Colostrum should look like and have the consistency of melted vanilla ice cream. Runny, thin colostrum or colostrum mixed with blood are signs of poor quality. To test for quality use a colostrometer.
Calves that have a total protein concentration greater than 5.5g/dL have received adequate colostrum. Testing can occur from six hours after the first colostrum feeding to one week of age. Your veterinarian can do random blood tests, which is good feedback on the effectiveness of your colostrum management.
Colostrum samples can be sent for testing. Bacteria counts should be less than 100,000cfu/mL. High bacteria counts are associated with poor colostrum absorption in the calf. Colostrum may also become a source of infection.
If your herd is being screened for Jöhnes, calves should be fed colostrum from pre-selected “colostrum donors”.