Research shows a calf’s colostral antibody requirement for adequate passive transfer is about 80 to 100 grams. However, don’t assume a colostrum replacer with that level or more will deliver adequate passive transfer.

A North CarolinaStateUniversity study in the June Journal of Dairy Science found that calves fed two or three bags of a commercial colostrum replacer had much lower serum total protein and serum IgG concentrations than calves fed 4 quarts of fresh colostrum. As a result, they had significantly higher rates of failure of passive transfer (please see the table below).

Bottom line: Look beyond the label. Choose products based on proven research, says Geof Smith, North CarolinaStateUniversity veterinarian.

 

 

Group

Average

serum IgG

mg/dL

Average serum 
protein

g/dL

Failure of

passive
transfer1 (%)

4 quarts fresh colostrum

(IgG concentration not available)

1,760

 

5.4

 

5

 

Two bags colostrum replacer

(equivalent to 90 grams of IgG)

750

 

4.4

 

95

 

Three bags colostrum replacer

(equivalent to 135 grams of IgG)

910

 

4.7

 

76

 

 

1Failure of passive transfer was defined as a serum Igg concentration less than
1,000 mg per deciliter. Source: June 2007 Journal of Dairy Science, page 2905-2908.