The transition period in dairy cows is defined as the last three weeks before parturition to three weeks after parturition, characterized by tremendous metabolic and endocrine adjustments that the cows must experience from late gestation to early lactation. Perhaps the most important physiological change occurring during this period is the decrease in dry matter intake around parturition and the sudden increase in nutrients that cows need for milk production. As a result remarkable changes, most of the infectious diseases and metabolic disorders occur during this time period like milk fever, ketosis, retained fetal membranes (RFM), metritis and displacement of the abomasum (DA) primarily affect cows within the first two weeks of lactation. Physical and metabolic stresses of pregnancy, calving and lactation contribute to the decrease in host resistance during the periparturient period. During two weeks before and after parturition the T-cells populations exhibit a significant decline, which contribute to the immune-suppression in dairy cows at calving leads to increased susceptibility to mastitis and other infectious diseases. Other diseases that are not clinically apparent during the first two weeks of lactation (laminitis, ovarian cysts, endometritis) can be traced back to insults that occurred during early lactation. Feeding and other Managemental strategies during transition period determines the cows productivity during the preceding lactation period. Providing the right nutrition during this period greatly improve the calving ease, cow and calf welfare, milk production and reproductive performance. Careful attention to minimize the depth and length of negative energy and protein balance are equally as important as the provision of adequate calcium, magnesium and phosphorus. Apart from the nutritional aspects, housing is also very important for effective management of transition cows especially to reduce the incidence of the probable complications arising out of metabolic disturbances.
Keywords: Down-calver; Endocrine; Ketosis; Laminitis; Metritis; Transition.
Review Article
P. 31-37