EMG activity of the muscular and stromal layer of the cervix in relation to EMG activity of the myometrium and cervical dilatation in PGF2α induced parturition in the cow

Cervical diameter in relation to uterine and cervical EMG activity in early postpartum dairy cows with retained placentas after PGF2alpha induced calving

“…They were selected on the following traits: a body condition score of 3-3.5 [26], only spontaneous uncomplicated parturitions in their history and carrying a singleton pregnancy with an anterior presentation. Six cows were deemed to be sufficient for this study, based on previous studies using similar physiological parameters and experimental protocol [14,15,24,27]. The use of these animals in this experiment which was a follow-up of a previously described study [24] had been approved by the Ethical Committee of the Veterinary Faculty of Utrecht University (The Netherlands).…”

“…Six cows were deemed to be sufficient for this study, based on previous studies using similar physiological parameters and experimental protocol [14,15,24,27]. The use of these animals in this experiment which was a follow-up of a previously described study [24] had been approved by the Ethical Committee of the Veterinary Faculty of Utrecht University (The Netherlands). The cows were housed in individual stands in the clinical facilities of the veterinary faculty from their arrival until the start of the experiments.…”

“…They underwent surgery 10-14 days before parturition was induced with a synthetic PGF2a analogue (Prosolvin 1 , 2 ml i.m., Intervet, Boxmeer, The Netherlands) on day 274 of pregnancy. The surgical procedure has been extensively outlined previously [24,27]. Briefly, during abdominal surgery, two bipolar AgAgCl electrodes, made in our own laboratory with 5 mm distance in between [28], were sutured on the surface of the uterine myometrium near the top of the uterine horn.…”

“…It could be expected that these postpartum contractions of the cervix itself influence cervical diameter which could either be a decrease or an increase of the cervical diameter, as both phenomena have been described during parturition [23,24].…”

“…This paper presents the results of a study that was performed on cows that previously had been used in an experiment in which the cervical diameter and EMG activity of the myometrium and cervix were recorded during a parturition which was induced with a synthetic PGF2a analogue [24]. As a consequence of the use of PGF2a all the cows had retained placentas, due to insufficient shedding of the cotyledons from the caruncles [20], after otherwise normal calvings.…”