What is threonine?
Threonine is one of the 20 protein-forming amino acids. Its side chain carries a hydroxyl group, and it has two chiral centres; L-threonine is the biologically active form used in feed. Animals cannot synthesise threonine, so it is an essential amino acid.
Cereals and many by-products such as wheat bran and distillers' grains supply relatively little digestible threonine. As synthetic lysine and methionine are used to lower crude protein, threonine soon becomes the next amino acid to limit performance.
What does it do in animal feed?
- Protein synthesis: needed for muscle growth, daily gain and feed conversion in pigs and poultry.
- Gut health: threonine is a major component of mucins, the glycoproteins that form the protective mucus layer of the intestine. A large part of dietary threonine is used by the gut itself.
- Immune function: immunoglobulins are rich in threonine, so demand can rise when animals face health challenges.
- Feathering: threonine is also part of feather protein in poultry.
- Sows and layers: contributes to milk protein and egg production.
Forms and sources
Feed-grade threonine is L-threonine produced by bacterial fermentation, then purified and crystallised. It is supplied as a free-flowing powder or small crystals, typically with a purity of at least 98.5%. Some rumen-protected amino acid products for ruminants also exist, but threonine is mainly used in monogastric diets.
Natural sources of threonine in feed include soybean meal, other oilseed meals and animal proteins; cereals provide smaller amounts.
How is the threonine requirement set?
Threonine is usually formulated on a digestible basis as a ratio to digestible lysine (the ideal protein concept). The ratio and absolute requirement depend on species, age, production stage and health status. Diets with more fibre or more challenging conditions can increase the threonine used by the gut, which nutritionists take into account when setting the ratio.
Synthetic L-threonine covers the shortfall left by the raw materials, allowing reduced-protein diets while keeping amino acid balance.
Quality criteria
- Purity / L-threonine content (typically at least 98.5%).
- Moisture, ash, heavy metals and microbiological quality.
- Particle size and flowability for even distribution in premixes and feed.
- Certificate of analysis (CoA) and lot traceability.
CTF Premix and threonine
Threonine can be included in CTF Premix's vitamin, mineral and custom premixes according to the customer's formulation, alongside other amino acids, vitamins and trace minerals. Our premixes are produced at our Ankara facility under ISO 9001:2015 and GMP, and every lot is traceable and supplied with a certificate of analysis.
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.