[The effect of environmental factors on the occurrence of udder diseases].

The influence of housing factors on udder diseases was investigated in 2156 tiestall barns with 41893 cows and in 98 loose housed herds with 4126 cows. In loose housed herds less teat injuries were observed and also less mastitis than in tiestall barns. Within the different tiestall systems there was a trend to more udder diseases in short standings with a dung grid than in other systems. The ordinary neck chain and the "Grabner"-tethering system showed better results than the horizontal chain and the yoke tying system. Stall partitions between the cows caused a marked reduction of udder diseases. The installation of a cow trainer showed advantages regarding udder diseases. Inaccurate standing measurements (length and width) caused more udder diseases. When the metal grid was in poor condition, the incidence of teat injuries as well as udder diseases of heifers increased. Teat injuries and udder infections were more frequent when limb or digit injuries were found. Regular hoof care twice a year reduced the udder disease rate. Bedding material influenced the incidence of udder diseases positively. On farms where the cows were on pasture, the incidence of udder infections was higher than on farms where the cows were permanently housed. Heifers that were tied as calves or as juveniles showed significantly less udder diseases than those that were raised in groups. Faults in milking, defects in milking machines and deficits in milking hygiene showed a negative effect on udder diseases.