Quantifying the impact of frequent diseases and syndromes on calf health using the opinions of producers and veterinarians: Towards dairy calf disability weights.

The first objective of this study was to quantify the impact and disability weight (DW) of frequent diseases or syndromes of pre-weaned dairy calves using the perceptions of producers and veterinarians. The second objective was to compare the opinions of producers and veterinarians regarding the impact and DW of dairy calves' frequent diseases and syndromes. A survey was conducted to obtain demographic information and opinions of 39 dairy producers and 52 veterinarians on the impact of frequent disease and syndromes on calf health. Most of the producers (97.4%, 38/39) were clients of the ambulatory clinic at the Faculté de médecine vétérinaire de l'Université de Montréal (FMV, UdeM) in Saint-Hyacinthe, Québec, Canada. They were actively engaged in calf research projects. Québec veterinarians were contacted via email through their association. Additionally, veterinarians from the bovine ambulatory clinic and the bovine veterinary hospital at the FMV, UdeM, were contacted directly via email. A visual analog scale, represented by a horizontal line ranging from 0 (no impact) to 10 (maximum impact (i.e., death or euthanasia)), was used to estimate the impact of 9 frequent diseases or syndromes (diarrhea, dystocia, inadequate transfer of passive immunity, fracture, wound or abscess, arthritis, respiratory disease, umbilical infection, and congenital defect) on calf health following previously reported methods (using the most probable, and range of the perceived impact for each participant and disease). The DW values were obtained by converting the impact values to a probability density in a scale from 0 to 1 using betaPERT method. Average impacts and DW were quantified for each frequent disease and syndrome. Average impact differed statistically across different diseases and syndromes. The highest average impacts were obtained for the presence of a fracture (6.49/10), arthritis (6.22/10), and congenital defects (6.03/10), while the lowest impact was observed for the presence of a wound or abscess (3.42/10). The opinions of producers and veterinarians were similar for most of the selected diseases and syndromes; however, statistical differences were observed for arthritis (producers = 5.13 vs veterinarians = 6.88), umbilical infection (producers = 3.65 vs veterinarians = 4.74), and dystocia (producers = 3.87 vs veterinarians = 4.58). A strong correlation coefficient (0.72) was observed between the observed ranks of diseases and syndromes of producers and veterinarians. In conclusion, we quantified how frequent diseases and syndromes affect calf health. Producers and veterinarians mostly agreed on their impact. Estimating DW is a crucial first step in creating a health measure for dairy calves. Similar to humans, this metric will be important for health comparative analysis for producers, veterinarians, and industry.