Why the Rush to Feed Colostrum?
A recently reported study fed colostrum at 45 minutes, 6 hours and 12 hours after birth. All colostrum was tube fed. The calves received 7.5% of their birth weight in colostrum.
For example, a 90 pound calf received about 3.25 quarts of colostrum. At 62g/l concentration of antibodies in the colostrum this 3.25 quarts came to 190g of antibodies in this feeding. The average for all calves was right around 195 to 200g at first feeding.
From blood sampling they determined the efficiency of absorption of the antibodies (IgG).
The average efficiency of absorption of antibodies were (by time of feeding):
45 minutes 52%
6 hours 36%
12 hours 35%
In case you didn't want to figure out the amount of improvement, the 52% efficiency of absorption for 45 minutes represents a 44 percent improvement compared to the 6 and 12 hours feeding procedures.
Fisher, A. J., and Others, "Effect of delaying colostrum feeding on passive transfer and intestinal bacterial colonization in neonatal male Holstein calves." Journal of Dairy Science 101:30299-3109 April 2017.