Thursday, March 20, 2014

Saving Time Checking Colostrum
for Antibody Concentration

Here is the proposal. When we check colostrum for antibody concentration write down the value (either from Colostrometer or Brix refractometer) and the animal ID. If we assume that this animal will be consistent in her production of colostrum from lactation to lactation, then we can skip checking her colostrum in subsequent lactations - just use the number from the previous one. 

One significant problem with this time-saving procedure is the time involved in both recording and retrieving the information. In my experience both of these cow-side tests require so little time that the processes of handling the data are very likely to overwhelm any time saving running the test.

For this idea to work well then the major factor influencing the concentration of antibodies in colostrum needs to be the genetic profile of the dam. We need to rule out (1) leaking colostrum before calving and before colostrum collection, (2) variations in natural exposure to pathogens over time, (3) variations in vaccine-driven controlled exposure to pathogens, (4) variations in seasonally related dry cow exposure to daylight, (5) variations in length of interval between calving and first milking, and (6) variations in levels of heat stress of cows before calving. 

Given that all of these factors may vary for each cow my best guess is that genetics would only predict somewhere between 20 and 30 percent of the variation of antibody concentration in colostrum. 

Thus, while saving time by not having to check each cow's colostrum might some initial attractiveness the reality of dairy farm operations suggest that this could be an elusive goal.

However, if anyone knows of one or more dairies that consistently record colostrum quality values and animal ID's it would be instructive to use these data to put some numbers to this relationship.

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