BackgroundProphylactic measures are key components of dairy herd mastitis control programs, but some are only relevant in specific housing systems. To assess the association between management practices and mastitis incidence, data collected in 2011 by a survey among 979 randomly selected Swiss dairy farms, and information from the regular test day recordings from 680 of these farms was analyzed.ResultsThe median incidence of farmer-reported clinical mastitis (ICM) was 11.6 (mean 14.7) cases per 100 cows per year. The median annual proportion of milk samples with a composite somatic cell count (PSCC) above 200,000 cells/ml was 16.1 (mean 17.3) %. A multivariable negative binomial regression model was fitted for each of the mastitis indicators for farms with tie-stall and free-stall housing systems separately to study the effect of other (than housing system) management practices on the ICM and PSCC events (above 200,000 cells/ml). The results differed substantially by housing system and outcome. In tie-stall systems, clinical mastitis incidence was mainly affected by region (mountainous production zone; incidence rate ratio (IRR) = 0.73), the dairy herd replacement system (1.27) and farmers age (0.81). The proportion of high SCC was mainly associated with dry cow udder controls (IRR = 0.67), clean bedding material at calving (IRR = 1.72), using total merit values to select bulls (IRR = 1.57) and body condition scoring (IRR = 0.74). In free-stall systems, the IRR for clinical mastitis was mainly associated with stall climate/temperature (IRR = 1.65), comfort mats as resting surface (IRR = 0.75) and when no feed analysis was carried out (IRR = 1.18). The proportion of high SSC was only associated with hand and arm cleaning after calving (IRR = 0.81) and beef producing value to select bulls (IRR = 0.66).ConclusionsThere were substantial differences in identified risk factors in the four models. Some of the factors were in agreement with the reported literature while others were not. This highlights the multifactorial nature of the disease and the differences in the risks for both mastitis manifestations. Attempting to understand these multifactorial associations for mastitis within larger management groups continues to play an important role in mastitis control programs.

Health prophylaxis management practices have acquired a major role in the success of dairy herd health programs, however, little is known about the scope and level of implementation on Swiss dairy farms. The main objective of this study was therefore to provide a general overview of the most important preventive measures which are currently being used on these farms. In March 2011, an online survey with 75 questions was sent to 2'285 randomly selected Swiss dairy farmers. Response rate by question ranged from 35 to 53 %. Within this study, answers were compared between dairy farms with a tie-stall (n = 739) and farms with a free-stall (n = 458). Homeopathic treatments were used by 51 % of the dairy farmers and antibiotic dry cow treatments by 94 %. Farmers with a tie-stall tended to carry out more prophylactic treatments against external parasites, vaccinated their cows more frequently against Clostridium chauvoei and Moraxella bovis, and carried out claw trimming more frequently than dairy farmers with a free-stall. A higher proportion of dairy farmers with a free-stall had a written feeding plan, carried out regular feed analysis, wore an apron and rubber gloves during milking, and carried out post milking teat disinfection more frequently than dairy farmers with a tie-stall. The data collected in this survey could assist in improving future dairy health communication campaigns in Switzerland.

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