Increased milking frequency during partial
or whole lactations increases milk yields, but
generally reduces percentages of milk fat and
protein. Because of greater milk volume, total
fat and protein are not reduced. Combining
bovine somatotropin (bST) with increased
milking frequency is additive. In other words,
milk increases in response to both factors. In
some studies, increased milking frequency
during early lactation improves udder health, as
evidenced by reduced somatic cell scores.
Reproductive efficiency generally declines
when examined on whole herd basis. When
examined in single herds with or without bST,
pregnancy rates may not be reduced because of
increased milking frequency, and in some cases
may be improved.