| dc.description.abstract | This thesis focuses on the prevalence of dystocia due to “foetal malpresentation” in that this term is used to encompass abnormalities in foetal presentation, position and posture. It is an undesirable event for the dairy or beef farmer when the expulsion of a calf is obstructed endangering both mother and calf. The normal presentation of the calf is longitudinal anterior or posterior in a dorsal upright position with all body parts extended in the birth canal for parturition, any other position is considered as a malpresentation. The various types of malpresentations are for example deviation of the head, carpal flexion and hock flexion. Data was recorded and analyzed from Dairystream farm of over 300 Holstein Friesian cows and compared with reviewing studies conducted by various authors on the prevalence of malpresentations. Factors contributing to the prevalence of malpresentation are: the year, breed of sire used, breeding effects as in crossbred, purebred and local breeds of cows, effects of increasing foetal numbers i.e. twins and their distribution between the left and right uterine horns. Examining the physiology of malpresentation does not seem to be fully understood. Nevertheless, around the seventh month of gestation the presentation is either anterior or posterior and the reversal should not happen as the length of the foetus is longer than the diameter of the amnion. Malpresentations need to be minimized to improve reproductive performance and maximize profits as it is one of the most common causes of dystocia. There is also economic importance of reducing the amount of malpresentations in terms of calf losses, veterinary costs, treatment, prevention and subsequent impaired reproductive performance. | en_US |
