Heat-Related Mortality In Dairy Cattle: A Case Crossover Study
This study investigated the relationship between mortality and stressful weather to specifically quantify the correlation between heat and mortality within a large sample of dairy cows in three districts in Italy.
This study of 6,697 adult Italian dairy cows that died during the summer months from 2002-2006 in three Italian districts found that exposure over the temperature-humidity index (THI) cut-off increased the risk of mortality by 1.6 times. A 4% increase in mortality was noted for each degree of THI increase above the threshold. This increase in dairy cow mortality should be considered when adopting farmed animal welfare management and transport procedures.