Incidence of uterine torsion during veterinary-assisted dystocia and singleton live births after vaginal delivery in Holstein-Friesian cows at pasture

ObjectiveTo determine the incidence of uterine torsion and their association with live births after vaginal delivery at pasture.MethodsA total of 119 veterinary-assisted dystocia, occurred in Holstein-Friesian cows, were accessed between September 2012 and February 2013 from Azores islands (Portugal). The general health status of dam, cause of dystocia, obstetric treatment choice, number and viability of fetus were evaluated.ResultsThe uterine torsion represented 24.4% (29/119) of total assisted dystocia. The general health status was normal or slowly affected, at delivery time, for 96.6% (28/29) of the cows with uterine torsion. Vaginal delivery after rolling cows, cesarean section or euthanasia were performed in 72.4% (21/29), 24.1% (7/29) and 3.5% (1/29) of dams with uterine torsion, respectively. Singletons were observed in 96.6% (28/29) and 86.7% (78/90) of cows with uterine torsion and remaining dystocia, respectively. After vaginal delivery, the occurrence of singleton live births was more probable to occur in cows with uterine torsion (17/21) than the remaining cows (37/70) of control group (odds ratio = 3.79; 95% interval of confidence from 1.16 to 12.41; P < 0.05).ConclusionsA high frequency of uterine torsion was observed in Holstein-Friesian cows with normal or slowly affected general health status at delivery time at pasture. The singleton live births prevailed and, in general, their occurrence by vaginal delivery after uterus reposition were most likely to occur in cows with uterine torsion than dams presenting other dystocia.