Calving in double muscled cows: why cows do not strain abdominally during parturition and prediction of parturition.

Abstract

In this pilot study we looked at the parturition of 14 double mouscled ‘verbeterd roodbont’ cattle on a commercial farm in the Netherlands. Before parturition we reviewed several clinical and behavioral parameters to predict the exact time of parturition (1) since this proves to be a difficult matter for a lot of farmers. During parturition we attempted to find a cause for the lack of abdominal strain that some animals tended to show when in partu (2) despite the fact that they should be able to deliver naturally according to size of the calf and size of the pelvis.

1: Cows were monitored every 12 hours before parturition until 12 hours before expected calving, based on prodromiafter which they were monitored every 4 hours . Rectal temperature showed a drop 24-36 hours before calving and keeping the tail away from the body proved to be a useful parameters for upcoming parturition in 1-6 hours as well, also relaxation of the sacrosciatic ligaments, swelling of the udder and restless behaviour showed some relation (however not significant) with the onset of parturition.

2: The hypothesis of the high birthweight of the calves causing a late onset of straining could neither be rejected nor confirmed. Only one cow was able to calve per vaginam, most calves were delivered by Cesaerean Section. However, cows were able to strain abdominally on the appearance of the amniotic sac indicating that breeders did not unintentionally select on ‘non straining’ animals. Also the number one cause for lack of abdominal straining in dairy cattle, milk fever, could be ruled out since none of the cows had low calcium levels within one hour after calving. To confirm the hypothesis’ in this study further research is needed with more cows and a higher proportion of cows that are able to calve naturally.