REPRODUCTIVE EFFICIENCY IN HIGH-MILKING DAIRY COWS AFTER CALVING

The aim of this work was to determine incidence of calving and postcalving reproduction disorders and their effect on the major parameters of cows reproductive efficiency at dairy farm in the R. Serbia. Total number of 1835 high-milking dairy cows (av. milk production >8500L/305d of lactation) records has been reviewed during one year period, at the large dairy farm in area of Vojvodina (R. Serbia). Normal calving and puerperal period without health problems was observed at 583 cows (27,6%), while different abnormalities during and after calving were recorded in 1252 cows (72,4%). The highest percentages of registered peripartal disorders were dystocia and endometritis (62% and 64%, respectively), affecting almost the same percentage of cows. Peripartal disorders had statistically significant influence (P<0.05) on the increase of number of services/conception (3,5 vs. 2,7, reproductive disorders vs. healthy cows, respectively), prolongation of the interval from first postpartal insemination till conception (110 vs. 57 days, reproductive disorders vs. healthy cows, respectively), and increase of days open period (214 vs. 146 days, reproductive disorders vs. healthy cows, respectively). This results have confirmed increased incidence of reproduction disorders during calving and postcalving period that significantly reduces reproductive efficiency in high milking dairy cows after parturition.