Thursday, August 20, 2015

Failure Rate for Calves Nursing Colostrum on Their Own

Yet another study has documented the passive transfer failure rate for dairy calves allowed to nurse from the dam on their own. This is in contrast to hand feeding a known volume of colostrum with a known concentration of antibodies. 

The study included 2,500 calves from 50 dairy farms. Cows were Holsteins, Jersey and Holstein-Jersey crosses.  Blood was drawn between 1 and 7 days of age, refrigerated overnight, centrifuged and the serum separated from the clot within 24 hours of collection. The average blood serum total protein level for 2,500 calves as 5.9 g/dL. Successful passive immunity was defined as a blood serum protein level of 5.5 or greater.

"Calves that were allowed to suckle their dams showed a 44 percent failure of passive immunity."

Can we do a better job when we hand-feed colostrum? One of my clients feeds six quarts of colostrum testing 22 or greater using a Brix refractometer within the first 12 hours of life. As of July 24, 2015 since September 2014 they have tested 756 calves. Ninety-seven percent of these tested at 5.5 or greater.

A. Elizondo-Salazar and Others, "Passive Transfer of immunity in dairy heifer calves on Costa Rican dairy farms," Journal of Dairy Science, Vol.98, Suppl.2, Abstract W23.

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