Effect of number of cows in oestrus simultaneously on activity of dairy cows in oestrus

摘要

Poor oestrous expression is considered the main contributing factor to poor reproductive efficiency in dairycows where AI is used. Standing to be mounted is the primary sign of oestrus. However, only 50% of dairy cows arereported to show this sign (Van Eerdenburg et al., 2002). Now many dairy farms use activity monitors as an aid to oestrusdetection. One of the factors contributing to the extent of oestrous expression is the number of cows in oestrussimultaneously (Sexual Group=SG). The aim of the present study was to investigate the effect of SG on activities such asthe number of steps and lying time (h/d) during oestrus.