L-Cysteine - Feed Ingredient

L-Cysteine is a sulfur-containing, non-essential amino acid that plays a role in protein synthesis, antioxidant defense, and various metabolic processes. It can be synthesized by the horse from methionine but may be conditionally essential in situations of increased demand, such as stress, illness, or intensive exercise.

In equine nutrition, L-cysteine is sometimes included in specialty supplements, particularly those targeting coat condition, hoof health, or antioxidant support. It is a precursor to glutathione, one of the body’s key endogenous antioxidants, and contributes to the structure of keratin, the protein that makes up hair and hooves.