Characterisation of socio-sexual interactions that affect reproduction in sheep: male novelty, sexual segregation and neural pathways

[Truncated abstract] In anovulatory ewes, exposure to rams increases the secretion of luteinising hormone (LH) and can lead to an LH surge and thus ovulation (the 'male effect'). Likewise, there is a 'female effect' in rams in which exposure to ewes stimulates the secretion of LH and testosterone, increases sexual behaviour and probably the male socio-sexual signals. These interactions between the sexes reinforce each other, enhancing the outcome with respect to induction of ovulation. The objective of this thesis was to address five major gaps in knowledge that impede advancement of our understanding of the phenomenon and its commercial application. First, we tested whether the 'familiarity/novelty' of the rams affects their ability to evoke an LH response in ewes. Ewes maintained with rams become habituated and unresponsive to male socio-sexual signals but can become receptive again after a period of sexual segregation.