Guanidinoacetic acid also in drinking water for pigs and turkeys: 200–600 mg/L determined by ion chromatography with UV detection, cyanamide ≤ 0.03 %, and the amount in water may not exceed the equivalent of 1200 mg/kg feed
Commission Implementing Regulation (EU) 2025/2505, published on 12 December 2025, authorises until 1 January 2036 guanidinoacetic acid (GAA, Alzchem Trostberg GmbH) in drinking water for weaned piglets and pigs for fattening (200–600 mg/L) and in feed (600–1200 mg/kg) and water (300–600 mg/L) for turkeys for fattening and reared for breeding. The applicant wanted the additive for pigs classified as an amino acid; the Commission — following EFSA — authorised it, as before, in the group “other zootechnical additives”.
- Method in the annex for the additive, premixtures, compound feed and drinking water: ion chromatography with UV detection (IC-UV). Additive: GAA at least 98 % on dry matter (preparation — at least 96 %), cyanamide up to 0.03 %, dicyandiamide up to 0.5 %; the label must state the moisture content and the directions for use the stability in drinking water.
- Because animals drink 2–3 times more water than they eat feed (on dry matter), the amount of GAA in water may not exceed what the animal would receive with feed at 1200 mg/kg; for pigs it may also not be lower than at 600 mg/kg. The additive may not be given simultaneously in feed and water. The same condition was added to the authorisation for chickens (Regulation (EU) 2023/2628).
- In the tolerance study described in the EFSA opinion (640 B.U.T. 6 turkeys, 42 days, doses of 1200, 2400 and 6000 mg/kg) the GAA content of the feed was confirmed by analysis, and GAA, creatine, creatinine, homocysteine and α1-acid glycoprotein were determined in serum. GAA (6.8–71.8 µmol/L), creatine and creatinine concentrations rose with the dose; EFSA did not consider this an adverse effect.
- EFSA considered GAA safe for turkeys at 1200 mg/kg feed or 600 mg/L water, assuming the feed contains enough methyl donors other than methionine (choline, betaine, folic acid) and vitamin B12 — the regulation requires attention to this when the additive is used. According to EFSA GAA is not an amino acid, because it is converted only into creatine.