Newborn calves receive their antibodies, which will help them confront the bacteria and diseases of the world, through passive transfer. In other words: they need to be fed with good quality colostrum within the first hours of their life, in order to develop a healthy and strong immune system.
A new, simple and pocket-sized tool will now help to assess colostrum quality and therefore lower the risk of failure of passive transfer. The H&L Refractometer works by using light to determine the density of a liquid. Meaning, a sample of the examined liquid such as the colostrum or even blood serum is shined through with a beam of light. Protein in the liquids will cause the light to bend, which in turn will be measured by the refractometer. The tool defines the amount of light that is being bent and therefore estimates the concentration of immunoglobulin (IgG) in colostrum or of total solids in blood serum. The result is displayed in Brix (°Brix).

Colostrum with an IgG concentration of 50 mg/ml is considered high quality colostrum. This value corresponds to a Brix reading of 22° and more. Samples with a Brix reading below 20° are considered insufficient and should therefore not be fed to newborn calves on their first day of life. However, this milk still provides rich nutrition for older calves.

As mentioned above, the H&L Refractometer does not only determine the colostrum quality but can also be used to test the blood serum. As a result, this test will determine whether the passive transfer of immunity was successful or not. If the serum contains 10 mg/ml of IgG (7.8 °Brix), the passive transfer can be seen as effective.

Furthermore, the H&L Refractometer can be helpful, when it comes to feeding whole milk. The dry matter concentration in milk can vary from batch to batch, depending on the amount of colostrum or when water has been added to the milk when milk lines have been flushed in between milkings. In this case, the refractometer measures solids in the milk, so that the nutrient level can be adjusted by adding powdered milk if necessary. To fortify the whole milk with powder, the new Milktaxi 4.0 offers the option SmartMix, an easy calculator which tells the user how much milk replacer needs to be added.
With the H&L Refractometer the concentration of solids in powdered milk can be tested as well, in order to maintain the correct mixing proportion and therefore the required level of nutrients.