1. Introduction
The FSA and FSS have undertaken a safety assessment for a feed additive (Pediococcus pentosaceus DSM 32292 – Microferm Ltd., Spring Lane North, Malvern Link, Worcestershire, WR14 1BU, UK) under Assimilated Regulation (EC) No 1831/2003 (EC, 2003) under the category of ‘technical additives’ and functional group ‘silage additives’. The additive is proposed to be used in all animal species, with a proposed minimum content of 1 x 1010 CFU / g to be applied to silage at a minimum of 5 x 107 CFU / kg.
To support the safety assessment by FSA and FSS, the AFFAJEG and the ACAF provided advice to the FSA and FSS outlined in this document.
In line with Article 8 of 1831/2003, the assessment has considered whether the feed additive complies with the conditions laid down in Article 5, including: safety considerations for human, animal and environmental health; efficacy of the additive for its intended effect; potential impairment of the distinctive features of animal products. This, and the guidance put in place by EFSA for the evaluation of feed additive applications, has formed the basis and structure for the assessment.
The dossier was evaluated by the AFFAJEG at their May 2022 meeting and by the ACAF at their June 2023 meeting. Further information was provided by the applicant responding to queries by the FSA in June 2022, March 2023 and July 2023. The ACAF accepted the conclusions on this application at their April 2024 meeting.
The views of ACAF have been taken into account in this safety assessment which represents the opinion of the FSA/FSS.
2. Assessment
2.1. Section II: Identity, characterisation and conditions of use
The additive is formulated to contain viable cells of Pediococcus pentosaceus DSM 32292, sucrose (5%), skimmed milk powder (20%), and glycerine (3%). The conditions of use proposed by the applicant are listed in Table 2. The additive specification table information is located within Table 3.
In the first evaluation, the AFFAJEG identified several pieces of information that the applicant would need to provide to inform the assessment of the product, including microbial resistance gene information, laboratory accreditation certificates, an additive label, and physical properties data for the additive. These queries were satisfactorily addressed by the applicant. The additive is a significantly dusty product, and measures should be taken to limit exposure through inhalation.
2.1.1. Conclusions on Section II
The ACAF concluded the additive was correctly identified and characterised. The product is dusty. No further concerns were raised for Section II of this dossier.
2.2. Section III: Safety
The Committee noted that the active substance (Pediococcus pentosaceus DSM 32292) is a qualified presumption of safety (QPS) microorganism and as such no toxicological tests were required to evaluate the safety for the target species, consumers, or the environment.
The applicant noted that the product will be labelled as a respiratory sensitiser. The ACAF concluded the additive is likely to form a dust that could be inhaled by workers. As no studies of skin or eye irritancy or skin sensitisation were provided, the Committee regard the additive as potentially harmful by contact with skin or eyes.
2.2.1. Conclusions on safety
The AFFAJEG concluded that the additive can be considered safe for target species, consumers, and the environment. The additive is likely to form a dust that has the potential to be inhaled by workers. The additive should be considered a respiratory sensitiser and potentially harmful by contact with skin and eyes.
2.3. Section IV: Efficacy
The applicant provided studies on the effect that Pediococcus pentosaceus DSM 32292 had within three separate ensiling trials on ‘moderately difficult to ensile’ forages.
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Study A consisted of approximately 15 % perennial ryegrass, 60 % lucerne, 20 % red clover and 5 % herbs (mainly dandelion).
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Study B was composed of approximately 30 % grasses (mainly timothy, meadow fescue and perennial ryegrass), 60 % red clover, 5 % lucerne, and 5 % herbs (mainly dandelion).
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Study C consisted of approximately 25 % grasses (mainly timothy, meadow fescue and perennial ryegrass), 55 % red clover, 10 % white clover, and 10 % herbs (mainly dandelion).
The results demonstrated that the application of the P. pentosaceus inoculant improved the silage quality parameters pH, lactate, ethanol and 2,3-butanediol significantly in all three trials (Appendix A, Tables 4-6).
In the evaluation of the additive’s efficacy, the ACAF noted that the additive was only tested against a single class of forage. The Committee was able to conclude the additive was efficacious in moderately difficult to ensile forages. The Committee requested further information from the applicant however they were unable to provide studies within other classes of forage. Due to a lack of evidence the ACAF was unable to conclude on the additive’s efficacy in difficult to ensile forages.
2.3.1. Conclusions on efficacy
The Committee concluded that the additive is efficacious for moderately difficult to ensile forages. Due to a lack of evidence the ACAF was unable to conclude on the additive’s efficacy in difficult to ensile forages.
3. Analytical methods evaluation
Conclusions on the analytical methods are presented here as an extract from the Evaluation Report of the European Union Reference Laboratory for Feed Additives on the Method(s) of the Analysis for Pediococcus pentosaceus DSM 32292 (EURL-FA, 2020).
"For the identification of Pediococcus pentosaceus DSM 32292, the EURL recommends for official control (i) Whole Genome Sequencing Analysis (WGS) or (ii) Pulsed-Field Gel Electrophoresis (PFGE). The EURL considers that both methodologies are fit for purpose for the bacterial identification of authorised additives at a strain level.
For the enumeration of Pediococcus DSM 32292 in the feed additive, the EURL recommends for official control the ring-trial validated spread plate method EN 15786.
Since the unambiguous determination of the content of DSM 32292 initially added to silage is not achievable by analysis, the EURL cannot evaluate nor recommend any method for official control for the determination of Pediococcus pentosaceus DSM 32292 in silage."
FSA/FSS accepts the EURL analytical method evaluation reports. FSA/FSS determined the analytical method as appropriate for official controls for this feed additive.
4. Conclusions
The Committee concluded the additive was correctly identified and characterised. The additive shows a high dusting potential.
The ACAF concluded that the additive can be considered safe for target species, consumers, and the environment. The additive should be considered a respiratory sensitiser and potentially harmful by contact with skin and eyes.
The Committee concluded that the additive is efficacious for moderately difficult to ensile forages. Due to a lack of evidence the ACAF was unable to conclude on the additive’s efficacy in difficult to ensile forages.
The FSA/FSS agree with the conclusions reached by the AFFAJEG/ACAF. FSA/FSS accepts the EURL analytical method evaluation reports. FSA/FSS determined the analytical method as appropriate for official controls for this feed additive.
Acknowledgements
With thanks to the members of the AFFAJEG and ACAF during the course of the assessment, who were: Professor Nicholas Jonsson, Professor Emily Burton, Martin Briggs, Professor Katrina Campbell, Professor Matthew Fisher, Hannah Kane, Susan MacDonald, Dr. Oonagh Markey, Christine McAlinden, Dr. Donald Morrison, Derek Renshaw, Dr. Michael Salter, Dr. Adam Smith, Christel Wake, Dr. Helen Warren and Dr. Nick Wheelhouse.