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Two comparative studies were undertaken using adult, female red and Père David's deer to examine the ovulatory response of these animals to a superovulation regimen and fertilization rates following inter- and intraspecific laparoscopic insemination. In Expt 1 six Père David's deer and 12 red deer hinds were treated during the breeding season with an intravaginal progesterone-impregnated controlled internal drug release device (CIDR) for 14 days, with 200 iu pregnant mares' serum gonadotrophin (PMSG) administered 72 h before the device was withdrawn and eight injections of ovine FSH given at 12 h intervals starting at the time of PMSG administration. Oestrous behaviour began one day after CIDR device withdrawal (Père David's deer: 24.00 +/- 2.32 h; red deer: 24.60 +/- 2.23 h). The duration of oestrus was greater in Père David's deer than in red deer (17.50 +/- 1.43 h and 8.25 +/- 3.25 h, respectively, P < 0.001). The peak LH surge of Père David's deer was 68.65 +/- 4.74 ng ml-1 occurring 29.00 +/- 2.41 h after removal of the CIDR devices. In comparison, the peak LH surge in red deer was 17.09 +/- 3.64 ng ml-1 (P < 0.001), occurring 24.00 +/- 0.00 h after CIDR device withdrawal. Pre-surge concentrations of LH were also greater (P < 0.001) in Père David's deer (1.37 +/- 0.11 ng ml-1) than in red deer hinds (0.41 +/- 0.02 ng ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

The oestrous cycles of fourteen red deer hinds (six yearling; eight more than 2 years old) were synchronized during the early breeding season by removal of a progesterone-containing intravaginal device and blood samples were taken at intervals of 3 h commencing 13 or 25 h later and continued for 54 h. The controlled internal drug release devices (CIDRs) were removed at 08:00 h (group 1; three yearlings and four adults) or 12 h later at 20:00 h (group 2; three yearlings and four adults). There was no significant effect of time of removal of CIDR on the interval to the onset of oestrus (group 1, 34.5 +/- 4.05 h; group 2, 42.14 +/- 7.8 h) on the time of peak concentration (group 1, 41.81 +/- 5.69 h; group 2, 41.71 +/- 7.81 h) or on duration of the luteinizing hormone (LH) surge (group 1, 15.00 +/- 0.95 h; group 2, 14.57 +/- 0.78 h). The six yearling animals exhibited oestrus and LH surge significantly later than the adults (55 +/- 4.2 versus 32 +/- 6.3 h for the LH surge for yearling and adult females, respectively). In a further experiment, 20 hinds were synchronized during the breeding season by removal of CIDR at two times of day 12 h apart and placed with a stag. Mating took place at a mean time of 42.1 +/- 2.4 h and 37.0 +/- 1.3 h later in the two groups. There was no significant effect of time of removal of CIDR upon time to onset of oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)