Ellések ellenőrzésének fontossága a halvaszületések csökkentése érdekében tejelő szarvasmarha- állományokban - Irodalmi összefoglaló

Abstract

SUMMARY The successful genetic selection for higher milk production caused a dramatic decline in the reproductive performance of dairy cows all over the world during the last decades. Achievement of optimum herd reproductive performance (calving interval of 12 or 13 months with the first calf born at 24 months of age) requires concentrated management activities, especially during calving and during the first 100 days after calving. There are several factors which may affect reproductive per-formance of dairy cows, however in this review only care¬ful surveillance and assis-tance at calving and their effects on milk production, reproductive performance as well as on newborn calves are discussed. Due to the fact that the cause of stillbirth with a non-infectious aetiology is likely to be multifactorial and difficult calving may explain only about half of them. Therefore it is very important to examine regularly the risk factors of stillbirth, especially in large-scale dairy farms. According to our recent experience, management plays a very important role in decreasing the prev-alence of stillbirth in large-scale dairy farms because introducing a camera system in the calving pen its rate decreased from 7.7% to 5.5%. Predicting the onset of calving in free-stall housing circum¬tances is also very important because by using the Vel’Phone we were able to decrease its rate from 8.6% (data of a 3-year period) to 3.1%. Using group calv¬ing pen instead of individual calving pen can significantly decrease the preva¬lence rate of dystocia, stillbirth, retained foetal membranes and injury of the soft birth canal. Assisted calving with inappropriately timed obstetrical assistance can also significantly negatively affect the prevalence rate of dystocia, stillbirth, retained foetal membranes and injury of the soft birth canal. Therefore, obstetrical assistants also play a very important role in the economy of a dairy farm.