Safety and efficacy of a feed additive consisting of chromium chelate of dl‐methionine (Availa® Cr) for all finfish (Zinpro Animal Nutrition Europe, Inc.)

TL;DR

This paper evaluates the safety and effectiveness of a chromium chelate feed additive for finfish, finding it safe for salmonids but not conclusively for other species.

Contribution

The study provides a detailed safety and efficacy assessment of Availa® Cr for finfish feed, including consumer and environmental safety.

Findings

Availa® Cr is safe for salmonids at 600 mg additive/kg feed (0.6 mg Cr/kg feed).

The additive is not an eye or skin irritant but is a skin and respiratory sensitiser due to nickel.

The additive is potentially efficacious in salmonids at 0.2 mg Cr/kg feed and in other finfish at 0.5 mg Cr/kg feed.

Abstract

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a feed additive consisting of chromium chelate of dl‐methionine (Availa® Cr) for all finfish. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive is safe for salmonids at the maximum proposed use level of 600 mg additive/kg complete feed (corresponding to 0.6 mg Cr/kg complete feed). The FEEDAP Panel was not in the position to conclude on the safety of the use of Availa® Cr in feed for other finfish. The use of the additive in finfish feed at the maximum proposed use level was considered safe for the consumer and for the environment. Regarding user safety, the FEEDAP Panel concluded that the additive is not an eye nor skin irritant, but due to the presence of nickel, the additive is considered a skin and respiratory sensitiser. Inhalation and dermal exposure are considered a risk. The FEEDAP Panel concluded that the additive has the potential to be efficacious in salmonids at 0.2 mg Cr/kg complete feed, and in other finfish at 0.5 mg Cr/kg complete feed.

Tables

TABLE 1. Trial design and Cr content of the diets of the efficacy trials performed in other finfish.

Species	No of animals (animals/replicate) Replicates/group	Bodyweight (sex) duration	Tank size salinity light regime	Composition feed (form)	Groups (mg Cr/kg complete feed)
					Intended	Supplemented 1	Analysed (total)
Gilthead seabream	800 (50) 4	32 g (♂) 91 days	1000 L 35.5 g/L 14 hL:10 hD	Plant‐derived meals, poultry meal, fish meal 7.5% (pellets)	0 0.2 0.4 0.6	– 0.21 0.44 0.64	2.68 2.89 3.12 3.32
African catfish	800 (50) 4	54 g (ND) 84 days	60–120 L 0 g/L 24 hD	Plant‐derived meals, poultry meal, fish meal 15% (pellets)	0 0.2 0.4 0.6	– 0.51 0.96 1.10	2.37 2.88 3.33 3.47

TABLE 2. Effects of Availa® Cr on the productive performance parameters of other finfish.

Trial (species)	Groups	Feed intake	Final body weight	Specific growth rate	Feed to gain ratio	Mortality
	Supplemented mg Cr/kg complete feed	% body weight /day	g	% body weight /day		%
Gilthead seabream	0 0.2 0.4 0.6	1.53a 1.47b 1.45b 1.48b	126b 132a 135a 135a	1.51c 1.55b 1.58a 1.57a	1.16a 1.10b 1.08b 1.10b	0.5 0 0 0
African catfish	0 0.2 0.4 0.6	2.43 2.51 2.50 2.42	591b 684a 671a 634ab	2.83c 3.03a 2.99ab 2.92bc	0.86 0.81 0.84 0.83	2.5 3.0 4.0 3.5

Full text

INTRODUCTION

1

Background and Terms of Reference

1.1

Regulation (EC) No 1831/20031 establishes the rules governing the Community authorisation of additives for use in animal nutrition. In particular, Article 4(1) of that Regulation lays down that any person seeking authorisation for a feed additive or for a new use of a feed additive shall submit an application in accordance with Article 7.

The European Commission received a request from Zinpro Animal Nutrition Europe, Inc.2 for the authorisation of the additive consisting of chromium chelate of dl‐methionine (Availa® Cr), when used as a feed additive for all finfish (category: zootechnical additives; functional group: other zootechnical additives).

According to Article 7(1) of Regulation (EC) No 1831/2003, the Commission forwarded the application to the European Food Safety Authority (EFSA) as an application under Article 4(1) (authorisation of a feed additive or new use of a feed additive). The dossier was received on 26 August 2024, and the general information and supporting documentation are available at https://open.efsa.europa.eu/questions/EFSA‐Q‐2024‐00533. The particulars and documents in support of the application were considered valid by EFSA as of 06 January 2025.

According to Article 8 of Regulation (EC) No 1831/2003, EFSA, after verifying the particulars and documents submitted by the applicant, shall undertake an assessment in order to determine whether the feed additive complies with the conditions laid down in Article 5. EFSA shall deliver an opinion on the safety for the target animals, consumer, user and the environment and on the efficacy of the feed additive consisting of chromium chelate of dl‐methionine (Availa® Cr) when used under the proposed conditions of use (see Section 3).

Additional information

1.2

Chromium chelate of dl‐methionine is currently authorised for use in feed for salmonids (4d30).3

The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) adopted several opinions on the safety/efficacy of this product (EFSA, 2009; EFSA FEEDAP Panel, 2020, 2023, 2025).

DATA AND METHODOLOGIES

2

Data

2.1

The present assessment is based on data submitted by the applicant in the form of a technical dossier4 in support of the authorisation request for the use of chromium chelate of dl‐methionine (Availa® Cr) as a feed additive.

The confidential version of the technical dossier was subject to a target consultation of the interested Member States from 10 January 2025 to 10 April 2025; the comments received were considered for the assessment.

In accordance with Article 38 of the Regulation (EC) No 178/20025 and taking into account the protection of confidential information and of personal data in accordance with Articles 39 and 39e of the same Regulation, and of the Decision of EFSA's Executive Director laying down practical arrangements concerning transparency and confidentiality,6 a non‐confidential version of the dossier has been published on Open.EFSA.

According to Article 32c(2) of Regulation (EC) No 178/2002 and to the Decision of EFSA's Executive Director laying down the practical arrangements on the pre‐submission phase and public consultations, EFSA carried out a public consultation on the non‐confidential version of the technical dossier from 28 March to 18 April 2025, for which no comments were received.

The FEEDAP Panel used the data provided by the applicant together with data from other sources, such as previous risk assessments by EFSA or other expert bodies, peer‐reviewed scientific papers, other scientific reports and experts' knowledge, to deliver the present output.

The European Union Reference Laboratory (EURL) considered that the conclusions and recommendations reached in the previous assessment regarding the methods used for the control of the active substance in animal feed are valid and applicable for the current application.7

Methodologies

2.2

The approach followed by the FEEDAP Panel to assess the safety and efficacy of chromium chelate of dl‐methionine (Availa® Cr) is in line with the principles laid down in Regulation (EC) No 429/20088 and the relevant guidance documents: Guidance on the assessment of the safety of feed additives for the consumer (EFSA FEEDAP Panel, 2017a), Guidance on the assessment of the safety of feed additives for the target species (EFSA FEEDAP Panel, 2017b), Guidance on the assessment of the safety of feed additives for the environment (EFSA FEEDAP Panel, 2019), Guidance on the assessment of the safety of feed additives for the users (EFSA FEEDAP Panel, 2023), Guidance on the assessment of the efficacy of feed additives (EFSA FEEDAP Panel, 2024).

ASSESSMENT

3

Chromium chelate of dl‐methionine (Availa® Cr) is intended to be used as a zootechnical additive (functional group: other zootechnical additives) in feed for all finfish to improve their growth performance. The additive is specified to contain chromium chelate of dl‐methionine ■■■■■ (minimum of 1000 mg Cr/kg of additive), vegetable oil ■■■■■, calcium carbonate ■■■■■ and ■■■■■ Zinpro® F‐Yellow #5 Lake ■■■■■.9

EFSA has assessed the additive in the context of previous applications for the use of the additive in dairy cows and salmonids. The additive has been characterised, and the safety and efficacy have been evaluated in previous assessments. In the last opinion (EFSA FEEDAP Panel, 2025), the FEEDAP Panel concluded that the additive is safe for salmonids at the maximum recommended use level of 600 mg additive/kg complete feed (corresponding to 0.6 mg Cr/kg complete feed). The use of the additive in animal feed was considered safe for consumers and the environment.

Regarding user safety, the additive was considered not to be an eye nor skin irritant, but due to the presence of nickel, the additive was considered a skin and respiratory sensitiser. Inhalation and dermal exposure were considered a risk. The FEEDAP Panel concluded that the additive may have the potential to be efficacious in improving the performance of salmonids at the proposed minimum use level of 200 mg additive/kg complete feed (0.2 mg Cr/kg complete feed).

The ■■■■■ Zinpro® F‐Yellow #5 Lake was also previously characterised and its safety assessed (EFSA FEEDAP Panel, 2025).

In the context of the current application, the additive is intended for use in feed for all finfish, at a proposed minimum content of 200 mg additive/kg complete feed (corresponding to 0.2 mg Cr/kg complete feed) and a maximum content of 600 mg additive/kg complete feed (corresponding to 0.6 mg Cr/kg complete feed).

No new information regarding the identity and the characterisation of the additive has been submitted. The FEEDAP Panel considers that the information evaluated in the previous opinion (EFSA FEEDAP Panel, 2025) also applies to the use of the additive in feed for all finfish.

Safety

3.1

The applicant did not provide any new information regarding the safety for the user and the environment. The FEEDAP Panel considers that the use of the additive in feed for all finfish would not add any additional risks for the user and the environment compared to those already assessed in the previous assessment for the use of the additive in salmonids (EFSA FEEDAP Panel, 2025). Therefore, the Panel reiterates its previous conclusions that the use of the additive in animal feed is safe for the environment, and that the additive is neither an eye nor skin irritant, but due to the presence of nickel, the additive is considered a skin and respiratory sensitiser. Inhalation and dermal exposure are considered a risk.

Safety for the target species

3.1.1

In a previous opinion (EFSA FEEDAP Panel, 2025), a combined tolerance/efficacy study on rainbow trout (Oncorhynchus mykiss) was assessed, and the additive Availa® Cr was considered safe for salmonids at the maximum proposed use level of 600 mg additive/kg complete feed (corresponding to 0.6 mg Cr/kg complete feed).

In the current application, a tolerance trial assessing the effects of the additive up to 6000 mg/kg complete feed (corresponding to 10× the maximum proposed use level) on the performance, blood haematology and biochemistry and organs gross pathology in Nile tilapia (Oreochromis niloticus) was provided.10 However, due to inappropriate sampling methodology, the quality of the methods of analysis used (high limit of quantification for several parameters) and the lack of justification regarding the results of analysis out of the analytical range, a relevant number of required blood parameters could not be adequately evaluated. Consequently, the results of the haematology and biochemistry analyses could not be used for the assessment of the safety of the additive. Therefore, the study was not further considered as evidence for the safety of the additive for the target species.

Conclusions on safety for the target species

3.1.1.1

Based on the results of the tolerance study in rainbow trout previously assessed, the FEEDAP Panel concluded that the use of Availa® Cr up to 600 mg/kg complete feed is safe for salmonids. In the absence of an adequate study in another fish species, the Panel is not in the position to conclude on the safety of the use of Availa® Cr in feed for other finfish.

Safety for the consumer

3.1.2

In the context of the tolerance study in Nile tilapia, chromium was measured in flesh at the end of the study (90 days). The results showed no differences in deposition among the three analysed treatments (control group, 0.6 mg Cr/kg complete feed and 6 mg Cr/kg complete feed). The analysed values (55–76 μg Cr/kg tissue)11 were in the same range of the ones measured in flesh from rainbow trout (70–80 μg Cr/kg tissue) subject of the previous assessment of the additive for salmonids (EFSA FEEDAP Panel, 2025). Therefore, the FEEDAP Panel concludes that the use of the additive in all finfish at the maximum proposed use level of 600 mg additive/kg complete feed (corresponding to 0.6 mg Cr/kg complete feed) is safe for the consumer.

Efficacy

3.2

Two efficacy studies performed on rainbow trout (Oncorhynchus mykiss) and one in Atlantic salmon (Salmo salar) were assessed under the previous application (EFSA FEEDAP Panel, 2025). The additive was considered to have the potential to be efficacious in improving the performance of salmonids at the minimum content of 200 mg additive/kg complete feed (corresponding to 0.2 mg Cr/kg complete feed).

In the current application, one trial in gilthead seabream (Sparus aurata)12 and one trial in African catfish (Clarias gariepinus) were provided.13 A summary of the experimental design of both trials is described in Table 1.

In both studies, fish were distributed in 16 tanks, which were randomly allocated to four experimental groups. The basal diets were either not supplemented (control) or supplemented with Availa® Cr at 200, 400 or 600 mg/kg to provide 0.2 (minimum proposed use level), 0.4 and 0.6 mg Cr/kg complete feed. The analysis of the total Cr of the diets confirmed the inclusion rates in the seabream trial. However, in the catfish trial, the analysed values showed inclusion rates much higher (180%–250%) than the intended ones (see Table 1). The experimental feeds were offered as extruded pellets for a minimum of 84 days. In the case of seabream, the feed was offered to visual satiety; for catfish, the feed was offered to visual satiety during the day and at a fixed rate of 0.5% BW during the night.

Fish health and mortality were monitored daily, and the most likely cause of death was recorded. Tank body weight was measured at the start and end of the trial, and feed intake was recorded daily. The relative daily feed intake, specific growth rate and feed to gain ratio were calculated.

The experimental data were analysed with a one‐way analysis of variance (ANOVA), with the tank as the experimental unit and the diet as a fixed effect. When differences were observed, group means were compared with a Student–Newman–Keuls test (seabream) or Tukey test (catfish). The statistical significance level was set at 0.05. The main effects of the additive on the performance parameters are shown in Table 2.

In the seabream trial, fish supplemented with the additive at any level showed higher final body weight and specific growth rate, and better feed‐to‐gain ratio than the control group. In the catfish trial, the groups supplemented with the additive showed higher final body weight and specific growth rate than the control, although these values were not significantly different in the group supplemented with the highest content of Cr. The Panel notes that the minimum analysed level applied in the catfish trial was 0.51 mg Cr/kg complete feed.

The applicant provided three trials in salmonids (EFSA FEEDAP Panel, 2025) and two in other finfish species (seabream and catfish) showing improved productive performance of the fish supplemented with the additive. Therefore, the Panel concludes that Availa® Cr has the potential to be efficacious when supplemented in the diet of all finfish. The minimum efficacious level is considered to be 0.2 mg Cr/kg complete feed for salmonids and 0.5 mg/kg complete feed for other finfish.

Conclusions on efficacy

3.2.1

The additive has the potential to be efficacious in salmonids at 0.2 mg Cr/kg complete feed and in other finfish at 0.5 mg Cr/kg complete feed.

Post‐market monitoring

3.3

The FEEDAP Panel considers that there is no need for specific requirements for a post‐market monitoring plan other than those established in the Feed Hygiene Regulation14 and good manufacturing practice.

CONCLUSIONS

4

The FEEDAP Panel concludes that the additive Availa® Cr is safe for salmonids at the maximum proposed use level of 600 mg additive/kg complete feed (corresponding to 0.6 mg Cr/kg complete feed). The FEEDAP Panel is not in the position to conclude on the safety of the use of Availa® Cr in feed for other finfish.

The use of the additive in finfish feed at the maximum proposed use level is considered safe for the consumer and for the environment.

Regarding user safety, the FEEDAP Panel concludes that the additive is neither an eye nor skin irritant, but due to the presence of nickel, the additive is considered a skin and respiratory sensitiser. Inhalation and dermal exposure are considered a risk.

The additive has the potential to be efficacious in salmonids at 0.2 mg Cr/kg complete feed, and in other finfish at 0.5 mg Cr/kg complete feed.

ABBREVIATIONSANOVAanalysis of varianceBWbody weightEURLEuropean Union Reference LaboratoryFEEDAPEFSA Scientific Panel on Additives and Products or Substances used in Animal Feed

REQUESTOR

European Commission

QUESTION NUMBER

EFSA‐Q‐2024‐00533

COPYRIGHT FOR NON‐EFSA CONTENT

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PANEL MEMBERS

Roberto Edoardo Villa, Giovanna Azimonti, Eleftherios Bonos, Henrik Christensen, Mojca Durjava, Birgit Dusemund, Ronette Gehring, Boet Glandorf, Maryline Kouba, Marta López‐Alonso, Francesca Marcon, Carlo Nebbia, Alena Pechová, Miguel Prieto‐Maradona, Ilen Röhe, and Katerina Theodoridou.

LEGAL NOTICE

Relevant information or parts of this scientific output have been blackened in accordance with the confidentiality requests formulated by the applicant pending a decision thereon by EFSA. The full output has been shared with the European Commission, EU Member States (if applicable) and the applicant. The blackening may be subject to review once the decision on the confidentiality requests is adopted by EFSA and in case it rejects some of the confidentiality requests.