Monday, October 8, 2018

Do Everything Right and Still Get Failures!
Colostrum Management

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 information on colostrum management:
  • Quality of colostrum fed
  • Quickly - time after birth when colostrum fed
  • Quantity of colostrum fed
What did they find?

  • When calves received excellent management (high quality, fed quickly, volume of 10% or more birth weight) - still 14% still had passive transfer failure (<10g/L).
So, how come this finding?
  1. One possibility is that the subject farms lied - they reported what the farm protocol was rather than what actually was being done. But, there were many farms and many calves - so maybe not such a good explanation for 14% PTF.
  2. A second possibility is sampling and testing error. Only one blood sample was taken from each calf with considerable variation in days between first colostrum feeding and when the blood was drawn. This could account for some of the failures but still 14% is lot to attribute to errors.
  3. A third possibility is genetic variation. Some calves have genetically determined ability to absorb antibodies very efficiently while others are at the other end of the spectrum - poor absorption ability. I not sure how I would go about measuring this. But, given natural variation on all other traits this might be a viable alternative. 
Where do I come down on this question?

While the first and second reasons might account for one or two percent of PTF it is my opinion (note lack of scientific evidence) that genetic variation could play a big role here.

On one hand, as calf care person it is not reasonable to beat ourselves up over wide variation among calves in passive transfer of immunity.

On the other hand, I have a client (130 calves on milk) whose colostrum feeding protocol includes feeding only Brix 23 or higher colostrum as first feeding, nearly all calves receive first feeding before 4 hours after birth and the calves receive 4 quarts at birth, 2 more quarts 6 hours later and another 2 quarts 6 hours after that. Their PTF rate last month (<5.0 g/L) was 5% with an average BSTP of 6.4 g/L.

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

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