Co-Authors:
Amir, D., Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Rosenberg, M., Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Schindler, H., Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Abstract:
The seasonal and post partum oestrus occurrence and ovarian activity, assessed by the plasma progesterone concentrations, were studied in Finn-cross ewes following autumn and winter lambings. The last seasonal oestrous cycle was followed by a silent ovulation in C0% of the Finn x Awassi ewes. Silent ovulations during midanoestrus occurred in 50% of the ewes, and in 90% of the animals a silent ovulation preceded the normal resumption of the seasonal sexual activity. The first post partum oestrus occurred within CO days after October lambings in about 90% of the ewes. Silent ovulations before the first post partum oestrus were evident in 70% of the recycling ewes. It is suggested that breeding ewes with ovarian activity after oestrus induction during anoestrous periods might increase the reproductive performance of the flock in a frequent lambing system. © 1984, Cambridge University Press. All rights reserved.