Colostrum – Monitoring Quality & Prolonging Shelf Life

By Dr Charlie Blackwood

A BRIX REFRACTOMETER is the best way to give your calves the best quality colostrums.
Read the article below then contact us about buying one. You do need to be shown how to use one.

Why do I need One?

It is impossible to tell just by looking, how good the colostrums is. High quality colostrums is critical. In the past we have used a Colostrometer to measure quality. Recently a thing called a BRIX REFRACTOMETER has been found to be even better.

A refractometer, uses light to measure the quality of the colostrums (and sugar content of grapes, grasses etc in other fields)

Advantages of a Brix Refractometer over colostrometer

  • Much more accurate
  • Not affected by temperature
  • Optical ones more robust and compact

Using an Optical Refractometer

It takes a few attempts, but once you have worked it out, they are easy to use.

  • You put 2 drops of the colostrums onto the glass plate, close the cover, point at the light then look through the eyepiece.
  • You will see a blue line and you look at what number the line is on.
  • The higher the number, the better the colostrums.

High readings (>25% Brix) can be a bit blurry to read i.e. the blue-white line is a bit fuzzy. This doesn’t really matter because the low readings are very clear and as long as it’s above 22%Brix, then that is all we are interested in.


Prolonging the shelf-life of colostrum

In the short-term, if colostrum is not fed within 2 hours of collection it should be stored in a refrigerator at 4oC to help prevent bacterial overgrowth. Bacterial overgrowth can directly cause disease in calves and also decrease absorption of antibodies from colostrum.

Multiple small containers, such as milk bottles or Perfect Udder bags, are preferred as smaller volumes of colostrum will reach the desired low temperature more rapidly than a single large volume of colostrum, such as colostrum in a 20 litre bucket. If larger volumes in buckets are unavoidable, ensure these have a lid and are thoroughly cleaned after each use. Colostrum kept in a refrigerator at 4oC will have a shelf-life of approximately 2 days.

The shelf-life of refrigerated colostrum can be prolonged to 5-7 days, using potassium sorbate which should be added as soon as the colostrum is collected. Potassium sorbate is a food preservative used in the human food industry and has been safely and successfully used on many farms in south-west Victoria. It works by inhibiting bacterial growth but it will not make contaminated colostrum “clean again”.

Colostrum still needs to be collected in a hygienic manner to ensure the bacterial load is as low as possible at the outset. Potassium sorbate preservation should be used in conjunction with refrigeration at 4oC to have maximum effect. This method can be very useful during the calving period as it avoids the need for long-term storage such as freezing.

Potassium sorbate solution is added to colostrum at a rate of 10ml per litre of colostrum. It can be obtained from Warrnambool Veterinary in a range of sizes and has an expiration period of 6 months once in solution.

Please contact our vets at Warrnambool Veterinary for more information - call The Farm Desk on 5561 7666