Stakeholder perspectives on dairy calf management challenges in North America.

Calf morbidity is common on dairies, yet stakeholders who troubleshoot these challenges possess critical experiential knowledge regarding which practices to prioritize during outbreaks. This study evaluated calf experts' perceptions of management practices most critical to address when dairies experience a high prevalence of diarrhea (>25%), bovine respiratory disease (BRD; > 15%), and umbilical infections (>5%) in calves up to 90 d of age. An online survey used a snowball sampling strategy to recruit North American calf experts (n = 70; veterinarians, extension professionals, nutritionists, and consultants) who had no financial stake in a dairy and had troubleshot calf health on ≥3 commercial farms within the past year. Respondents scored the relevance of 8 management domains from 0 to 100; domains scoring > 80 triggered "drill-down" questions where experts ranked specific management failures. Garrett scores assessed consensus within rankings, with scores > 60 indicating important factors and ≥70 indicating strong consensus. Overall, 51% (36/70) of experts reported working with farms experiencing high BRD, followed by diarrhea (47%; 33/70) and umbilical infection (13%; 9/70). For BRD, calf housing/environment had the greatest mean relevancy, followed by colostrum management and nutrition. Strong consensus emerged that restricted nutrition, specifically feeding a low quantity of milk solids (≤0.5 kg/d or ≤4 L/d), is a pivotal management failure to address during BRD outbreaks (Garrett Score = 74.75). Other critical BRD contributors included inadequate colostrum volume (≤2 L; Garrett Score = 67.94), large social groups (>10 calves; Garrett Score = 62.05), and poor winter ventilation (<4 air exchanges/h; Garrett Score = 61.60). For diarrhea, sanitation had the highest perceived relevancy, followed by colostrum, housing, and nutrition. Experts demonstrated near-consensus that large social groups (Garrett Score = 68.90) and low milk solids (Garrett Score = 68.90) exacerbate diarrhea challenges, alongside a lack of sanitation standard operating procedures (SOPs; Garrett Score = 64.36) and low colostrum volume (Garrett Score = 64.00). For umbilical infections, clear consensus linked outbreaks to a lack of umbilical cord dipping (Garrett Score = 73.60), with poor maternity pen hygiene as another contributor (Garrett Score = 68.80). These findings uniquely highlight that experts view nutritional restriction and protocol gaps as central drivers of disease severity. This study identified that dairy stakeholders such as veterinarians, extension/academics, consultants, and nutritionists believe that calf disease challenges on farm are linked to a lack of standard operating procedures for sanitation, colostrum and umbilical cord care. Moreover, underfeeding calves at ≤4 L/d milk, and housing more than 10 calves in a pen was perceived as being related to high disease pressure herds struggling with neonatal calf diarrhea and bovine respiratory disease. This suggests that future North American research should move beyond isolated risk factors to investigate how group-housing dynamics and formalization of management (such as SOP implementation) interact to influence calf disease resilience.