Up to 7 Days Okay for Collecting Blood for BSTP
I was just reading an article about heat stress on dams effects their calves. The short story on that is that heat-stressed dams have smaller calves and their calves absorb antibodies from colostrum less efficiently than their counterparts from non-heat-stressed dams.
But, one of the figures jumped out at me. It reported values of total protein in calves blood by age in days. The protein values were virtually constant for the first 7 days. Thus, this is further evidence that when collecting blood for checking on how well a colostrum management program is working we can obtain reliable values from blood out to 7 days of age.
Tao, S, APA Monteiro, IM Thompson, MJ Hayen and GE Dahl, "Effect of late-gestation maternal heat stress on growth and immune function of dairy calves." Journal of Dairy Science 95:7128-7136 (December, 2012). Figure 1 Effect of heat stress and cooling during the dry period on hematocrit and plasma total protein of neonatal calves during the first 28 days of age.