Detection of silent oestrus in dairy cows by milk temperature measurement

Abstract

AbstractMilk temperature was measured automatically during milking with a view to detecting silent oestrus in dairy cows. A total of 38 silent oestrous periods were studied, based mainly on ovulation and milk progesterone levels together with visual observation.In 78·9% of silent oestrous periods, a significant increase in milk temperature amounting to a mean of 0·6 (s.e. 0·07)°C was found, and this was highly correlated (r = 0·90) with an increased body temperature. In most silent oestrous periods increases in milk and body temperatures and ovulation with milk progesterone levels below 2 μg/l were found, the oestrous cycles being characterized by typical progesterone profiles. In some cows increases in milk and body temperatures and ovulation during a silent oestrous period were associated with non-typical progesterone profiles although most of these occurred shortly after parturition.