Prevalence of disorders in preweaned dairy calves from 731 dairies in Germany : a cross-sectional study
The objective of this cross-sectional study was to determine the prevalence of disorders in preweaned calves in 3 regions in Germany, exemplary for structural diversity in dairy farming. A farm visit was performed on a single occasion on 731 dairy farms in the northern, eastern, and southern regions of Germany between December 2016 and July 2019. Farms differed in herd size, geographical location, and management. In the northern region, the farms had a median of 90 milking cows and were often run as full-time family businesses, partly with external workers. The eastern region tended to have larger farms (a median of 251 milking cows), which were often large-scale agricultural enterprises with employees. In the southern region, the farms had a median of 39 milking cows and were often traditional family businesses, some of these being part-time businesses. Clinical examinations were performed on 14,164 preweaned dairy calves (median 12 calves per farm) by trained veterinarians. A complete data set was available for 13,656 calves. Almost half (42.0%) of the evaluated calves were classified as being affected by at least 1 of the common calf disorders. Omphalitis (O, 20.9%; n = 2,876) and diarrhea (D, 18.5%; n = 2,670) were the most frequently recorded diagnoses, whereas respiratory diseases (RD) were observed to a lesser extent (8.7%; n = 1,100). A striking feature was the fact that 7.1% (n = 987) of the calves were affected by more than 1 disorder at the same time (multimorbidity, M). The following combinations of disorders were frequently observed: O and D (n = 596), O and RD (n = 164), and D and RD (n = 140). Disorders such as O and D, as well as M, were predominantly observed in calves aged 2 wk. A gradual increase in the frequency of RD was observed with age. For all disorders except RD, male calves were more often affected than females. Omphalitis was predominantly diagnosed in the summer months, whereas RD, D, and M were more common in the fall. We detected several statistically significant differences in the prevalence of clinical signs and disorders in preweaned dairy calves between the 3 exemplary regions. The prevalence of RD was higher in the south (10.8%) than in the north (8.2%) and east (7.4%). In the north (33.2%), O was observed more frequently than in the other regions (east: 18.9%; south: 10.5%), whereas D was found less frequently in the north (13.8%) than in the east (21.6%) and south (20.0%).