What Is Rumen-Protected L-Lysine Monohydrochloride 50% (RPL) - Palm-Fat Coated Granules? Applications, Dosage, Alternatives & Specifications
Last updated: 2026-11-14 · CAS 657-27-2 · Feed Grade
- Quick facts
- Name
- Rumen-Protected L-Lysine Monohydrochloride 50% (RPL) - Palm-Fat Coated Granules
- CAS number
- 657-27-2
- Grade
- Feed Grade
- Certifications
- ISO 9001 · ISO 22000 · HACCP · FAMI-QS · Kosher · Halal · GMP · SGS
- Application areas
- 3
- Documentation
- COA · TDS · SDS
Overview
Rumen-Protected Lysine (RPL) is a feed additive produced by physically protecting L-lysine hydrochloride through a palm-oil (vegetable fat) coating to maintain stability in the rumen of ruminants (rumen degradation rate below 15%) and to release and be absorbed in the abomasum and small intestine. Lysine is the second limiting amino acid for ruminants, especially dairy cows (methionine being the first limiting amino acid). However, ordinary lysine added directly to feed is rapidly degraded by rumen microorganisms (degradation rate exceeding 80%) and cannot reach the small intestine to exert its nutritional effects. Rumen-protected technology is the key to solving this bottleneck. Rumen-protected lysine is released in the small intestine after passing through the rumen, increasing the amount of lysine entering the small intestine, improving small intestinal amino acid balance, and enhancing dairy cow production performance, feed utilization efficiency, and nitrogen utilization efficiency. Rumen-protected lysine is listed in China's "Catalog of Feed Additives." The product is manufactured and tested under the manufacturer enterprise standard Q/371626FLK 017-2026.
Rumen-protected lysine can be divided into the following main varieties by coating material, production process, and content specification.
Applications
Dairy Cattle
The core market for rumen-protected lysine; RPL raises digestible lysine to support milk protein and casein yield and the ideal lysine-to-methionine ratio.
Beef Cattle
Supplies metabolizable lysine for lean tissue and skeletal development, improving growth and protein efficiency without excess crude protein.
Sheep & Ruminants
Coated lysine helps balance limiting amino acids across small ruminant rations, supporting growth and reducing nitrogen excretion.
Specification
| Item | Specification | Test Method / Note |
|---|---|---|
| Appearance | Yellowish to light brown granules, good fluidity | Visual (COA batch 20260603A: Conform) |
| L-Lysine Hydrochloride Content | ≥50% (batch result 50.06%) | HPLC |
| Carrier / Coating | Palm oil (vegetable fat); fat <50% | — |
| Rumen Bypass Rate | ≥85% (batch: Conform) | Nylon-bag / in vitro simulation |
| Intestinal Release Rate | ≥90% (batch: Conform) | Intestinal fluid digestion |
| Loss on Drying | ≤5% (batch result 0.90%) | Drying, 105 °C |
| Particle Size | 100% through 10 mesh (2.00 mm) | Sieving |
| Molecular Formula / Weight | C6H14N2O2·HCl · MW 182.65 | TDS |
| Test Method Standard | Q/371626FLK 017-2026 | Manufacturer enterprise standard |
| Packaging | 25 kg / bag | — |
| Shelf Life | 12 months, sealed, cool & dry | TDS |
Packaging & Storage
- Packing: 25 kg net kraft/PP woven bags with PE liner; fibre drum available on request.
- Sample: 100-500g free sample available.
- Storage: Keep in tightly closed packaging, cool, dry, well-ventilated. Protect from light and moisture.
- Shelf Life: 12 months from production date.
Quality & Certifications
Every batch tested by in-house QC lab. COA, TDS, SDS provided with each shipment.
Regulatory & Compliance
EU
Complies with EU regulations and FAMI-QS standards.
USA
Meets FDA and AAFCO requirements.
China
Registered under Chinese MOA regulations.
International
Kosher, Halal, ISO certified. FTA forms available.
Safety & Handling
- Hazard Class: Generally non-hazardous. Refer to SDS for details.
- Storage: Room temperature, dry, sealed. Avoid strong oxidizers.
- Transport: Non-dangerous goods. Standard sea/air freight.
- SDS: Available on request at sales@xadditive.cn.
Frequently asked questions
What is rumen-protected lysine (RPL)?
Rumen-protected lysine is a feed additive in which L-lysine hydrochloride granules are coated with a solid palm-fat layer so the amino acid survives the rumen and is released and absorbed in the abomasum and small intestine. It contains ≥50% L-lysine HCl and has CAS number 657-27-2.
How does coated lysine bypass the rumen?
The palm-fat coating remains solid and resists rumen microbial degradation as the granule passes through the rumen. In the abomasum and small intestine the coating breaks down, releasing the lysine for absorption into the bloodstream.
What is the rumen bypass rate of protected lysine?
The ZEAL palm-fat coated RPL has a rumen bypass rate of ≥85% and an intestinal release (digestion and absorption) rate of ≥90%, measured by nylon-bag/in-vitro and intestinal-fluid methods.
How much rumen-protected lysine should dairy cows receive?
The reported optimal level for dairy cows is about 30 g per head per day; up to 40 g/head/day in late lactation can raise milk fat and total solids. Rations are normally formulated to a target percentage of digestible lysine in metabolizable protein.
Why balance the lysine-to-methionine (Lys:Met) ratio?
Lysine and methionine are the two most limiting amino acids for milk protein. Feeding RPL together with rumen-protected methionine lets nutritionists hit the ideal Lys:Met ratio without adding excess crude protein, improving protein efficiency and reducing nitrogen excretion.
What is the difference between coated lysine and ordinary lysine?
Unprotected lysine is largely broken down by rumen microbes before it can be absorbed. Coated lysine bypasses the rumen (≥85%) and is released at ≥90% in the small intestine, so a much greater fraction reaches the cow as metabolizable lysine.
Does RPL improve milk protein and nitrogen efficiency?
Yes. Peer-reviewed trials report higher milk protein and casein yield, energy-corrected milk and improved nitrogen utilization, with reduced urea and nitrogen excretion when RPL is added.
Is lysine the first or second limiting amino acid?
For dairy cows lysine is generally the second limiting amino acid, after methionine. Requirements for both rise together, which is why protected lysine and protected methionine are commonly used in combination.
What is the shelf life and packaging of coated lysine?
It is packed in 25 kg bags with a PE liner and has a 12-month shelf life when stored sealed in a cool, dry, well-ventilated place away from light and moisture.
What is the MOQ and can I get a free sample?
The trial MOQ is 1 kg and 25 kg for regular orders. Free samples are available; contact sales@xadditive.cn and a quotation is usually provided within 30 minutes.
Request a quote & COA
Ask for the current specification sheet, a COA sample and a bulk quotation — reply within 30 minutes on working days.