Artificial insemination, hybridization and pregnancy detection in sika deer (Cervus nippon )

Artificial insemination (AI) was performed on sika hinds (Cervus nippon ) receiving various dosages of pregnant mare serum gonadotropin (PMSG; Year 1: 0, 50 and 100 IU; Year 2: 100 and 150 IU) and using semen collected from elk and 1 2 elk x 1 2 sika stags. The time from synchronization device removal (CIDR vs norgestomet) to estrus was determined through observations of mounting activity. Methods for pregnancy detection, serum progesterone (P4), estrone sulfate (E1S), pregnancy-specific protein B (PSPB) and ultrasonography, following AI (Year 1: AI, Days 28 and 48 after AI; Year 2: AI, Days 42, 53 and 100 after AI) and a 90-d natural breeding season were investigated. From available production data, body weights were compared among sika and 1 4 elk x 3 4 sika hybrids relative to age. Pregnancy rates tended (P < 0.10) to differ relative to PMSG treatment and sire; administration of 0 IU PMSG resulted in fewer hinds becoming pregnant to AI than 50 or 100 IU of PMSG. Hinds receiving 100 IU of PMSG had higher (P < 0.05) pregnancy rates than hinds receiving 150 IU PMSG. Time to standing estrus did not differ (P > 0.10) between the CIDR and norgestomet groups. Pregnancy rates 50 d after a 90-d breeding season were similar (P > 0.10) between ultrasound (70.9%) and PSPB (61.6%). Serum P4 after 90 d in breeding groups and 50 d after stag removal were higher (P < 0.05) for pregnant than open hinds. Pregnancy rates (Year 1) 48 d after AI were similar (P > 0.10) between ultrasound (49.0%) and PSPB (37.3%). Serum P4 28 and 48 d after AI were higher (P < 0.05) for pregnant than open hinds. Serum E1S was higher (P < 0.01) for pregnant than open hinds 48 d after AI. Pregnancy rates (Year 2) 100 d after AI did not differ (P > 0.10) between ultrasound and PSPB (66.7%). Serum P4 was higher (P < 0.03) in pregnant than open hinds at 42, 53 and 100 d after AI. At 100 d after AI, pregnant hinds had higher (P < 0.002) serum E1S than open hinds. At 6 to 8 and 11 to 13 mo of age, 1 4 elk x 3 4 sika males tended (P < 0.08) to be heavier than sika males, while 1 4 elk x 3 4 sika females were heavier (P < 0.05) than sika females at all ages. In summary, this study documents the use of AI and methods for pregnancy detection in sika hinds as well as preliminary information regarding the production of elk-x-sika hybrids.