application for the authorisation of a feed additive, as foreseen in Article 7.6 of Regulation (EC) No 1831/2003. This document does not substitute for the obligation of an applicant to comply with the requirements of Regulation (EC) No 1831/2003 and its implementing rules (Commission Regulation No 429/2008). This document is intended to provide guidance to applicants for the assessment of the efficacy of additives intended to be used in animal feed, in order to demonstrate compliance with the requirements of Article 5.3 of Regulation (EC) No 1831/2003. This guidance is divided into seven sections. The first section provides the principles of the assessment of efficacy. The requirements for efficacy demonstration for the different categories of additives are listed in Section 2. Section 3 provides information on the number of efficacy studies required for those additives for which in vivo studies are needed. Sections 4 and 5 describe the principles for in vivo and in vitro studies, while Sections 6 and 7 provide information on how to report the studies performed by the applicant or those retrieved from the literature. Applicants should justify the omission from the dossier of any data or any deviations from the requirements detailed in this guidance. 1 General principles of efficacy assessment Regulation (EC) No 429/2008 requires that studies should demonstrate the efficacy for each proposed use and satisfy at least one of the characteristics set out in Article 5(3) of Regulation (EC) No 1831/2003, according to the categories and functional groups of feed additives as provided by Article 6 and Annex I of the said Regulation. Moreover, such studies must permit the evaluation of the efficacy of the additive according to common feed manufacturing, animal husbandry and farming practices in the European Union (EU). Studies performed outside the EU must permit conclusions to be drawn on the efficacy of the additive when used in the EU. This does not necessarily exclude the reporting of studies made outside the EU. Any potential impact on the distinctive features of animal products should also be investigated during animal efficacy trials (e.g. off-flavour, colour changes). All efficacy studies submitted should be properly reported and documented in order to allow an adequate assessment to be made. The studies should be based on the additive(s) for which authorisation is sought. To avoid confusion, in-house identifiers should be avoided unless embedded in third-party documents. In this case, a statement is required to confirm that the identifier(s) refers to the additive(s) concerned. However, the Panel considers that there are some additives for which efficacy is recognised (e.g. many nutritional additives and flavouring compounds). These additives do not require further demonstration of efficacy. For others, it is not practical to assess the additive under all possible conditions of use. Many factors may affect the efficacy of an additive, e.g. nutrition, animal breeds, composition of feed, management, environment, husbandry. For such additives, the Panel is able to conclude on the efficacy under the conditions of the studies submitted. From these data, the Panel may be able to conclude on the potential efficacy of the additive under EU farming conditions. As a general principle, efficacy can be assessed by means of in vitro studies for those additives which are intended only to affect the characteristics of feed (i.e. some technological and sensory additives), while for those which are intended to have an effect in the animal efficacy should be assessed by means of in vivo studies or, in specific circumstances, by a combination of in vitro and in vivo studies. The number of studies required to support the efficacy of an additive will depend on the nature of the intended effect(s) and the conditions of use of the additive (e.g. target species/categories). The studies should be based on the additive(s) for which authorisation is sought. Efficacy should be investigated by comparison of the lowest recommended dose with a control group and designed to allow statistical evaluation. Reference can be made to published studies to fulfil the requirements listed in the guidance provided that the active substance/agent in literature studies is identical to that under application or, if not, would still allow conclusions on the additive under application to be made. Attention should also be paid to known or potential biological or physico-chemical interactions between the additive, other additives and/or veterinary medicines and/or components of the diet, where this is relevant to the efficacy of the additive concerned, e.g. compatibility of a microbial additive with coccidiostats and histomonostats or organic acids. For details on how to perform compatibility studies between microbial additives and other additives showing antimicrobial activity, see the guidance on the characterisation of microorganisms used as feed additives or as production organisms. Studies involving animals should respect the rules on animal welfare laid down by EU legislation, particularly those listed in Directive 63/2010/EU. 2 Requirements for the different categories of additives 2.1 Technological additives When the additive is already authorised for use in food and the intended use of the additive in feed is the same, no further demonstration of efficacy is generally necessary provided that the effect seen when used in food could reasonably be expected to be seen when used in feed at the recommended concentration and that food and feed matrices are of comparable nature. 2.1.1 Technological additives which exert their function in feed For technological additives intended to affect the characteristics of feed, evidence of the efficacy should be demonstrated using laboratory-based studies by means of appropriate criteria as reflected in recognised acceptable methods, under the intended practical conditions of use in comparison with appropriate control feed. The studies (at least three) should be designed to cover a representative range of feeds to which the additive will be applied including water for drinking if appropriate. The appropriate endpoints are indicated in Table 1 for the various functional groups. Table 1. Demonstration of efficacy for technological additives exerting their effect in feed Functional group Demonstration of efficacy Preservatives Inhibition of the growth of spoilage microorganisms. Duration of the study should cover the period for which an effect is claimed. Test materials could be naturally or artificially contaminated. Antioxidants Protection against oxidative damage of key nutrients/components during feed processing and/or storage. The period for which a protective effect is claimed should be demonstrated. Emulsifiers Formation/maintenance of stable emulsions of otherwise immiscible or poorly miscible feed ingredients. Stabilisers Maintenance of the physico-chemical state of feedingstuffs, including the use of coating agents. Thickeners Viscosity of the feed materials or feedingstuffs. Gelling agents Formation of a gel resulting in a change in the texture of the feed. Binders Pellet durability (hardness, abrasion) or energy consumed during pellet formation. Anti-caking agents Flowability (angle of repose, frictional forces, compressibility). Acidity regulators pH and/or buffering capacity in feedingstuffs and/or water. Silage additives Improved production of silage (better preservation of nutrients). Inhibition of undesirable microorganisms. Reduction of effluents. Improved aerobic stability. Denaturants Indelible identification of feed materials. Hygiene condition enhancers Reduction of contamination with specific microorganism(s) relevant to feed safety (e.g. potential human or animal enteropathogens or undesirable bacteria). For other technological additives, the endpoints used to assess the function/effect of the additive should be defined and justified. 2.1.1.1 Silage additives For additives intended for the preparation of silage from all forages, a minimum of three separate tests should be made including one example of each of the following categories; – Easy to ensile forage: > 3% soluble carbohydrates in the fresh material; – Moderately difficult to ensile forage: 1.5–3.0% soluble carbohydrates in the fresh material; – Difficult to ensile forage: < 1.5% soluble carbohydrates in the fresh material. For additives intended for the preparation of silage from specific subcategories of forage described in terms of dry matter, the dry matter range should be explicitly stated. Three tests should then be made with material representative of the claimed range, where possible using examples of different botanical origin. Claims restricted to, or including, feedingstuffs other than forages, require tests specific to the particular feedingstuffs. All studies should demonstrate efficacy in comparison to a negative control made with the same material for ensiling. As a general guide, all replicate tests should be made with approximately 1 kg or more of homogeneous fresh material in a closed laboratory silo with the potential to vent gas and drain effluent. Other test systems (e.g. wrapped bales) may be used provided that they are consistent with the claims made and meet the general requirements above (including negative controls). The harvesting and preparation of the test material must be similar to normal practice. Compaction in the silos should be constant across replicates. The duration of the study normally should be 90 days or longer at a constant temperature (recommended range 15–25 °C). Use of a shorter duration must be justified. Claims made for silage additives differ and may relate to the preservation process in general, to specific aspects of the preservation process or to the aerobic stability of silage once the clamp/silo has been opened. The observations needed to demonstrate a significant benefit for the lowest dose claimed will differ both in nature and sampling time and frequency. As a rule measurements of the following parameters should be provided in comparison to the negative control3: dry matter and calculated dry matter losses (corrected for volatiles); pH concentration of volatile fatty acids and lactic acid concentration of alcohols ammonia nitrogen In addition, other microbiological and chemical parameters should be included as appropriate to substantiate the specific claim made (e.g. numbers of clostridia, numbers of Listeria in silage for sheep). A claim for effluent reduction will be judged against the total volume of effluent produced over the entire experimental period taking into account the likely effect on the environment (e.g. ecotoxicity of the effluent, biological oxygen demand). Reduction of effluent production should be demonstrated directly. The duration of the study should normally be 50 days. Aerobic stability studies should be of at least 7 days duration after exposure to air and the additive should provide evidence of stability for at least 2 days longer than that shown by the untreated control. It is recommended that the experiment is made at an ambient temperature of 20°C and a rise in temperature of 3°C or more above background taken as indicative of instability. Temperature measures may be replaced by the measurement of CO2 production. The measurement of dry matter loss and direct counts of aerobic spoilage organisms may be used as supportive evidence of improved stability. 2.1.2 Technological additives which exert their function in the animal 'Substances for control of radionuclide contamination' and 'substances for the reduction of contamination of feed by mycotoxins' are not expected to exert their intended effect until after their ingestion by the animal. Therefore, the demonstration of efficacy should be based on in vivo studies. The appropriate endpoints are indicated in Table 2 for the two functional groups. Table 2. Demonstration of efficacy for technological additives exerting their effect in the animal Functional group Demonstration of efficacy Substances for the reduction of contamination of feed by mycotoxins Reduction of the absorption of mycotoxins. Increased excretion of mycotoxins. Degradation/transformation of mycotoxins. Reduced concentration of mycotoxins in food of animal origin. Substances for control of radionuclides Evidence of reduced contamination of food of animal origin. For other technological additives exerting their effect in the animal, the endpoints used for assessing the functionality of the additive should be defined and justified. 2.1.2.1 Substances for reduction of the contamination of feed by mycotoxins The mycotoxin(s) against which the additive will exert its function and the target species should be specified. A battery of in vitro studies should be submitted to provide evidence of the intended effect of the additive. However, in vitro studies do not sufficiently mimic the conditions in the digestive tract and the differences between target animals and their metabolism, to fully demonstrate efficacy under practical conditions and therefore should be supported by in vivo studies. A minimum of three independent4 in vivo studies (generally short term) performed in at least two different locations showing significant effects should be provided to demonstrate efficacy at the lowest recommended dose. For additives intended to be used in all terrestrial species, efficacy should be demonstrated in vivo in three major species (at least one study in each) representing different digestive systems (a poultry species, a non-ruminant mammal and a ruminant). In each case, the studies should include the animal category for which the lowest maximum content of the respective mycotoxin in feed is set in Directive 2002/32/EC or recommended in Commission Recommendation 2006/576/EC. For additives intended to be used in fish, specific studies in fish (preferably salmonids) are required. The target mycotoxin content in feed used in studies should not exceed the values given in Directive 2002/32/EC for aflatoxin B1 and in Commission Recommendation 2006/576/EC for deoxynivalenol, zearalenone, ochratoxin A and fumonisins B1+B2 for complete feedingstuffs for the respective animal species/category and in Commission recommendation 2013/165/EU for T-2 and HT-2. For mycotoxins without a maximum content established at EU level, the dietary levels chosen should not exert adverse effects in the target animals. As a source of mycotoxins, naturally contaminated feed materials are preferred. Alternatively, feed spiked with mycotoxins could be used if properly justified. An quantitative analysis of mycotoxins5 present in feed should be provided for each trial. The experimental design of studies should include at least two groups: one group fed the basal contaminated diet as such (control) and the other fed the same basal contaminated diet supplemented with the additive for which authorisation is sought. For mycotoxins without a maximum content set/recommended, and in order to ensure the absence of adverse effects at the concentrations of mycotoxins used, an additional control group should be included. In this group, the feed should be free of these mycotoxins6 and have, in general, the same composition as the feed given to the other two groups. In general, mycotoxin/metabolites excretion in faeces/urine, concentration in blood/plasma/serum, tissues or products (milk or eggs) or other relevant biomarkers should be taken as endpoints for the demonstration of efficacy. The endpoints should be selected according to the mycotoxin and target species and taking into account the availability of sensitive analytical methods validated for the specific matrices. Recommendations on the endpoints are given in Table 3. Zootechnical parameters should be reported but cannot be used for the demonstration of efficacy. Table 3. Most relevant endpoints/biomarkers for substances reducing the contamination of feed by mycotoxins Target mycotoxin(s) Most relevant endpoints Aflatoxin B1 Aflatoxin M1 in milk/egg yolk Deoxynivalenol DON/metabolites in blood serum Zearalenone Zearalenone + α- and β-zearalenol in plasma Excretion of zearalenone/metabolites Ochratoxin A Ochratoxin in kidney (or blood serum) Fumonisins B1 + B2 Sphinganine/sphingosine ratio in blood, plasma or tissues 2.1.2.2 Substances for control of radionuclide contamination For substances for control of radionuclide contamination, a similar approach to the one for substances for reduction of the contamination of feed with mycotoxins should be followed. However, a single study demonstrating positive effects would generally suffice to support the efficacy. 2.2 Sensory additives When the additive is already authorised for use in food and the intended use of the additive in feed is the same, no further demonstration of efficacy is generally necessary provided that the effect seen when used in food could reasonably be expected to be seen when used in feed at the recommended concentration and that food and feed matrices are of comparable nature. 2.2.1 For substances which, when fed to animals, add colour to food of animal origin A minimum of three independent in vivo studies showing significant effects should be provided to demonstrate efficacy for the relevant target species/categories. Evidence of efficacy can be provided by (i) reference to published studies, where the relationship between a particular substance and the colour of animal tissues/products is well documented or (ii) in vivo long- or short-term studies. Evidence should generally be provided for each target species/category for which the application is made. The change in colour of tissues/products obtained from animals receiving the additive should be measured using appropriate methodologies (e.g. colour fan, reflectance spectroscopy, image analysis). 2.2.2 For substances that add or restore colour in feedingstuffs Evidence of the efficacy of the additive should be demonstrated using laboratory-based studies by means of appropriate criteria as reflected in recognised acceptable methods, under the intended practical conditions of use in comparison with an appropriate control feed. The change in colour of feed materials and/or compound feeds should be measured using appropriate methodologies (e.g. reflectance spectroscopy, image analysis). The studies (at least three) should be designed to cover a representative range of feeds to which the additive will be applied. The additive should not adversely affect feed quality. 2.2.3 For substances which favourably affect the colour of ornamental fish and birds Evidence of efficacy can be provided by (i) reference to published studies, where the relationship between a particular substance and the colour of the animals has been established or (ii) extrapolation of the colouring effect established in poultry or salmonids, as appropriate or (iii) in vivo studies in the target species. For (i) or (iii), a minimum of three independent long-term in vivo studies showing significant effects should be provided. The change in colour of animals receiving the additive should be demonstrated. 2.2.4 Flavouring compounds Evidence of efficacy can be provided by (i) reference to literature or (ii) laboratory-based studies (e.g. sensory panel, electronic nose) or (iii) if the application includes an effect on palatability, by short-term in vivo studies. For (iii), a minimum of three independent studies showing significant effects should be provided for each target species/category for which the application is made. 2.3 Nutritional additives No evidence of efficacy is necessary for amino acids naturally occurring in proteins of plants and animals and their salts, urea and vitamins, provitamins and compounds of trace elements.7 Evidence of efficacy should be provided for amino acid analogues, new forms of compounds of trace elements, chemically well-defined substances having similar effect to vitamin and urea derivatives. Evidence can be provided by reference to literature or by in vivo studies. Where evidence from literature is insufficient to reach a conclusion, a bioequivalence study is considered adequate to demonstrate efficacy for amino acid analogues, new forms of compounds of trace elements and urea derivatives. For chemically well-defined substances having similar effect to vitamin, duration and the endpoints of the in vivo study should be determined depending on the nature of the substance and the effect intended. For other (novel) nutritional additives at least one long-term efficacy study should be provided. Generally, it will be sufficient to demonstrate efficacy in one study in a single animal species or category including laboratory animals. For additives specifically designed to be effective in a particular animal species/category (e.g. protected amino acids for ruminan