Response of anoestrous ewes pre-treated with a single dose of oestradiol-17β, or progesterone and oestradiol-17β, to the introduction of rams and ewes in oestrus

References

• Bartlewski , PM , Beard , AP , Cook , SJ and Rawlings , NC . 1998 . Ovarian follicular dynamics during anestrus in ewes . Journal of Reproduction and Fertility , 113 : 275 – 85 .
   PubMedGoogle Scholar
• Bo , GA , Baruselli , Ps , Moreno , D , Cutaia , L , Caccia , M , Tribulo , R , Tribulo , H and Mapletoft , RJ . 2002 . The control of follicular wave development for self-appointed embryo transfer programs in cattle . Theriogenology , 57 : 53 – 72 .
   PubMed Web of Science ®Google Scholar
• Caraty , A , Locatelli , A and Martin , GB . 1989 . Biphasic response in the secretion of gonadotrophin-releasing hormone in ovariectomized ewes injected with oestradiol . Journal of Endocrinology , 123 : 375 – 82 .
   PubMed Web of Science ®Google Scholar
• Ginther , OJ , Kot , K and Wiltbank , MC . 1995 . Associations between emergence of follicular waves and fl uctuations in FSH concentrations during the estrous cycle in ewes . Theriogenology , 43 : 689 – 703 .
   PubMed Web of Science ®Google Scholar
• Hunter , GL , Belonje , PC and Van Niekerk , CH . 1971 . Synchronized mating and lambing in spring-bred Merino sheep: the use of progestogen-impregnated intra-vaginal sponges and teaser rams . Agroanimalia , 3 : 133 – 40 .
   Google Scholar
• Martin , GB . 1979 . Ram-induced ovulation in seasonally anovular Merino ewes: effect of oestradiol on the frequency of ovulation, oestrus and short cycles . Theriogenology , 12 : 283 – 7 .
   Google Scholar
• Martin , GB , Oldham , CM , Cognié , Y and Pearce , DT . 1986 . The physiological responses of anovulatory ewes to the introduction of rams — a review . Livestock Production Science , 15 : 219 – 47 .
   Google Scholar
• Meikle , A , Forsberg , M , Garófalo , EG , Carlsson , MA , Lundeheim , N and Rubianes , E . 2001 . Circulating gonadotrophins and follicular dynamics in anestrous ewes after treatment with estradiol-17β . Animal Reproduction Science , 67 : 79 – 90 .
   PubMed Web of Science ®Google Scholar
• Pearce , DT , Oldham , CM , Haresign , W and Gray , SJ . 1987 . Effects of duration and timing of progesterone priming on the incidence of corpora lutea with a normal lifespan in Merino ewes induced to ovulate by the introduction of rams . Animal Reproduction Science , 13 : 81 – 9 .
   Google Scholar
• Rodríguez Iglesias , RM , Ciccioli , N , Irazoqui , H and Rodríguez , BT . 1991 . Importance of behavioural stimuli in ram-induced ovulation in seasonally anovular Corriedale ewes . Applied Animal Behavior Science , 30 : 323 – 32 .
   Google Scholar
• Rubianes , E , de Castro , T and Carbajal , B . 1996 . Effect of high progesterone levels during the growing phase of dominant follicle of wave 1 in ultrasonic-monitored ewes . Canadian Journal of Animal Science , 76 : 473 – 5 .
   Google Scholar
• Rubianes , E , Beard , A , Dierschke , DJ , Bartlewski , P , Adams , GP and Rawlings , NC . 1997 a . Endocrine and ultrasound evaluation of the response to PGF 2 alpha and GnRH given at different stages of the luteal phase in cyclic ewes . Theriogenology , 48 : 1093 – 104 .
   PubMed Web of Science ®Google Scholar
• Rubianes , E , de Castro , T , Ungerfeld , R , Meikle , A and Rivero , A . 1997 b . Ovarian response after a GnRH challenge in seasonally anestrous ewes . Canadian Journal of Animal Science , 77 : 727 – 30 .
   Google Scholar
• Smith , JF , McGowan , LT , Dobbie , JL and Smart , SH . 1989 . Seasonal pattern of ovulation in Merino, Romney and Merino x Romney ewes . Proceedings of the New Zealand Society of Animal Production , 49 : 249 – 54 .
   Google Scholar
• Souza , CJH , Campbell , BK and Baird , DT . 1996 . Follicular dynamics and ovarian steroid secretion in sheep during anoestrus . Journal of Reproduction and Fertility , 108 : 101 – 6 .
   PubMedGoogle Scholar
• Ungerfeld , R . 2007 . Reproduction in Domestic Ruminants VI , Edited by: Juengel , JI , Murray , JF and Smith , MF . 207 – 21 . Nottingham, , UK : Nottingham University Press . In
   Google Scholar
• Ungerfeld , R and Rubianes , E . 1999 . Effectiveness of short-term progestogen primings for the induction of fertile oestrus with eCG in ewes during late seasonal anoestrus . Animal Science , 68 : 349 – 53 .
   Google Scholar
• Ungerfeld , R , Pinczak , A , Forsberg , M and Rubianes , E . 2002 . Ovarian responses of anestrous ewes to the “ram effect” . Canadian Journal of Animal Science , 82 : 599 – 602 .
   Google Scholar
• Ungerfeld , R , Suárez , G , Carbajal , B , Silva , L , Laca , M , Forsberg , M and Rubianes , E. 2003 . Medroxyprogesterone primings and response to the ram effect in Corriedalea ewes during the non-breeding season . Theriogenology , 60 : 35 – 45 .
   PubMed Web of Science ®Google Scholar
• Ungerfeld , R , Dago , AL , Rubianes , E and Forsberg , M . 2004 a . Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17 beta . Reproduction, Nutrition, Development , 44 : 89 – 98 .
   PubMedGoogle Scholar
• Ungerfeld , R , Forsberg , M and Rubianes , E . 2004 b . Overview of the response of anoestrous ewes to the ram effect . Reproduction, Fertility, and Development , 16 : 479 – 90 .
   PubMed Web of Science ®Google Scholar
• Viñoles , C , Forsberg , M , Banchero , G and Rubianes , E . 2001 . Effect of long-term and short-term progestagen treatment on follicular development and pregnancy rate in cyclic ewes . Theriogenology , 55 : 993 – 1004 .
   PubMed Web of Science ®Google Scholar