Efficacy of the feed additive consisting of Bacillus velezensis NRRL B‐67259 (Correlink™ ABS1781) as a feed additive for all growing poultry species (Elanco GmbH)

Abstract

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of a product consisting of spores of Bacillus velezensis NRRL B‐67257 as a zootechnical additive for chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and minor poultry species. The additive has the tradename Correlink™ ABS1781 Bacillus subtilis and is not currently authorised in the EU. It is intended for use in complete feed for the target species at a minimum inclusion level of 1.5 × 10⁸ CFU/kg complete feed. In a previous opinion, the FEEDAP Panel could not conclude on the efficacy of the additive for the poultry species due to the potential cross‐contamination of the control diets in two of the three studies provided. The applicant has provided supplementary information to exclude this possibility. The new data showed that the gene used as marker in the previous analyses is non‐specific of the NRRL B‐67259 strain, which precluded the adequate quantification of the active agent in the feeds used in the studies. Moreover, in a second analysis, the active agent could not be isolated from the field excreta samples collected from either the treated or the control group in the two formerly submitted efficacy studies. The Panel concluded that the methodology was not able to discriminate between the strain under assessment and the background. Additionally, two new efficacy trials with chickens for fattening were provided to support the efficacy of the additive. However, none could be further considered since the husbandry conditions in which the birds were kept were non‐compliant with Directive 2007/43/EC. Therefore, the FEEDAP Panel was not in the position to conclude on the efficacy of Correlink™ ABS1781 for all growing poultry species.

1. Introduction

1.1. Background and Terms of Reference as provided by the requestor

Regulation (EC) No 1831/2003 establishes the rules governing the Community authorisation of additives for use in animal nutrition and, in particular, Article 9 defines the terms of the authorisation by the Commission.

The applicant, Elanco GmbH, is seeking a Community authorisation of Bacillus subtilis ABS1781 (Bacillus velezensis NRRL B‐67259) as a feed additive to be used as a gut flora stabilisers for chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and minor poultry species. (Table 1).

Table 1.

Description of the substances

Category of additive	Zootechnical additives
Functional group of additive	Gut flora stabilisers
Description	Bacillus subtilis ABS1781 (Bacillus velezensis NRRL B‐67259)
Target animal category	Chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and minor poultry species
Applicant	Elanco GmbH
Type of request	New opinion

On 30 September 2020, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) of the European Food Safety Authority (EFSA), in its opinion on the safety and efficacy of the product, could not conclude on the efficacy of Bacillus subtilis ABS1781 (Bacillus velezensis NRRL B‐67259) for the target species and regarding the compatibility with monensin, lasalocid salinomycin, narasin, robenidine and maduramicin, due to lack of data.

The Commission gave the possibility to the applicant to submit supplementary information and data in order to complete the assessment and to allow a revision of the EFSA's opinion. The new data have been received on 15 November 2021.

In view of the above, the Commission asks the Authority to deliver a new opinion on Bacillus subtilis ABS1781 (Bacillus velezensis NRRL B‐67259) as a feed additive for chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and minor poultry species based on the additional data submitted by the applicant, in accordance with Article 29(1)(a) of Regulation (EC) No 178/2002.

1.2. Additional information

The additive under assessment is a preparation containing viable spores of B. velezensis NRRL B‐67259. It has not been previously authorised in the EU.

2. Data and methodologies

2.1. Data

The present assessment is based on data submitted by the applicant in the form of supplementary information1 to a previous application on the same product.2

In accordance with Article 38 of the Regulation (EC) No 178/20023 and taking into account the protection of confidential information and of personal data in accordance with Articles 39 to 39 e of the same Regulation, and of the Decision of EFSA's Executive Director laying down practical arrangements concerning transparency and confidentiality,4 a non‐confidential version of the supplementary information has been published on Open.EFSA.5

2.2. Methodologies

The approach followed by the FEEDAP Panel to assess the safety and the efficacy of Bacillus velezensis NRRL B‐67259 (Correlink™ ABS1781 Bacillus subtilis) is in line with the principles laid down in Regulation (EC) No 429/20086 and the relevant guidance documents: Guidance on the assessment of the efficacy of feed additives (EFSA FEEDAP Panel, 2018a) and Guidance on the characterisation of microorganisms used as feed additives or as production organisms (EFSA FEEDAP Panel, 2018b).

3. Assessment

Correlink™ ABS1781 Bacillus subtilis (hereafter Correlink™ ABS1781) is a preparation of viable spores of B. velezensis NRRL B‐67259 intended for use as a zootechnical additive (functional group: gut flora stabilisers) in feed for chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and minor growing poultry species at the minimum concentration of 1.5 × 10⁸ CFU/kg complete feedingstuffs.

In its previous opinion (EFSA FEEDAP Panel, 2020), the FEEDAP Panel concluded that the additive is safe for the target species, consumers and the environment, that it is not irritant to skin and eyes or a skin sensitiser, but it is a respiratory sensitiser. However, the data provided were not sufficient to conclude on the efficacy of the additive for all poultry species. Moreover, the compatibility of B. velezensis NRRL B‐67259 with diclazuril, decoquinate and halofuginone was established, but not with monensin, salinomycin, narasin, robenidine, maduramicin and lasalocid.

The applicant has provided new information to address the gaps identified in the assessment of the efficacy of the additive which are the subject of this assessment.

3.1. Efficacy

In the former opinion, three efficacy studies conducted in chickens for fattening were submitted to support the efficacy of the additive. However, two of them could not be further considered due to the contamination of the control diets with the additive under assessment. In one study, the total bacilli counts in the diets of the control and treated groups were equivalent (i.e. control: 0.7/0.4/0.9 × 10⁸ CFU/kg feedingstuffs vs. Correlink™ ABS1781: 1.4/1.1/0.8 × 10⁸ CFU/kg feedingstuffs, in the starter, grower and finisher diets respectively). The presence of the active agent in all diets was confirmed by analysis using a polymerase chain reaction (PCR) targeting a functional gene of B. velezensis NRRL B‐67259 (■■■■■) which the applicant declared to be strain specific. Therefore, it was inferred that the control diets were contaminated with the additive. Similarly, equivalent total bacilli counts in the control and treated diets were found in the second study (i.e. control: 0.3/0.3/0.4 × 10⁸ CFU/kg feedingstuffs vs. Correlink™ ABS1781: 1.7/3.2/4.0 × 10⁸ CFU/kg in the starter, grower and finisher diets, respectively), but the presence of B. velezensis NRRL B‐67259 could not be confirmed due to the lack of samples. However, considering the similarities between the studies (i.e. they were both run in the same site and with the same design), and since B. velezensis NRRL B‐67259 was identified in excreta samples collected from both control and treated groups using the same PCR method, the possibility that the control diets of this study were also contaminated with the additive could not be excluded. Therefore, the Panel considered that there were insufficient data to conclude on the efficacy of Correlink™ ABS1781 for chickens for fattening.

In the current application, two sets of data have been provided. The first aims to justify previous findings in the above‐mentioned studies. The second set of data includes two new efficacy studies. Both are described below.

3.1.1. Data supporting previous findings

In the first set of data, the applicant declared that the ■■■■■ gene is not present only in the NRRL B‐67259 strain but can also be found in other bacilli and provides some data to support it. To determine the prevalence of the ■■■■■ gene among bacilli, ■■■■■ Therefore, it can be concluded that the ■■■■■ gene is non‐specific of the NRRL B‐67259, and this precludes the adequate quantification of the strain in the samples.

Furthermore, two additional experiments were conducted with excreta samples from the above‐cited trials to determine whether B. velezensis NRRL B‐67259 could be detected after the gastrointestinal (GI) tract transit and to assess the genetic relatedness of strains recovered from the excreta samples, with the final aim of excluding the cross‐contamination of control diets.8

■■■■■

■■■■■

■■■■■

The Panel has some doubts on the methodology applied ■■■■■.

The Correlink™ ABS1781 active agent could not be substantially and consistently isolated from the field excreta samples collected from the treated (inoculated with the active agent) or control birds. These findings would suggest that either the Correlink™ ABS1781 strain was not included in the correct way in the treated feeds, or the strain was not able to survive the chickens' GI tract transit and/or the analysis was not able to discriminate between the strain under assessment and the background.

3.1.2. New efficacy studies

Two new efficacy studies with an experimental design similar to the ones previously submitted have been provided to support the efficacy of Correlink™ ABS1781. However, none was further considered as the total bacilli counts in most of the starter, grower and finisher diets fed to the birds in the control and treated groups were equivalent, suggesting a potential cross‐contamination ■■■■■ 11 ■■■■■ 12 ■■■■■ 13 ■■■■■ 14 ■■■■■ Additionally, the husbandry conditions in which the birds were kept were not in line with Directive 2007/43/EC (e.g. used litter as bedding).

3.1.3. Conclusions on efficacy

With the data provided, it was not possible to draw any conclusion on the efficacy of Correlink™ ABS1871 for chickens for all growing poultry species.

4. Conclusions

The FEEDAP Panel is not in the position to conclude on the efficacy of Correlink™ ABS1781 for chickens for all growing poultry species.

5. Documentation provided to EFSA/Chronology

Date	Event
28/10/2021	Dossier received by EFSA. Correlink™ (Bacillus subtilis ABS1781) for chickens for fattening, turkeys for fattening, chickens reared for laying, turkeys reared for breeding, minor poultry species. Submitted by Elanco GmbH
29/03/2022	Reception mandate from the European Commission
28/06/2022	Acceptance mandate from the European Commission by EFSA – Start of the scientific assessment
21/07/2022	Request of supplementary information to the applicant in line with Article 7(3) of Commission Regulation (EC) No 1304/2003 for 178 – Scientific assessment suspended. Issues: efficacy
08/08/2022	Reception of supplementary information from the applicant – Scientific assessment re‐started
22/11/2022	Opinion adopted by the FEEDAP Panel. End of the Scientific assessment

Abbreviations

CFU

colony forming unit

FEEDAP

EFSA Scientific Panel on Additives and Products or Substances used in Animal Feed

Suggested citation: EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed) , Bampidis V, Azimonti G, Bastos ML, Christensen H, Dusemund B, Fašmon Durjava M, Kouba M, López‐Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Prieto M, Anguita M, Pettenati E, Rossi B and Brozzi R, 2022. Scientific Opinion on the efficacy of the feed additive consisting of Bacillus velezensis NRRL B‐67259 (Correlink™ ABS1781) as a feed additive for all growing poultry species (Elanco GmbH). EFSA Journal 2022;20(12):7711, 7 pp. 10.2903/j.efsa.2022.7711