Identification of nonpregnant dairy cows early after AI improves reproductive efficiency and pregnancy rate by decreasing the interval between AI services thereby increasing the AI service rate. Thus, new technologies to identify nonpregnant dairy cows and heifers early after AI may play a key role in management strategies to improve reproductive efficiency and profitability on dairy farms. Chemical tests for early pregnancy diagnosis that use qualitative measures of pregnancy-associated glycoproteins (PAGs) originating from the placenta have been developed and commercialized. Because PAGs are produced specifically by the placenta, the presence of PAGs in blood can be used to accurately determine pregnancy status.
Few studies have compared factors associated with PAG levels in blood and milk of dairy cows early in gestation and the impact these factors may have on the accuracy of pregnancy diagnosis. At the 2015 Western Dairy Management Conference, UW-Extension Dairy Cattle Reproductive Specialist Paul Fricke discussed results from an experiment conducted to assess factors associated with PAG levels in plasma and milk during early gestation in Holstein cows and to determine the accuracy of pregnancy outcomes based on PAG levels in plasma and milk compared to pregnancy outcomes based on transrectal ultrasonography. To learn more about the presentation, please view the presentation or the paper.