The BRIX refractometer is a convenient and relatively inexpensive tool that can be used to effectively evaluate colostrum quality on the farm.
This tool measures the solids content of colostrum, which then is extrapolated to estimate IgG content. Previous studies using Holstein colostrum suggested a breakpoint of 21% BRIX be used to indicate high- versus low-quality colostrum.
Calf specialist Jim Quigley with Provimi North America reviewed a study investigating whether this break-point would be the same or different for Jersey colostrum, which varies in the amount and type of solids it contains compared to Holstein colostrum.
The researchers found that Jersey colostrum did, indeed, call for a different BRIX reading to determine quality compared to Holstein colostrum. They recommended a breakpoint of 18% BRIX was the most accurate threshold to determine whether Jersey colostrum was high-quality (> 50 g of IgG/L) or low-quality (< 50g of IgG/L).
To read Quigley"s full evaluation of the study in the latest issue of his Calf Notes newsletter, click here http://dairyherd.com/sites/default/files/CNlatest.pdf.