Abstract

A commercial feed concentrate and a mineral mix with excessive amounts of fluoride were introduced into a Holstein dairy herd with an average milk production well above national standards. Milk production decreased drastically, and during the following 6 years the deficit in milk production in the herd ranging from 52 to 120 milking cows was 1.5 million Kg (3 1/4 million lbs.). The tolerance levels set by the National Academy of Sciences for fluoride ingestion by lactating cow were found to be inadequate.