Effect Of Different Timed Insemination Techniques On The Conception Rate Of Sheep

【Objective】The best simultaneous estrus synchronization processing method and the estrus-timed insemination technology was studied for Chinese Merino(Junken Type)in this study,in order to provide the basis for improving the reproductive efficiency in sheep.【Methods】The estrus synchronization effect of the Chinese Merino(Junken Type)was studied by three methods,progesterone vaginal sponge suppository with PMSG,CIDR suppository with PGF2α,injected PGF2α with intramuscular by two times.the effect of three methods were compared and analyzed on the ewes estrus.First,the ewes peripheral blood of different treated time,including 1d before embedding,7d for embedding,13 d for embedding as 0h for withdrawal,48 h for withdrawal with intramuscular injection of PMSG,was collected in progesterone vaginal sponge suppository with PMSG,The concentration of estradiol(E2),follicle stimulating hormone(FSH),luteinizing hormone(LH)and progesterone(P)in peripheral blood was detected by ELISA methods.The content changes of reproductive hormone in peripheral blood were analyzed before and after estrus synchronization treatment;three different timed insemination techniques of conventional artificial insemination,deep cervical insemination and abdominal endoscopic uterine insemination were used,respectively.At the four time points of 24 h,36h,48 h and 72 h after the estrus treatment,the test ewes were inseminated with fresh essence,and the conception rate of the ewes were analyzed by comparing the different insemination techniques and different insemination times.【Results】The estrus synchronization rate of Chinese Merino(Junken Type)treated with progesterone vaginal sponge suppository with PMSG,CIDR suppository with PGF2α injected PGF2α with intramuscular by two times was compared and analyzed.The results showed that the estrus synchronization time of ewes was concentrated in 24-48 hours after the same estrus synchronization treatment;the estrus synchronization rate of progesterone vaginal sponge suppository with PMSG treatment group(87.5%)and CIDR suppository with PGF2α treatment group(92.5%)was significantly higher than those of sheep treated with two intramuscular injection of PGF2α(65%)(P < 0.05).ELISA was used to detect reproductive hormone levels in peripheral blood of ewes treated with progesterone sponge suppository plus PMSG at four time points,The results showed that the levels of E2,FSH and LH in peripheral blood of 48 h for withdrawal with intramuscular injection of PMSG were significantly higher than those of 1d before embedding,7d for embedding and 13 d for embedding as 0h for withdrawal(P < 0.05).The fluctuation of hormone content was consistent with estrus performance at that time point.The results showed that the fertility rates of ewes treated with conventional artificial insemination,deep cervical orifice insemination and endoscopic horn insemination were 37.50%,43.75% and 63.75% respectively.The fertility rates of ewes treated with endoscopic horn insemination were significantly higher than other two groups(P < 0.05).【Conclusion】 The treatment of progesterone vaginal sponge suppository with PMSG and CIDR suppository with PGF2α had good estrus synchronization effect in Chinese Merino(Junken Type).48 hours after the treatment of progesterone vaginal sponge suppository with PMSG was the best time to carry out artificial insemination,and high fertility rate could be obtained by timing insemination of uterine horn under abdominal endoscope.