Abstract
A series of experiments is reported in which the effect on the length of heat of varying degrees of association of the sexes was studied in Merino sheep. Length of heat in all ewes was determined by teasing with vasectomized rams at 4-hr intervals. When present throughout oestrus, mating behaviour of rams and also of stilboestrol-treated (`masculinized') ewes, reduced heat length in experimental ewes by some 30 to 50%. The sight, smell and sound of the rams were not sufficient to reduce the duration of oestrus. However, neither mounting nor intromission were necessary components of the male behaviour for the effect to be fully expressed. Oestrous periods synchronized by injections of progesterone were as effectively shortened by the continuous presence of the rams. The ewes were most sensitive to the effect of ram activity between 4 and 8 hr after the beginning ofoestrus, but oxytocin treatment during this time did not reduce oestrous duration.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
