Parturition and Dystocia

Dystocia, (difficult birth), occurs when the first or second stage of labor is prolonged and assistance is required for delivery. No clear boundaries exist between dystocia and eutocia, (normal birth), but guidelines based on progress and duration of the delivery may aid the veterinarian and producer in deciding when to interfere with the birth process. In the last century a lot of improvement has occurred in the techniques used to deliver and resuscitate calves. However it is only in the last three decades that research has been effectively directed toward the causes and management of dystocia. This may be associated with the more widespread implementation of herd health programs and the use of computers to facilitate data management. The incidence of dystocia varies but is generally more common among first-calf heifers, because they have not yet reached their mature size, and then decreases with age.1 Death due to dystocia or as a result of injuries sustained during delivery is the most common cause of calf loss during the first 96 hours postpartum, with most losses occurring during the first 24 hours after delivery.2,3 The subsequent pregnancy rate of dams that suffer dystocia is also reduced.4-6 While it is not possible to eliminate dystocia, improvements in management of heifers during their development and observation of cows and heifers during the calving season are critical for reducing calf losses.This chapter initially describes the process of normal parturition (eutocia) followed by a description of the diagnosis and treatment of dystocia. Finally, due to the importance of dystocia control and prevention, management techniques used to reduce the incidence of dystocia are discussed, with the main focus being on specific control measures.