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Ronozyme® RumiStar™ contains alpha-amylase. The product is authorized for use in the EU only in dairy cows. Ronozyme® RumiStar™ is available both as a dry application (CT) (Powder) or as a liquid application (L) (Liquid). RONOZYME® RumiStar™ is an innovative development in dairy cow nutrition which helps farmers achieve increased feed efficiency. Getting more milk from a given amount of feed is the goal of all dairy farmers, as feed is the greatest cost factor. So any increase in milk efficiency translates into an increase in their returns.
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Identification & Functionality

EU Category

Zoo-technical Additives

Functional Group of Additives

Digestibility Enhancer

Active Substance

Alpha-amylase (EC

Features & Benefits

  • Powder: sodium sulphate, calcium carbonate or kaolin, dextrin and sucrose, sodium chloride, hydrogenated palm oil, cellulose and sodium thiosulphate
  • Liquid: sucrose, sodium chloride, methionine, water

Applications & Uses

How Its Works

A pure amylase, it releases more of the starch energy in corn-based rations. This provides more starch energy to the animal and also increases forage digestion. As a result, cows make better use of their total diet and can allow increased forage use, which reduces feed costs.

Where cows are fed RONOZYME® RumiStar™, the response has been an extra 1.5kg more milk with no increase in feed intakes – a significant rise in milk efficiency and financial returns indeed.

EU Approval, Minimum Content

Dairy cows: 300 KNU/kg complete feed


The distribution of the additive when added to either a premix or a complete feed was tested. Six sub-samples from three batches of premixtures and complete feed. The subsequent analyses showed a coefficient of variance in the premixtures of 5.1% and 2.8% in the complete feed. Complete feed supplemented with the liquid product showed a coefficient of variance of 3.4%

Regulatory & Compliance

End of Period of EU Authorisation

4 February 2025

EU Code


Technical Details & Test Data

Activity in the Product
  • Solid form: 160 KNU/g
  • Liquid form: 240 KNU/g

Storage & Handling

Storage Stability

Storage of the product (both dry and liquid) for 12 months at temperatures up to 25°C did not reduce enzymatic activity. When stored at 40°C the residual enzymatic activity was higher than 70%

Storage stability in feed

In premixtures supplemented with the product and stored for 3 or 6 months, the recovered activities were greater than 80% and 74%, respectively

Heat stability

The heat stability of the enzyme was tested at two different temperatures: 75°C and 85°C. At 75°C 76% of the activity could be recovered and at 85°C the rate of recovery was 90%


Breathing protection, protection glasses and gloves shall be used during handling

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