benchmarks By Jaclyn Krymowski for American Dairymen
mong the most important assets a cow can provide to a farm is pregnancy. The value of a single pregnancy varies from farm to farm and has a host of contributing factors. It’s estimated at an average worth anywhere from $250 to over $500, depending on the markets and specific operation. Every day a cow is kept open past an established voluntary waiting period (VWP) her expense increases. The benchmarks a herd should aim for needs to be evaluated in a team effort involving farm owners and managers, veterinarians, and everyone involved in the breeding process. A handful of key reproduction analysis measures can be narrowed down to improve pregnancy success.
Where to look
The big a na ly se s to w atch include pregnancy rate (PR), and conception rate (CR) in both cows and heifers. Daughter pregnancy rate (DPR) is another measure of note is of ever increasing importance in many herds. To get an
idea of where your farm stands on each of these measures, it is a good practice to review the national and state breed-specific herd averages and understand what factors contribute to each. Pregnancy rate is determined either by the number of animals pregnant div ided by the total number of animals eligible for pregnancy within a specific time frame – usually each 21-day cycle – throughout the year. Another way this is calculated is by a herd’s total CR multiplied by the heat detection rate (HDR) or service rate (SR). “Eligible” cows or heifers refers to any animal that is open
past the established VWP and not marked as a “do not breed” animal. According to AgSource Dairy, the annual 2017 PR herd average out of 2509 Wisconsin Holstein herds was 18.1%. Herds in the 80th percentile were as high as 25% for mature cows. Jersey PR statistics were 21% for cows from 127 herds in the state; the 80th percentile was a 28%. Comparatively, heifer conception rates were 59.7% on average with the 80th percentile being 67%. Conception rate is calculated by the number of confirmed pregnant animals by the total number of inseminations. According to the Council on Dairy Cattle Breeding (CDCB) the most recent national average from December 2017, calculated from over 200,000 Holstein cows born in 2015, is 59.7%. The calculation for Holstein heifer CR born in 2016 is 68.7%. For Jersey cows and heifers, the CR is 54.7% and 64.3% taken out * Continued on page 24