Invited review: The influence of immune activation on transition cow health and performance—A critical evaluation of traditional dogmas

The progression from gestation into lactation represents the transition period, and it is accompanied by marked physiological, metabolic, inflammatory adjustments. entire a cow's opportunity to have an additional are heavily dependent on how successfully she adapts during periparturient period. Additionally, disproportionate amount of health care culling occurs early following parturition. Thus, maladaptation has been researched area dairy science for more than 50 yr. It was traditionally thought that excessive adipose tissue mobilization in large part dictated period success. Further, magnitude hypocalcemia also assumed partly control whether cow effectively navigates first few months lactation. canon became released nonesterified fatty acids (NEFA) resulting hepatic-derived ketones coupled with lead immune suppression, which responsible disorders (e.g., mastitis, metritis, retained placenta, poor fertility). In other words, dogma evolved these metabolites were causal problems efforts should be enlisted prevent increased NEFA, hyperketonemia, subclinical hypocalcemia. However, despite intensive academic industry focus, remains hurdle animal welfare, farm profitability, sustainability. stands reason there alternative explanations failures. Recently, become firmly established activation ipso facto response normal component biology. origin likely stems mammary gland, trauma parturition, gastrointestinal tract. If inflammation becomes pathological, reduces feed intake causes Our tenet system utilization glucose its induction hypophagia extensive increase NEFA ketones, this explains why they (and severity hypocalcemia) correlated health, production, reproduction outcomes. review, we argue changes circulating calcium simply reflective either (1) homeorhetic adjustments healthy, high-producing cows use prioritize milk synthesis or (2) consequence sequelae.