A narrative review of the challenges and opportunities for calves in pasture-based dairy systems.

Pasture-based dairy systems (pasture only and pasture plus confinement hybrids), common in countries such as New Zealand, Ireland, Australia and parts of South America, offer economic and welfare advantages by aligning calving with seasonal forage growth. However, these extensive systems present unique challenges for calf health and welfare due to exposure to adverse weather, compactness of calving and limited monitoring of disease. This narrative review synthesizes current knowledge on calf survival, morbidity, and growth in pasture-based dairy herds and identifies practical opportunities to improve outcomes. Perinatal and pre-weaning mortality remain highly variable between countries, with common risk factors including inadequate calving supervision and restricted milk feeding. The prevalence of inadequate transfer of passive immunity remains a concern in some pasture-based herds, reflecting additional gaps in colostrum management. Further, enhanced milk feeding programs, particularly higher milk allowances during early life in housed systems can improve growth and resilience, although evidence in predominantly pasture-based systems is limited. Housing improvements, including adequate space, ventilation, and hygiene, further reduce pathogen exposure and support behavioural development. For non-replacement calves, wider use of sexed semen, better pricing for dairy-beef animals, and adherence to transport-age and fitness standards can improve welfare and public perception. Continued research, benchmarking, and collaborative extension among producers, veterinarians, and industry will be essential to develop practical, evidence-based guidelines that strengthen calf health, productivity, and welfare in pasture-based dairy systems.