Association of luteal blood flow with follicular size, serum estrogen and progesterone concentrations, and the inducibility of luteolysis by PGF2αin dairy cows.
The aim of this study was to investigate the compatibility of the visual evaluation result of the blood flow characteristics and the blood flow measurements of the CL and the predictability of the responses given by corpora lutea with varying levels of blood flow to an induction of luteolysis by a PGF2αinjection and to determine the possibility of increase in serum estrogen and progesterone concentrations in parallel with increased luteal blood flow (LBF). The cows, bearing a CL (n = 60; postpartum 35 days), were injected with PGF2αand were monitored for signs of estrous following the first injection. The cows, which did not show estrous signs, were examined for the presence of a CL on Day 14, whereas those that showed signs of estrous were examined on Day 10 following the onset of estrous. The level of LBF was visually graded as + (low; GI), ++ (medium; GII), +++ (high; GIII), and ++++ (very high; GIV). Immediately after the examination of LBFs, a second intramuscular injection of PGF2αwas injected. In the cows, which were determined to be in estrous, the diameter of the Graafian follicles was measured by B-mode ultrasonography. Subsequently, these animals were artificially inseminated. The animals, which did not show estrous after the second injection, were examined as previously described and monitored for signs of estrous. A strong correlation (r = 0.654; P < 0.001) was determined to exist between the results of the visual examination of the images and the results obtained for the LBF area with the use of the Pixel Flux software. GIII (0.83 ± 0.15 cm2) and GIV (1.03 ± 0.48 cm2) were found to differ from GI (0.47 ± 0.23 cm2) and GII (0.51 ± 0.12 cm2) for the size of the LBF (P < 0.001). Serum progesterone levels in groups (GI, GII, GIII, and GIV) were determined to be 4.44 ± 2.42 ng/mL, 6.03 ± 2.37 ng/mL, 7.01 ± 2.94 ng/mL, and 7.17 ± 1.69 ng/mL, respectively. The comparative evaluation of the study groups showed that the groups did not statistically differ for the period between PGF2αinjection and the onset of estrous, mean Graafian follicle size and estrogen levels. No direct correlation existed between these reproductive parameters and LBF.
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, University of Kafkas, Kars, Turkey. Electronic address: semra-kafkas@hotmail.com.
Semra
S
Kaya
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, University of Kafkas, Kars, Turkey.
Cihan
C
Kaçar
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, University of Ataturk, Erzurum, Turkey.
Bülent
B
Polat
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, University of Ataturk, Erzurum, Turkey.
Armağan
A
Çolak
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, University of Kafkas, Kars, Turkey.
Duygu
D
Kaya
Department of Biostatistics, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey.
I Safa
IS
Gürcan
Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Heinrich
H
Bollwein
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, University of Near East, Nicosia, North Cyprus, Turkey.
Selim
S
Aslan
D000818:Animals; D001783:Blood Flow Velocity / Q000662:veterinary*; D002417:Cattle; D003338:Corpus Luteum / Q000098:blood supply*; D015237:Dinoprost / Q000494:pharmacology*; D004967:Estrogens / Q000097:blood*; D005260:Female; D003341:Luteolysis / Q000187:drug effects; D010120:Oxytocics / Q000494:pharmacology; D011374:Progesterone / Q000097:blood*
D004967:Estrogens; D010120:Oxytocics; D011374:Progesterone; D015237:Dinoprost
Corpus luteum; Cow; PGF(2α); Power Doppler ultrasonography