Does the weather influence the occurrence of abomasal displacement in dairy cows?
Aim of the study was to investigate the correlation between the occurrence of abomasal displacement and the weather situations. Data were collected for the years 2000 and 2001 in the area around Lisbon at 26 farms keeping about 6500 Holstein-Friesian milk cows; the analysis of 372 cases of abomasal displacement were included in the study. The weather situation was assessed on daily basis: atmospheric pressure, relative humidity, precipitation, daily insolation, maximum air temperature, minimum air temperature and average wind velocity. These original parameters were modified for the statistical analyses according to atmospheric pressure, water vapour pressure, relative humidity, temperature, temperature range, precipitation, insolation and wind speed. The change of the weather situation was described by the mean absolute deviation (deviation of the meteorological parameters from the running mean over a period of 5 and 10 days) and by a method which was based on the principal component
