A RETROSPECTIVE ANALYSIS OF FACTORS CONTRIBUTING TO CALF MORTALITY AND DYSTOCIA IN BEEF-CATTLE

Records of 2191 calvings from the Clemson University Beef Physiology U nit between 1981 and 1993 were analyzed to determine factors affecting malpresentation, mortality and dystocia. Only 20 (0.91%) parturitions involved malpresentation: posterior presentation (n=14), leg deviatio ns (n=3), head deviations (n=2) and breech birth (n = 1). Dystocia aff ected calf mortality within 24 h of birth (P<0.05), with mortality inc reasing as the severity of dystocia increased. There was an overall 4. 5% death loss within 24 h of birth, with 4 and 7% mortality rates for calves from multiparous and primiparous dams, respectively (P<0.05). M ortality was higher for bull vs heifer calves (P<0.05). Ninety-four pe rcent of calvings were unassisted, while 6% were assisted births. Dyst ocia was greater (P<0.01) in primiparous (17%) than in multiparous dam s (4%). In births involving dystocia, 28.1% required mild traction, 69 .3% required heavy traction and 2.6% requited Cesarean section. Birth weights associated with normal births and mild traction (36 and 36 kg) were lighter than those associated with heavy traction and Cesarean s ection (40 and 42 kg, respectively; P<0.05). In conclusion, malpresent ations were too few to be of significance, and dystocia influenced mor tality within 24 h of birth. Calf birth weight and parity of dam expla ined most of the observed variations in dystocia. (C) 1998 by Elsevier Science Inc.