DL-methionine protected with copolymer vinylpyridine/styrene

What it is. This additive is synthetic DL-methionine, an essential sulfur amino acid, coated with a vinylpyridine/styrene copolymer. The coating is designed to modulate the amino acid's release along the digestive tract.

What it is for. It is used to supply methionine, a first limiting amino acid in many diets, as part of ration formulation on a digestible amino acid basis. Protective coating is intended to limit ruminal degradation, so this form is mainly of interest for ruminants, allowing part of the methionine to reach the intestine. It can also be considered in monogastric diets where a protected amino acid source is sought, according to formulation objectives.

Points to watch. Authorisation is granted for all animal species; actual use should follow the accepted conditions of use and any purity criteria set for the additive. Supplementation must be balanced against other amino acid sources and total sulfur amino acid supply in the diet to avoid imbalance. Protected forms may show variability in rumen bypass rate depending on manufacturing process; store under dry conditions away from heat to preserve coating integrity.