Publikationsdatenbank

Effect of progesterone supplementation using 2 different intravaginal devices during timed artificial insemination in lactating dairy cows (2023)

Art

Vortrag

Autoren

Frenkel, Rosa (WE 19)

Hölper, Marvin (WE 19)

Heuwieser, Wolfgang (WE 19)

Borchardt, Stefan (WE 19)

Kongress

European Buiatrics Congress and ECBHM Jubilee Symposium

Berlin, 24. – 26.08.2023

Quelle

Kontakt

Tierklinik für Fortpflanzung

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

Abstract / Zusammenfassung

Objectives
Timed AI programs have contributed to the increase in reproductive performance observed in dairy herds over the past decade. In addition to maximizing insemination rates, timed AI programs provide a unique opportunity for identification of low-fertility cohorts of cows and the implementation of strategies to improve pregnancy per AI (P/AI). For instance, cows without a mature corpus luteum (CL)
at initiation of the synchronization protocol have insufficient concentrations of progesterone (P4) in plasma to support proper growth of the ovulatory follicle, which is considered a major impediment for fertility in high-producing dairy cows. The objective of this study was to determine the effect of progesterone supplementation in 7 d Ovsynch protocol using 2 different intravaginal devices on fertility responses in lactating dairy cows.

Materials and methods
A total of 1,036 Holstein cows from one commercial dairy farm in norther Germany were enrolled into a modified Ovsynch protocol (d 0, 100 µg of GnRH; d 7, 100 µg of cloprostenol; d 8, 500 µg of cloprostenol; d 9, 500 µg of GnRH). All cows received timed artificial insemination approximately 16 h after the second GnRH treatment. Cows were randomly assigned to 1 of 3 treatment groups on a weekly basis: 1) Control: no P4 supplementation (n = 345), 2) P4_1g: a device with 1 g of P4 from d 0 until d 8 (n = 344), and 3) P4_1.55g: a device with 1.55 g of P4 from d 0 until d 8 (n = 347). All cows had their ovaries scanned to determine the presence of a CL at the beginning of the Ovsynch protocol. Vaginal discharge score (VS) was evaluated at d 8. Pregnancy diagnosis was performed via transrectal ultrasonography (d 38 ± 3 after timed artificial insemination) and rechecked on d 80 ± 7 after timed artificial insemination.

Results
There were 39.4 % (419/ 1,064) of cows without a CL at d 0. Treatment affected VS at day 8 with more cows showing purulent vaginal discharge that received an intravaginal device (Control: 0.6%; P4_1g: 32.2%; P4_1.55g: 26.5%). Treatment had no effect on P/AI (P = 0.138; Control: 30.8 ± 3.2%; P4_1g: 34.8 ± 3.2%; P4_1.55g: 39.5 ± 3.4%). There was, however, an interaction of treatment and presence of a CL (15 mm diameter) at d 0 (P = 0.038). Treatment had no effect on P/AI in cows with a CL at the initiation of the protocol (P = 0.712; Control: 35.9 ± 4.1%; P4_1g: 38.6 ± 3.9%; P4_1.55g: 34.2 ± 4.0%). In cows without a CL at the initiation of the protocol (P = 0.016; Control: 26.1 ± 4.3%; P4_1g: 31.3 ± 4.8%; P4_1.55g: 45.1 ± 5.3%) treatment had an effect on P/AI. There was no difference between control and P4_1g (P = 0.412). Cows in P4_1.55g were superior compared to control (P = 0.004) and P4_1g (P = 0.049).

Conclusions
A single ultrasound examination effectively identified a low-fertility cohort of cows based on the absence of CL at the first GnRH injection of the Ovsynch protocol. Supplementation of 1.55 g of progesterone from d 0 until d 8 restored fertility in dairy cows lacking CL to a level similar to that of cows in diestrus.