Adequate colostrum intake in the first hours of life is the single most important determinant of neonatal calf welfare and survival. Calves are born agammaglobulinaemic (without circulating antibodies) and depend entirely on colostral immunoglobulin absorption during the gut closure window (0-12 hours). Failure of passive transfer (FPT), defined as serum IgG below 10 g/L, affects 15-40% of calves on poorly managed farms and dramatically increases disease susceptibility and mortality. Welfare-positive colostrum management includes: feeding 3-4 litres within 2 hours of birth using an oesophageal feeder if the calf does not suckle voluntarily; testing colostrum quality with a Brix refractometer (>22% Brix indicates adequate IgG); and banking high-quality colostrum. Research demonstrates farms achieving FPT rates below 10% show 50-70% lower calf mortality. Colostrum management is increasingly incorporated into farm assurance audits as a key welfare outcome measure.