Accuracy of rectal palpation and of a rapid milk progesterone enzyme-immunoassay for determining the presence of a functional corpus luteum in subestrous dairy cows.

The accuracy of rectal palpation and of a rapid milk progesterone enzymeimmunoassay (EIA) for determining the presence of a functional corpus luteum (CL) in subestrous dairy cows was investigated, using the results of a radioimmunoassay (RIA) for progesterone in skimmed milk as the "gold standard". The ovaries and uterus of each of 359 subestrous cows from 32 dairy herds were palpated per rectum, the presence or absence of a functional CL was predicted, and a milk sample was collected for analysis by both the rapid EIA and the RIA.The nine clinicians participating in the study had a combined sensitivity of 82.6% and specificity of 52.6%, compared to the EIA which had a sensitivity of 90.3% and a specificity of 84.2% for predicting the presence of functional luteal tissue.It was concluded that the technique of rectal palpation was inaccurate at assessing the functional (progesterone-secreting) status of ovarian structures. In addition, a qualitative EIA was as sensitive and more specific than rectal palpation in predicting the presence of a functional CL in the subestrous cow.