Table 1 Variables tested in the univariable analyses for associations with clinical mastitis and high milk somatic cell counts in a random sample of Swiss dairy farms with >10 cows

Demographic data

Farmers age, agricultural education, continuous agricultural training, language, farming as the main source of income

Farm characteristics

Agricultural zone, average milk production per cow in 2010, organic farming, affiliation to federal incentive programs

Farm management

Dairy cow replacement system, measures before purchasing a dairy cow, dairy cattle that spend the summer in alpine pastures, vaccination, parasite prophylactic measures, homeopathic treatments, herbal medicine treatments, claw trimming frequency

Stall characteristics

Type of stall, cow trainer†, type of flooring‡, flooring material‡, lying system‡, lying surface, bedding substrates, lying surface cleaning, feeding trough cleaning, drinking trough cleaning

Milking practices

Milking system, somatic cell count controls frequency, milk samples for bacteriological analysis taken from cows with clinical or subclinical mastitis

Drying off practices

Cessation of milking, milk samples for bacteriological analysis taken at drying off, California Mastitis Test (CMT) carried out at drying off, dry cow antibiotic treatments, dry cow internal teat sealant application, dry cow udder controls

Hygiene measures taken at milking

Hand washing before milking, clean clothing, apron, rubber gloves, hands cleaned during milking, no special measure, fore-milking, teat cleaning, teat cleaning material, fresh teat cleaning material used after each cow, post milking teat disinfection, cows are prevented from lying down after milking, strategy for milking CMT positive cows, teat cup liner material, teat cup liners changing frequency

Feeding practices

Written feeding plan, feed analysis carried out, type of feed ration for dairy cows, transit feed given before calving, body condition of dairy cows at calving in comparison with drying off, body condition score is monitored, number of concentrate intakes per day at the beginning of the lactation

Peripartum measures

Calving pen available, clean bedding material, calving environment is cleaned and disinfected, intervention at calving is normally avoided, hands and arms are cleaned if intervention is required, tail/vulva and surroundings are cleaned, mechanical obstetricians available, ropes or chains available, no special peripartum measure

Genetic selection

Most important characteristics when selecting a bull for artificial insemination