Using a handheld refractometer to test colostrum quality for healthy livestock

Updated March 22nd 2021

Here at Refractometer Shop we don’t claim to know the meaning of life, but we do know that colostrum quality is key to giving livestock a healthy, meaningful start.

Using a refractometer is a simple way to determine colostrum quality at birth

Foals, calves and lambs with low levels of immunoglobulin are in danger of becoming immunologically compromised and at times are in a potentially life threatening position at birth. Using a refractometer to monitor colostrum quality fed to newborns can help to ensure that these young animals receive enough immunoglobulin, increasing the survival rate of new livestock.

Measurements can be taken using a Bellingham + Stanley "Eclipse" or "OPTi" handheld refractometer, available from Refractometer Shop.

Eclipse optical refractometer for colostrum

The Eclipse handheld refractometer is an easy to use tool designed to measure refractive index, which is often converted into a concentration measurement - in this case colostrum quality. By taking a well-mixed colostrum sample and placing a small drop onto the glass prism and referring to the conversion table below, you’ll be able to easily tell if the sample is poor, adequate or very good.

To take a reading using an optical refractometer you simply open the flap, apply a sample to the glass prism, close the flap and look through the eyepiece. The results will be shown by a shadowed line through the scale. We call this the borderline.

OPTi Digital handheld refractometer for colostrum

For an even quicker and easier method we recommend the use of an OPTi digital refractometer. Simply apply the sample to the prism dish & press “READ”. It really is that simple.

No look-up tables or conversions necessary, the OPTi will do the work for you before telling you in English whether the sample is good to use or not.

The OPTi Digital Handheld Refractometer for colostrum also comes with 2 additional preprogrammed scales: Total Solids of Waste Milk, and Brix. These scales can be swapped at any time thanks to the onboard library of 50 common refractometer scales.

The use of a refractometer allows the level of immunoglobulin to be assessed quickly (in seconds) and effectively and immediate treatment can follow. The refractometer is an invaluable and simple aid to securing these measurements without the need for large, valuable amounts of sample.

Colostrum quality conversion table

BRIX % IgG Conc. g/l Colostrum Quality
<10-15% 0-28 Poor
15-20% 28-50 Borderline
20-30% 50-80 Adequate
 >30% >80 Very Good


More for your money

Don't forget that your new OPTi refractometer contains a library of common scales which are all accessible for the user. Industrial scales such as Ethylene Glycol or food and beverage scales like fructose or water in honey. Take a look at our blog on changing scales for more information.

To learn about Eclipse and OPTi refractometer click here.

Colostrum quality refractometers