Copper(II)-betaine complex authorised in feed for all animals: formation of the complex confirmed by XRD, betaine by HPLC-RI, and nickel limited to 77 mg/kg after batches with 67.6–76.8 mg/kg
Commission Implementing Regulation (EU) 2025/2513, published on 12 December 2025, authorises until 1 January 2036 the copper(II)-betaine complex as a source of copper for all animal species — within the existing maximum copper contents, from 15 mg/kg for sheep to 150 mg/kg for piglets up to 4 weeks after weaning. Only the third EFSA opinion confirmed the efficacy of the additive.
- Specification: copper at least 19 %, betaine at least 36 %, sulfur 9–12 %, moisture up to 5 %, nickel up to 77 mg/kg. The applicant proposed 100 mg/kg nickel; in the first EFSA opinion three batches had 10.5–15.8 mg/kg, and three further batches in the new submission — 67.6, 73.4 and 76.8 mg/kg, which EFSA attributed to the large variation of nickel in the raw materials.
- Methods in the annex: copper in the additive, premixtures and feed — ICP-AES according to EN 15621 or EN 15510, AAS according to ISO 6869 or Annex IV-C to Regulation (EC) No 152/2009, in premixtures and feed also ICP-MS according to EN 17053; betaine — HPLC with refractive index detection; sulfur and sulfate — ICP-AES (EN 15621); formation of the complex — X-ray powder diffraction (XRD).
- In the first two opinions (2023) EFSA could not confirm efficacy because copper deposition in chicken tissues showed no consistent dose–response. In a new 35-day study with 560 Ross 308 chickens the complex group at one of the tested doses had significantly more copper in liver and skin with fat than the control, so in its opinion of 6 May 2025 EFSA considered the additive a bioavailable source of copper for all species.
- The label of feed for sheep with more than 10 mg/kg copper warns of poisoning in certain breeds, and for cattle after the start of rumination with less than 20 mg/kg — of copper deficiency on pastures rich in molybdenum or sulfur. EFSA considered the additive irritant to the eyes and, because of nickel, a skin and respiratory sensitiser.