Expression of behavioural signs of oestrus during mid-cycle in a dairy cow

Abstract

Extract

Routine monitoring of commercial dairy herds has confirmed the occurrence of oestrus during the luteal phase of the cycle in a small proportion (<5%) of cows (Royal et al 2000). One such event occurred in one of four Friesian dairy cows being intensively monitored for progesterone and luteinising hormone (LH) concentrations in daily milk samples and 6-hourly blood samples collected from the jugular vein, throughout the postpartum period (Peters et al 1981; Fisher 1983). Consequently, the endocrine parameters associated with heat during the luteal phase were noted (Figure 1). Although an observation on a single cow, the intensive sampling data available for this animal warrant publication.