Validation of pressure measurements and electromyographic results for the uterus of cattle during the early postpartum period.
OBJECTIVE
To evaluate methods for on-farm measurements of uterine contractility in postpartum dairy cows by comparing data simultaneously recorded by use of 2 intrauterine pressure (IUP) devices and quantified electromyographic (EMG) signals.


METHODS
5 cows during the first 48 hours after parturition.


METHODS
2 EMG electrodes were implanted on the surface of the gravid uterine horn. Parturition was induced by injection of a prostaglandin F2alpha analogue at day 274 of gestation. An open-tip catheter and pressure microtransducer were transcervically inserted and affixed to a caruncle immediately after calving. Changes in IUP were recorded concurrent with EMG recordings during 2-hour periods at 2, 6, 12, 18, 24, 36, and 48 hours after parturition. Novel acquisition and analysis software programs were used with a digital data-filtering capability for evaluation of IUP and EMG signals.


RESULTS
The method for intrauterine fixation of the 2 pressure measurement instruments was effective and allowed easy, externally guided removal of the devices 48 hours after parturition. There was a high correlation between the data obtained by the 2 pressure measuring systems. Good correlation was also found between pressure data obtained by the open-tip catheter system and EMG signals. Although the quantified IUP and EMG signals were highly comparable, synchronization was not always evident during visual inspection of these signals.


CONCLUSIONS
The open-tip IUP catheter system with a special fixation method is suitable for use in on-farm studies. It will enable investigators to record natural and pharmacologically influenced uterine contractility in early postpartum dairy cows.
Bajcsy
Arpád Csaba
AC
Department of Farm Animal Health , Faculty of Veterinary Medicine, Utrecht University, 3584 CL Utrecht, Yalelaan 1-7, The Netherlands.
van der Weijden
Gijsbert C
GC
Doornenbal
Arie
A
Breeveld-Dwarkasing
Vidya N A
VN
de Jong
Rineke C
RC
Szenci
Ottó
O
Taverne
Marcel A M
MA
D000818:Animals; D002404:Catheterization / Q000379:methods / Q000662:veterinary; D002417:Cattle / Q000502:physiology*; D004576:Electromyography / Q000662:veterinary; D005260:Female; D009119:Muscle Contraction / Q000502:physiology*; D049590:Postpartum Period / Q000502:physiology*; D011312:Pressure; D014599:Uterus / Q000502:physiology*