TDK conference 2017

Reproductive disorders are responsible for the largest economic losses in Hungarian dairy herds among the herd-level animal health problems, therefore, the introduction of new management measures that improve reproductive results is crucial. Methods of early pregnancy diagnosis are used to enable earlier reinsemination of open cows, and to get cows in calf earlier after calving. The aim of our study was to compare the reproductive results in Hungarian dairy herds before and after the introduction of pregnancy-associated glycoprotein (PAG) tests. The reproductive data of 2 719 cows from ten Hungarian dairy herds were analysed by mixed-effects models. The analysed reproductive indices were the breeding interval and the calving to conception interval. Considering the entire cow population, reproductive results did not improve following the introduction of PAG tests (p > 0.05). However, in primiparous cows, the calving to conception interval was reduced by 6.7 days after the introduction of PAG tests (95% confidence interval: 0.2 – 12.7 days, p = 0.04). In multiparous cows, reproductive results did not improve after implementing PAG tests (p > 0.05). Our study based on a large cow population indicated that calving to conception interval improved in primiparous cows only, therefore, under practical circumstances only these cows experienced shorter calving interval and better economic results.