Absence of a causal relationship between environmental and body temperature in dairy cows (Bos taurus) under moderate climatic conditions
(1). Continuous body temperature records from dairy cows for 46 days of summer and contemporary data for climate temperature humidity index (THI) were analysed. (2). A large component of the body temperature data was not explained by changes in THI. (3). Outside a normal range of values (above 72 for THI and 39.05 °C for body temperature), there was evidence of a causal relationship with a time delay of about 120 minutes. (4). Both variables had a prominent circadian component, but these were more likely to be due to common and/or independent causes than to any direct relationship.
Keywordsdevelopment; circadian rhythm; core temperature; dairy cows; heat stress; climate; temperature rhythm; Physiology
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