Risk Factors and Economic Impact of Dystocia in Dairy Cows: A Systematic Review

Absract: Reproductive health problems are one of the most important problems that affect the production and productivity of dairy cows. Dystocia is also one of the reproductive health problems that cause considerable economic loss to the dairy industry. The main aims of this manuscript were to review risk factors and economic impact of dystocia in dairy cows. Dystocia is also defined as prolonged or difficult parturition and it is a condition in which the first or, especially the second stage of parturition was markedly prolonged for more than 6 hr and the cow required assistance. There are different causes and risk factors associated with dystocia in dairy cattle which can result from both maternal and foetal factors. Breed parity, weight and condition of cow at calving, sex and birth weight of calf, malpresentation, multiple calving can be a risk factors for dystocia. Foeto-pelvic incompatibility is the major reason leading to difficulty at calving. However, dystocia can result from other causes that interfere with the expulsive forces needed to expel the calf. This includes: lack of uterine contractions (weak labour), incomplete dilation of the cervix and vagina due to stenosis and uterine torsion. Dystocia has negative impacts on the farm, the cow and the calf. It is an undesirable reproductive event resulting in increased risk of calf morbidity and mortality, reduced fertility and milk production, as well as cow survival and consequently reduces farm profitability on dairy farms. Moreover, dystocia may have negative effects on reproductive performance, causing stillbirth, cow death, retained placenta, uterine infections, or increased involuntary culling, which have negative consequences for farm economics as well as for cow welfare. Thus to avoid its adverse effect every dairy should implement a dystocia monitoring program and employ management practices that limit the occurrence and impact of dystocia.