Histidine

L-Histidine · His · Carnosine precursor

Mechanism

Histidine is an essential amino acid and the direct precursor of the dipeptide carnosine (beta-alanyl-L-histidine), which occurs in high concentration above all in the fast-contracting type II muscle fibres of the horse, where it acts as an intracellular pH buffer as well as an antioxidant and metal chelator. Equine muscle analyses show very high carnosine contents, particularly in glycolytic fibres. Carnosine synthesis, however, is limited predominantly by the availability of beta-alanine and not of histidine, so that pure histidine supply raises muscle carnosine content only to a limited degree. Histidine/carnosine has been associated with the field of muscular acid buffering during intense, anaerobic exertion. Much of the mechanistic rationale comes from human sports physiology; controlled equine performance data are limited. A specific histidine requirement is not separately quantified in NRC 2007 and GfE 2014.

Cautions

· Muscle carnosine is limited primarily by beta-alanine - histidine alone barely raises carnosine content.
· Usually already covered via normal ration protein; isolated supplementation rarely necessary.
· Equine performance data limited; transfer predominantly from human sports physiology.

Sources

Dunnett & Harris 1999Dunnett M, Harris RC 1999 (Equine Vet J Suppl) - orale beta-Alanin/L-Histidin-Gabe und Muskelcarnosin im M. gluteus medius

Sewell et al. 1992Sewell DA, Harris RC et al. 1992 - Carnosingehalt der equinen Muskelfasertypen (M. gluteus medius)

NRC 2007NRC - Nutrient Requirements of Horses (2007): Aminosäuren, kein separater Histidin-Bedarf

Equiterna Score

58/100

solid

Science4.5/10

Practical experience6/10

Safety7.2/10

Overall score scale

high overall75–100solid55–74limited0–54

How the Equiterna Score is built

The Equiterna Score combines three dimensions into a value of 0-100: science (40%), practical experience (30%) and safety (30%). It is transparently derived from evidence level, attributed sources (PubMed/journals), legal classification and cautions. The FEI doping status is shown separately as a competition-law note and does not enter the score. Commissions and vendor relationships have no influence on the score. In addition, the editorial safety rating caps the result: it limits the safety dimension and the overall tier (orange: at most solid). For entries rated red, no score is calculated at all. The rating never raises anything — a green rating does not lift a calculated value.

An editorial assessment of the evidence and safety situation — not a healing claim and not an individual recommendation. It does not replace veterinary advice.

DosageNo separately quantified requirement (NRC 2007 / GfE 2014); usually covered via ration protein. For a carnosine-oriented strategy, beta-alanine is more likely the limiting factor; robust histidine guideline values for the horse are not established.

AMG statusComplementary feed

FEI statusNot listed

SafetyVery safe

Evidenceemerging

Usage note

This content is for information and education. It does not replace veterinary diagnosis or treatment. If your horse shows signs of illness, consult a veterinarian.

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Equiterna is an intermediary platform for equine knowledge, marketplace and tools — not a veterinary-medicines dealer, veterinary practice or pharmacy. Compound information is study-attributed and free of healing claims. Legal framework: Regulation (EU) 2019/6 / TAMG (DE/AT), Feed Regulation (EC) 767/2009, FEI Prohibited Substances List, HWG.