The Evaluation of Reproductive Performance in Dairy Herds

The routine monitoring of the efficiency of reproductive programs is necessary in large-scale dairy herds in the 21 century. The importance of the economic evaluation of these programs is increasing, as well, since many thousands of euros are spent on reproductive management on a farm. However, different interpretations of reproductive indices cause difficulties among professionals when comparing the parameters of their farms to that of another dairy. Last, but not the least, proper and uniform interpretation of these parameters is a prerequisite in performing correct economic evaluations. Some indices (e.g. calving interval) are classically used for monitoring some aspects of cows’ fertility, however they are less adequate to evaluate the reproductive performance of a farm as a whole. Moreover, variations can be observed in the calculation approaches of certain reproductive parameters among herds, and the figures may be further biased due to the exclusion of some group of animals or the use of a hormonal synchronization program. In this study, the authors present the main reproductive indices from a practical point of view and a more comprehensive way of calculating the indices is shown. The advantages and disadvantages of each parameter are also discussed. Special attention is paid to the possible errors which may lead to the miscalculation and misinterpretation of the parameters.