DIAGNOSTIC-ACCURACY OF ESTIMATING THE NUMBER OF CL AND OVARIAN VOLUMETO PREDICT SUPEROVULATORY RESPONSE IN DAIRY-CATTLE

The superovulatory response of 44 dairy cattle was assessed by estimat ing the number of CL and ovarian volume per rectum before non-surgical recovery of eggs. The study included the recovery of greater than or equal to 3 total eggs and greater than or equal to 2 viable/transferab le embryos which were then used retrospectively to determine the diagn ostic accuracy of rectal palpation in predicting superovulatory respon se. When <5 CL were palpated, the specificity (SP) of predicting the r ecovery greater than or equal to 3 total eggs or greater than or equal to 2 viable embryos was <0.5. The diagnostic accuracy of estimating t he number of CL was high (both sensitivity (SE) and SP were >0.5) when 5-12 CL were palpated. The Receiver Operating Characteristic (ROC) cu rves demonstrated that estimating the number of CL was more accurate t han the ovarian volume in assessing superovulatory response. The best cutoff point. where fewest mistakes were made, was when 9 CL were palp ated. At this point of maximum accuracy, the likelihood ratio for a po sitive test result in the recovery of greater than or equal to 2 viabl e embryos was 6.5 and that of a negative test result was 0.3. In concl usion, it was shown that the estimation of the number of CL per rectum in order to predict the recovery of greater than or equal to 3 eggs o r greater than or equal to 2 viable/transferable embryos was diagnosti cally optimized when 5-12 CL were palpated.