Dairy cows usually experience reduced feed intake during the transition period, which results in a negative energy balance and increased susceptibility to "opportunistic" pathogens.
Immediately after calving, cows typically switch to a higher grain diet to increase energy intake, contributing to a more acidic environment in the rumen.
Both of these scenarios may warrant the use of a direct-fed microbial.
"Direct-fed microbials (DFM) are a source of live, naturally occurring microorganisms used as feed additives in the dairy industry," says Peng Ji with the Miner Agricultural Research Institute in Chazy, N.Y. "DFM are primarily composed of beneficial bacteria and live fungi (yeast), and have been recommended for use in cattle to mitigate rumen dysfunction and the effects of being off-feed, and to improve feed efficiency, cow health, and production performance."
For more information, read "Are you considering direct-fed microbials for your transition cow?" in the January 2012 Miner Farm Report.