Calves with Sam

How Long with Colostrum Keep in the Refrigerator?

This was the question in my e-mail box this morning. In a nutshell this is my reply.

Shelf life of refrigerated colostrum depends on:

• inoculation level before refrigeration
• colostrum temperature going into the refrigerator
• temperature of the refrigerator
• presence or absence of food preservative

The person asking the question does not have inexpensive access to a lab that can do bacteria cultures. That is unfortunate because taking samples and incubating them to grow bacteria is great scientifically sound way to get guidance for this question.

I have tried this "on-farm" method. Honestly, it is very insensitive to small differences in bacteria counts. But, it goes like this:

1. Fill a bottle with fresh colostrum as per usual protocol for the dairy.

2. Take a good smell of it - what does the fresh colostrum like?

3. Next day, take the bottle out of the refrigerator, stir the contents, smell again. You are looking for an "off" odor that would indicate bacteria growth. If it still smells fresh, put it back on the shelf.

4. Next day, repeat the stir and smell routine. Many dairies will find the colostrum has spoiled by the second day.

5. Next day if still okay, repeat the stir and smell routine. Only a few dairies will pass this test by the third day.

6. Repeat until it spoils.

A couple of resources to check if it smells bad by the second day:

1. Click Reducing Coliform Counts in Colostrum

2. Click Putting the Brakes on Bacteria Growth in Colostrum