Development of production and economic indicators of milk production in the Czech Republic between 2006 and 2015 From 2006 to 2015, milk yields of cows in the Czech Republic and in the group of selected farms increased. In addition, the volume of marketed milk per cow and the number of weaned calves also increased whereas the average age at first calving was reduced. The average somatic cell count clearly decreased during the last four years. In the period from 2006 to 2015, the cost of milk production in surveyed farms increased by 10.8 thousand CZK (17%) per cow per year and when expressed per liter of milk sold, it ranged from 8.5 to 9.4 CZK.