Measuring Colostrum Quality
Posted on November 9, 2012 in Starting Strong - Calf Care
Failure of passive transfer is one of the biggest factors affecting calf health and mortality. Not only is it important to make sure your calves are getting colostrum in a timely manner, but it is also important that the colostrum you are feeding is of the highest quality. How do you evaluate colostrum quality? Several great devices are available to make sure the colostrum you are feeding your calves is getting them off to the right start.
Currently, only about 13 percent of U.S. farms perform any type of colostrum quality evaluation with the colostrometer being the most commonly used type of evaluation.
A colostrometer is a glass hygrometer that is placed in a sample of colostrum at room temperature. The instrument measures the specific gravity or density of the colostrum. A dense colostrum sample will have a higher concentration of important immunoglobulins. Depending on the density, the colostrometer will either sink or float. The tube is color-coded, so you can easily see whether the colostrum is good (green) or not-so-good (red).
However, colostrometers can be inaccurate if the temperature of the colostrum is not at room temperature. If the colostrum is warmer than room temperature, there can be false negative readings and a lot of high-quality colostrum can be discarded.
The popularity of colostrometers is fairly high because they are easy to use and inexpensive. But, colostrometers are incredibly fragile and break easily when used on-farm. That, coupled with the temperature sensitivity problem, makes colostrometers less than ideal for on-farm evaluation.
A newer product to the market is the Brix refractometer. Unlike the colostrometer, the Brix refractometer is not temperature sensitive. It measures the total solids content in colostrum, which is directly correlated to the amount of IgGs present.
“A Brix measurement of at least 22 percent solids best predicts high-quality colostrum,” says Sandra Godden, a professor with the College of Veterinary Medicine at the University of Minnesota.
Recent research has shown that although Brix refractometers are not perfect, they offer improved accuracy over previous colostrum evaluation techniques. Refractometers can be as cheap as $50 and top-of-the-line digital models can cost more than $150.
While these devices are valuable estimating colostrum quality, it is still important to properly harvest and store colostrum, otherwise quality colostrum can be compromised.
“Clean matters,” says Godden. “Dirty, contaminated equipment is one important source of colostrum contamination.”
A second contamination source is bacterial growth during storage.
Properly cleaning and disinfecting the teats and milk equipment during the milking process and transferring colostrum into clean containers are two of the easiest ways to keep colostrum clean. Stored colostrum should either be frozen or refrigerated immediately and used up over a couple days post-collection.
Starting Strong - Calf Care