The average age that Holsteins are calving continues to be a number that is improving as we look at dairy herd management records.
In summarizing DRMS data for Holsteins in Pennsylvania, we find that age at calving continues to drop each year. Back in 1985 when we were studying this as a part of an Extension program, average age of Holsteins calving for the first time in Pennsylvania was 26.9 months. In 2011 it was do wn to 25.5 and as you can see from the graph, it is a number that each year decreases. In the past 4 years this decrease has been smaller, but that is to be expected as we approach a recommended goal of 23 to 24 months.
Age at first calving is an important indicator for herds to monitor as it can be a large factor in your average cost of raising heifers. Keeping un-bred heifers in the heifer barn often costs $50 to 70 a month, and extended calving ages can lead to large increases in annual replacement costs for the dairy farm. Current recommendations are for age at calving to be 23 to 24 months of age.