Publikationsdatenbank

Corpus luteum diagnostic via ultrasound:
a viable tool for treatment decisions in Ovsynch protocols? (2024)

Art

Vortrag

Autoren

Hölper, M. (WE 19)

Bretzinger, L. (WE 19)

Randi, F.

Heuwieser, W. (WE 19)

Borchardt, S. (WE 19)

Kongress

6th International Conference on Uterine Disorders and Corpus Luteum Function

Wroclaw, 09. – 12.09.2024

Quelle

Sprache

Englisch

Kontakt

Tierklinik für Fortpflanzung

Königsweg 65
Haus 27
14163 Berlin
+49 30 838 62618
fortpflanzungsklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Reproductive failure in dairy cows is often associated with the absence of a functional corpus luteum (CL) at initiation of a timed artificial insemination (TAI) protocol, e.g., Ovsynch. Circulating progesterone (P4) concentrations > 1 ng/mL are indicating the presence of a functional CL and are beneficial at the start of TAI protocols for, e.g., luteal regression after prostaglandin F2α (PGF2α) treatment as part of the Ovsynch protocol and subsequent conception rate. Furthermore, sufficient P4 concentrations at the start of TAI protocols are associated with improved oocyte quality, reduced probability of double ovulations and subsequent twinning rates. The accurate diagnosis and interpretation of luteal structures in a feasible way is of utmost importance for practitioners in the field, as treatment decisions or protocol alterations may be chosen based on these diagnostic outcomes. Therefore, we compared CL size via ultrasound with circulating P4 concentrations at protocol initiation in order to evaluate if ultrasound deems as a viable diagnostic tool and to create potential thresholds for optimized CL assessment.
As part of a larger study (Hölper et al., 2023), cows subjected to different Ovsynch protocols (n = 1,056) received transrectal ultrasound (Easi-Scan:GO, IMV Imaging) assessment of the ovaries in order to determine the absence or presence and size of a CL. Blood samples were collected at protocol initiation by venipuncture of the coccygeal vessels. Serum P4 concentrations were determined by an enzyme labeled chemiluminescent competitive immunoassay (Immulite Progesterone Enzym, Siemens Healthcare). To define reference criteria for identifying cows with a functional CL based on the CL diameter, we used a receiver operating characteristic (ROC) analysis. The continuous variable was CL diameter, and the classification variable was P4 concentration > 1.0 ng/mL.
The overall accuracy to identify a functional CL using transrectal ultrasound was 87.2%. The ROC analysis provided an area under the curve (AUC) of 0.901, which can be considered a highly accurate result (Swets, 1988). The optimum cutoff was a 20 mm diameter of the CL. Sensitivity and specificity was 89.6 and 80.0%, respectively. The positive predictive value was 92.8%. The negative predictive value was 73.1%.
In conclusion, transrectal ultrasound examination is suitable for determining functional CL if a diameter of 20 mm is considered as threshold. Therefore, potential modifications to the Ovsynch protocol such as the addition of a second PGF2α treatment or the application of an intravaginal P4 releasing device, may be considered based on ultrasound CL assessments.