Calves with Sam

Risk of Passive Transfer Failure

Most of us have heard of the Q's related to colostrum management:

Quality

Quantity

Quickly

Recently we have added two more:

Quantify [refers to blood testing baby calves for evidence of antibody transfer]

sQueaky clean [refers to sampling and culturing colostrum for bacterial contamination]

The Quality:Quantity:Quickly trio are often used to assess risk of passive transfer failure.

Quality - less than or equal to 50g/L of IgG's 

Quantity - less than or equal to 10% of birth weight (volume)

Quickly - delayed first feeding more than 4 hours after birth

In 2014 the National Animal Health Monitoring System completed a calf study involving 104 dairy operations in 13 states. This was an 18-month longitudinal study involving 2,545 heifer calves. Holstein calves made up 89% of the population. By herd size, the study included:

• Small (30-99cows)            20%
• Medium (100-499 cows)   32%
• Large (500+ cows)            48%

They collected blood samples to assess effectiveness of passive transfer of immunity from colostrum to calves.

What did they find about failure of passive transfer and colostrum feeding?

Of the calves that failed, 47% had been fed poor quality colostrum!

Especially high risk was simply not feeding enough antibodies. That is easy to do - just use poor quality colostrum and feed too small a volume (e.g., only 5% birth weight or 2 quarts).

Quality assessment is sooooo easy. Less than 1 minute, instant results.

Click HERE for a short instruction sheet for using a Brix refractometer to estimate colostrum quality (antibody concentration). If the link does not work, here is the URL

http://atticacows.com/library/newsletters/ColostrumTestingRefractometerR18119.pdf

Reference: Preweaned heifer management on US dairy operations: Part 2. Factors associated with colostrum quality and passive transfer status of dairy heifer calves." Journal of Dairy Science 101:9185-9198 October 2018.