What is L-lysine sulphate?
L-lysine sulphate is produced by bacterial fermentation, like other feed-grade lysine. The difference is in the downstream process: instead of isolating and crystallising lysine as the hydrochloride, the broth is neutralised with sulphuric acid and the whole mass, including much of the fermentation solids, is concentrated and granulated. For the role of lysine in animal nutrition, see our general page on lysine.
The result is a free-flowing, usually brownish granulate with a lower lysine concentration than lysine HCl but fewer purification steps.
Composition: what "70%" and "55%" mean
Lysine sulphate is commonly traded as "70%". This figure describes the product grade as declared by the producer; it is not the lysine content. The value that matters for formulation is the guaranteed L-lysine content, which for most products is around 55%. In the EU, authorisations for several lysine sulphate products describe a granulate with a minimum of 55% L-lysine; local regulations and the product label prevail.
The rest of the product consists of sulphate and of other fermentation components such as residual biomass, carbohydrates and small amounts of other amino acids. These contribute some energy, crude protein and sulphur to the diet, and some nutritionists assign them a matrix value, based on supplier data.
Typical specification items
- Guaranteed L-lysine content (e.g. at least 55%), as is.
- Moisture: low, as stated in the specification; important for granule stability.
- Sulphate content, relevant for the sulphur and electrolyte balance.
- Particle size distribution and bulk density of the granules.
- Heavy metals and microbiological quality within supplier and regulatory limits.
- Certificate of analysis (CoA) and lot number on every delivery; lysine content can vary between lots more than with crystalline lysine HCl.
Handling and storage
The granulated form generally flows well and creates little dust, which suits automated dosing. Like other fermentation products it can take up moisture, so bags should be kept closed in a cool, dry place, off the floor, and used on a first-in, first-out basis. Because the granules are larger and lighter than lysine HCl crystals, the dosing system should be checked for accuracy when switching products.
Conversion and comparison with lysine HCl
Conversion is always done on an L-lysine basis. Example: replacing 1 kg of lysine HCl (about 78.8% L-lysine, i.e. 0.788 kg lysine) with a lysine sulphate product guaranteed at 55% L-lysine requires about 0.788 ÷ 0.55 ≈ 1.43 kg. The extra mass takes space in the formula and brings its own sulphate and fermentation solids, which should be reflected in the matrix.
- Lysine HCl: higher lysine concentration, crystalline, adds chloride.
- Lysine sulphate: lower lysine concentration, granular, adds sulphate instead of chloride plus some energy and other nutrients.
- Bioavailability: L-lysine from both forms is used by the animal; the practical comparison is the price per kg of L-lysine delivered and the effect on the rest of the formula.
CTF Premix and L-lysine sulphate
L-lysine sulphate can be included in CTF Premix's vitamin, mineral and custom premixes according to the customer's formulation, calculated on an L-lysine basis together with other amino acids, vitamins and trace minerals. Our premixes are produced at our Ankara facility under ISO 9001:2015 and GMP, and every lot has a certificate of analysis and full lot traceability.
This page is for general information. Inclusion rates and product choice should be decided with a nutritionist, taking into account the species, the feed formulation and the applicable regulations.