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 Royal, MD, Darwash, AO, Flint, APF, Webb, R, Wooliams, JA and Lamming, GE. 2000. Detecting fertility in dairy cattle: changes in traditional and endocrine parameters of fertility. Animal Science, 70: 487–501.  [Google Scholar]). 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 Peters, AR, Lamming, GE and Fisher, MW. 1981. A comparison of plasma LH concentrations in milked and suckling post-partum cows. Journal of Reproduction and Fertility, 62: 567–573.  [Google Scholar]; Fisher 1983 Fisher, MW. 1983. “The control of reproduction in the post-partum cow”. In PhD thesis, Sutton Bonington, , UK: Nottingham University.  [Google Scholar]). 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.