Acta Vet. Brno 2008, 77: 59-64

Use of Carazolol at Pre-Synchronized Timed Artificial Insemination in Cows

Ş. M. Pancarci1, Y. Öztürkler2, Ö. Güngör1, C. Kaçar1, S. Yildiz2, D. Kaya1

1Department of Obstetrics and Gynecology and Reproduction,
2Department of Artificial Insemination and Reproduction, Faculty of Veterinary Medicine, University of Kafkas, Kars, Turkey

Received June 26, 2007
Accepted December 19, 2007

Efficacy of the β-adrenergic receptor blocker (carazolol) at Timed Artificial Insemination (TAI) was investigated. Cows (n = 73) were pre-synchronized with two PGF injections given 14 d apart to initiate the Ovsynch protocol at early and middle luteal stages 14 d later, and received injections of GnRH and PGF seven d apart followed by GnRH 48 h later, and TAI 16 - 18 h later. Corpus luteum (CL) was detected via rectal palpation at the beginning of the Ovsynch protocol. Carazolol (Treatment I; n = 41) or physiologic saline (Treatment II; n = 32) were administered via jugular vein five min before TAI. Uterine tone was determined prior to infusion and at TAI via rectal palpation. Pregnancies were diagnosed with transrectal ultrasonography 40 ± 7 d after TAI. Uterine tone was 2.8 (1.4 - 5.3) times higher (P < 0.01) in Treatment I than that in Treatment II at TAI. Increase in uterine tone was affected by treatment × CL × parity (P < 0.05), and 66.7%, 75%, 52.6%, 100% and 16.7%, 33.3%, 25%, 28.6% in primiparous cows with CL and without CL, and in multiparous cows with CL and without CL in Treatments I and II, respectively. Pregnancy rates did not differ between treatments I (34.2%) and II (40.6%). In conclusion, no beneficial effect of carazolol administration prior to TAI was found except for the increased uterine tone.