Amino Acid Profile

要点

The amino-acid profile — and above all digestible lysine, methionine, threonine and tryptophan — is what protein ingredients are actually bought for in modern formulation.

測定単位・方法: g/100 g by ion-exchange chromatography or UPLC after hydrolysis; SID coefficients applied per species

Total versus standardised ileal digestible

Total amino acids are what the laboratory finds; standardised ileal digestible (SID) amino acids are what the animal absorbs. Two cargoes with identical total lysine can differ materially in SID lysine after over-toasting, and only the SID value predicts performance.

Heat damage indicators

Reactive (available) lysine, KOH protein solubility, protein dispersibility index and urease activity are practical proxies for processing intensity. Specifying at least one of them protects against under- and over-processing, which crude protein cannot detect.

一般的な参考値

Soybean meal lysine	2.7–2.9%	Reference plant protein
Fish meal lysine	4.5–5.2%
Rapeseed meal lysine	1.8–2.1%
SID lysine (poultry, SBM)	≈ 89–91%	Falls with heat damage

Indicative industry reference values for orientation only — always contract against the delivered lot.

確認すべき事項

—Digestible, not only total, amino-acid values with the species basis stated
—A heat-damage proxy appropriate to the ingredient
—Consistency of the amino-acid to crude-protein ratio across shipments

主なリスク

—Silent loss of digestible lysine through over-processing
—Under-processing leaving anti-nutritional factors active
—Formulation shortfalls that only appear as performance loss weeks later

よくある誤り

—Buying protein meals on crude protein alone
—Applying one origin's SID coefficients to a different process route

よくある質問

Which amino acid should be specified first?

Lysine for most monogastric protein sources, because it is usually first limiting and the most sensitive to heat damage. Methionine, threonine and tryptophan follow depending on species and diet stage.

特に重要な原料

Soybean Meal Fish Meal L-Lysine Methionine