Ask the Expert: Dr. Neil Michael

Q: We have noticed a decline in colostrum quantity in late summer/early fall.  Is this common and why do we see this seasonal trend?

It is quite common for producers to experience lower quantities (and often quality) of colostrum harvested from animals calving August through October. Knowing that colostrum production begins as early as four to five weeks prior to calving, we can connect these occurrences to some common influencers on animals that were dry during the heat of the summer months (June through August).

Researchers have found that animals experiencing heat stress are likely to have severely depressed immune systems as a result of decreased intakes and high metabolic needs of the developing calf. As a result, these animals are not capable of producing the quantity of IgG compared to animals with normal colostrum production. Additionally, gestation length is often shortened during heat stress months, resulting in calves that are more likely to experience failure of passive transfer.

Producers can alleviate seasonal decreases in colostrum quantity and quality from heat stress by focusing on the following areas:

• Shade for all dry animals and cooling for prepartum cows
• Additional supply of clean water sources for dry groups
• Bunk management to prevent spoilage of feedstuffs and optimize intakes
• Increased dry days by five to seven days to avoid shortened dry periods that can occur during summer months
• Adequate bunkspace (more than 30 inches) and avoid moves during the dry period
• Close monitoring colostrum quality and use of Secure® calf colostrum replacer as necessary