[Effect of stress on uterine contraction in cows]

The investigation was carried out to observe the influence of stress upon the motility of the uterus from 1st to 5th day after parturition or cesarotomy. The experiments involved 24 lowland black and white cows; in 12 of them cesarean section was performed. The motility of the uterus was recorded with the balloon method by way of air transmission. The starting uterine contractions curve having been recorded, for 15-20 minutes one of following stress agents was applied: taking the calf away, change of stall, putting under restraint, collecting small amounts of blood or milking by a strange person. Besides, 2 ml 0.1% adrenaline solution or 4 I.U. oxytocin was administered intravenously. Adrenaline was administered before or after oxytocin, or both the hormones were applied together. Oxytocin was also applied during the stress. During the action of the stress as well as after administration of adrenaline there was observed complete decay of uterine contractions from 1st to 5th day after parturition or cesarotomy. No changes in the motility of the uterus were brought about by intravenously administration of oxytocin during the stress. No response of the uterus to oxytocin was observed, either, when adrenaline had been administered before. Both exogenic and endogenic adrenaline was found to restrain strongly the contractions of the examined organ, or to decay them completely, which has a negative effect upon involution of the uterus in cows in the first days after parturition.