The first 24: Get calves off to a great start with colostrum

Posted on July 20, 2023 in Dairy Performance
By Bethany Dado-Senn, Ph.D., and Lucas Mitchell, Ph.D.

The birth of a calf signals the start of a 24-hour race to ensure the foundation of a strong immune system.  During a breakout session at the Vita Plus Midwest Dairy Conference, we discussed what happens in the first few days of a calf’s life and strategies to maximize success in passive transfer of immunity.

Between 0 to 6 hours of life, the calf should be fed colostrum.  Colostrum is the first milk from the dam. It is high in fat, protein, and immune factors like immunoglobulin G (IgG), the most commonly discussed benefit of colostrum.  This colostrum should be harvested hygienically, focusing on clean milking and feeding equipment, and quickly to preserve IgG concentration.

After harvest, colostrum should be fed within 30 minutes, stored in a refrigerator for up to 24 hours or stored in a freezer for up to one year.  Some key concepts in colostrum storage include choosing the ideal storage container (ideally an air-tight bag or small bottle) and ensuring proper storage temperatures (40 degrees F for the refrigerator and -20 degrees F for the freezer).  When it’s time to feed the colostrum, warm it to 105 to 110 degrees F using a 120-degree F water bath.

Once the colostrum is warmed, it’s time to feed it to the calf.  The concepts of colostrum delivery are based on the 4 Qs: quality, quantity, quickly and sQueaky clean.  Quality colostrum has an IgG content of 50 grams per deciliter or more, which is correlated to a Brix score of 22%.  Brix is a measure of total solids in a liquid, and it’s evaluated on-farm using an optical or digital refractometer.

As part of the breakout, we practiced using refractometers to measure colostrum quality and discussed what we would do with the tested colostrum based on the Brix value.  Colostrum with a high Brix score often gets fed to replacement heifers while colostrum with a lower score is either dosed with colostrum replacer, pooled with other colostrum or fed to bull calves.

The benchmarks for colostrum quantity are 10% of bodyweight, which ranges from 3 to 4 quarts for smaller to larger calves, respectively.  Quick colostrum delivery should occur within 2 hours of birth to maximize absorption of IgG.

Next, around 6 to 12 hours after the first feeding, calves should be fed another 2 to 4 quarts of transition milk or lower quality colostrum (<19% BRIX).  Feeding additional transition milk improves intestinal growth and development, improves calf health, and aids in calf growth potential.

Finally, between 24 hours to 3 to 4 days of life, a serum sample should be collected from calves to determine the success in passive transfer of immunity.  According to the Dairy Calf and Heifer Association, target passive immunity is at an equivalent serum total protein of 6.2 grams per deciliter or higher, with good between 5.8 to 6.1, fair between 5.1 to 5.7 and poor less than 5.1 grams per deciliter.

During the breakout, we watched a video on how to collect the serum sample and then used the refractometer to measure the serum total proteins and determine if the calf had adequate passive immunity.  If the calf did not meet targets, we discussed what aspects of the 4 Qs might have been the cause for poor passive transfer.

Click here to download Dado-Senn and Mitchell’s PowerPoint presentation from the Vita Plus Midwest Dairy Conference.

Category: Animal health
Calf nutrition
Colostrum management
Dairy Performance