23. June 2022

Test shows: FreshFoss is more effective at reducing heat generation in complete feed than pure potassium sorbate

In recent years, a number of tests have been conducted on agents intended for reducing heat generation in TMR compounds. Previous product comparisons have found that FreshFoss is the strongest product on the market (Kristensen, 2018, 2019). Since then, however, the use of pure potassium sorbate has become widespread. The purpose of this test was therefore to investigate the strength of these two products in relation to reducing heat generation.

Vilofoss has therefore performed three tests on three different days, where both potassium sorbate and FreshFoss have been tested at comparable dosages. The complete feed, used in the tests, is collected from the same farmer immediately after feeding. The complete feed is added to either potassium sorbate or FreshFoss and stirred thoroughly in a bucket, after which the temperature development is logged every half hour for each treatment.

Test 1

FreshFoss test  

Test 1. Temperature development in TMR by adding 0.4 kg / t FreshFoss or potassium sorbate.

It is viewed in test 1 that the two treatments with 0.4 kg FreshFoss /t TMR keep the heat generation down for a longer period than the two treatments with 0.4 kg potassium sorbate/t TMR. This shows that FreshFoss is more effective at inhibiting yeast and fungal growth.

Test 2

Test 2. Temperature development in TMR by addition of FreshFoss or potassium sorbate compared to control.

In this test, 0.4 kg of potassium sorbate / t TMR was roughly at the same efficiency as 0.4 kg of FreshFoss /t TMR in terms of reducing heat generation.

Test 3

Test 3. Heat generation in TMR at different dosages of FreshFoss and potassium sorbate

It is viewed that complete feed added 0.3, 0.4 or 0.5 kg FreshFoss per tonnes of complete feed had a better stability than 0.4 kg of potassium sorbate /t complete feed. This test indicates a better efficiency of FreshFoss compared to potassium sorbate in controlling the aerobic stability.

Another way to represent aerobic stability is to measure the time to a given temperature rise in the complete feed, e.g. 5 degrees Celsius. The higher the number of hours - the more efficient the product. This is summarized in the table.

  Test 1   Test 2  Test 3  Average
Potassium sorbate, 0.4 kg/t  100  100  100  100
 FreshFoss 0.4 kg/t  113  98  110  106

Table 1. The aerobic stability of potassium sorbate and FreshFoss compared at the same supplementation rate. Potassium sorbate is 100% and the effectiveness of FreshFoss is relative to this.

On average, the aerobic stability of FreshFoss was 6% better than potassium sorbate.


The difference in the efficiency of the products in relation to the reduction of heat generation in complete feed can be demonstrated by a simple comparison of temperature development measured with temperature logs. The comparison showed that FreshFoss is more effective at reducing heat generation in complete feed than pure potassium sorbate.



Kristensen, 2018. Stabilisering af grovfoder. KvægInfo 2565.

Kristensen, 2019. Screening af additiver til stabilisering af grovfoder. KvægInfo 2578.