Newborn calves are routinely separated from their dams within 24 h of birth. This approach has traditionally been thought to reduce separation stress of the cow-calf pair, as well as improve health of the calf. However, early cow-calf separation is scrutinized as an approach that may reduce animal welfare and well-being of cow and calf. Moreover, calf disease risk and mortality remain stagnant at unacceptably high levels. Our central hypothesis is that prolonged direct cow-calf social contact improves calf behavior, affective state, growth, immune response and the ability to establish a robust and diverse gastrointestinal and respiratory microbiome that increase host resilience. We further hypothesize that early vs. delayed separation of the calf affects the behavior and well-being as well as udder health and milkability of the postpartum cow. We address this in four distinct objectives: the effects of early vs. delayed cow-calf separation on (1) cow and calf behavior and affective state, (2) calf health, growth and immune response, (3) the dam´s udder health, milkability and milk production, and (4) on the calf gut and respiratory microbiome and the dam´s udder microbiome. Our PARTNERSHIP proposal aligns with the Welfare and Well-being of Agricultural Animals (A1251) Program Area Priority. We apply the evaluation of a current and widespread animal agriculture production practice and development of enhanced management approaches to safeguard animal welfare and sustainable production. Our goal is to provide scientific evidence to inform industry best practices based on all relevant outcomes measured in this multi-pronged collaborative approach.