In Ireland in the 2021 calving season the national calving interval has increased by one day to 388 days, from 387 days in 2020. The best ten percent of the dairy farms have a calving interval of 364 days, the worse ten percent dairy farms have a calving interval of 422 days. The Irish national target is a calving interval of 365 days. The average replacement rate is 19 percent. Of the heifers average 74 percent calved at an age of 22 to 26 months. Of all calvings average 67 percent took place in a six week period, of the top ten percent dairy farms this was 87 percent and of the bottom ten percent of the dairy farms this was 40 percent.