A client stumbled upon an unexpected revelation while collecting colostrum quality data using the farm’s new toy, a digital Brix refractometer. Over the course of 2 weeks, we noticed excessive colostrum variability from cow-to-cow. The calving pen was not experiencing a calving slug so cow comfort, bunk space, late pen moves were not concerns at the time. Our first thought was to run serum proteins on close-up cows. Fortunately the Misco digital refractometer can also run serum proteins. Serum protein levels were running in the low 6’s for mature cows and mid 5’s for first calf heifers. Normal serum protein levels should be 6.8g/dL. We normally see low heifer protein levels when commingled with cows due to lower dry matter intakes when consuming a dry matter package designed for mature cows. If we raise protein levels, we assumed that colostrum quality would improve as well. A half pound of blood meal was added to the ration and the result was a bump in serum proteins of 0.5g/dL. Unfortunately though, we still had excessive variability in our Brix colostrum readings.
What was going on? Calves are removed from the cows before they have an opportunity to nurse. That was not the problem. Fresh cows were moved from the maternity pen to the fresh cow pen once a day. Fortunately, our client also recorded first milking times after calving and there was our direct link. The cows that had a longer interval between calving and first milking had lower Brix colostrum readings. It truly is amazing how rapidly, colostrum quality degrades inside the udder. We made the adjustment to move cows from the maternity pen 3 times a day to correlate when fresh cows move to the parlor. And just that quickly, the colostrum variability issues disappeared with most colostrum readings in the mid-20’s%.
This story reinforces important colostrum management concepts. As quickly as colostrum quality degrades, if you cannot collect colostrum right away, use a high quality colostrum replacer or high quality Brix tested colostrum from an earlier calving.