ESTIMATION OF ECONOMIC VALUES FOR FERTILITY, STILLBIRTH AND MILK PRODUCTION TRAITS IN IRANIAN HOLSTEIN DAIRY COWS

The objective of present study was to derive the economic values for number of inseminations to conception, calving interval, milk yield and stillbirth, using economic data of 10 Iranian Holstein herds. The economic values were derived by using the profit function methods and differentiating a profit equation with respect to the traits of interest. The cow fertility costs herd amortization or replacement cost and cow feed cost were included in the profit function. The average of feed cost per cow per day was 8.65 USD. The total feed cost comprised 61 percent of milk production, 23 percent of maintenance, 12 percent of pregnancy and 4 percent of growth. In calculation of cow feed cost, the estimated cost for each Mcal and per g protein of feed were 0.0006 and 0.165 USD, respectively. The replacement cost of each heifer per cow herd was 1719 USD. The average cost of each insemination was 30 USD. The estimated economic values for the number of insemination, calving interval, milk yield and one percent unit of stillbirth, were -82, -2.08, 0.193 and -1.27 USD per cow/per year, respectively. The results of the current study suggested that improving the number of inseminations, calving interval, milk yield and stillbirth will have a positive effect on the profitability of Iranian Holstein cows.