The transition period — three weeks before to three weeks after calving — is the highest-risk period in the dairy cow productive cycle. Metabolic disease, immune suppression, and welfare challenges concentrate in this window.
The transition period is the welfare crucible of dairy farming: the weeks around calving concentrate the most significant health challenges a dairy cow faces across her productive life. The hormonal shifts of late pregnancy and early lactation cause profound metabolic changes — rapid mobilization of fat reserves to fuel milk production, calcium redistribution from bone to milk, immune system reorganization — that create vulnerabilities to diseases that cause significant suffering when they occur. Milk fever causes collapse and inability to rise; ketosis causes neurological changes and appetite suppression; metritis causes fever and systemic illness; displaced abomasum causes chronic pain and reduced intake. Each of these conditions is partially preventable through targeted management intervention, and when they do occur, early detection and treatment significantly reduces welfare harm and productivity loss. The welfare investment in transition cow management — appropriate dry cow body condition management, comfortable transition housing with adequate space, systematic monitoring protocols, and proactive supplementation — has among the highest welfare and economic returns per unit of investment of any farm management decision.