• 한국수정란이식학회지
• /
• 제23권2호
• /
• pp.81-86
• /
• 2008

This study compared the pregnancy rates of Korean native donor cattle after either a timed artificial insemination (TAI) or embryo transfer (TET) following the synchronization of ovulation using a controlled internal drug release (CIDR) device together with estradiol benzoate (EB) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$). Fifty five cows and 8 heifers which had been previously used for embryo production were assigned to two treatments: (1) Thirty-two cattle received a CIDR device and 2 mg EB (Day 0), 25 mg $PGF_{2{\alpha}}$ injection at the time of CIDR removal on Day 7, and 1 mg EB injection on Day 8. All of the cattle received a TAI 30 h (Day 9) after the second EB injection (TAI group). (2) Thirty-one cattle received the same hormonal treatments as in the TAI group. The cattle with corpus luteum (CL) received a TET on Day 16 using frozen-thawed embryos (TET group). Ultrasonographic observations demonstrated that the proportion of cattle with synchronized ovulation on Day 10 and the concomitant formation of new CL on Day 13 did not differ between groups (p>0.05); the overall mean rates were 65.1 and 73.0%, respectively. The conception and pregnancy rates did not differ (p>0.05) between the TAI (12.5% and 12.5%) and TET groups (13.0% and 9.7%), respectively. We conclude that the pregnancy rate following TAI or TET in Korean native donor cattle was poor, which might be due in part to a poor synchrony of ovulation and concomitant CL formation.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권6호
• /
• pp.774-780
• /
• 2009

The objectives of this study were to test the efficacy of induction of estrus and determine the timing of ovulation in relation to preovulatory LH and estrogen surges in cycling Murrah buffaloes subjected to Heatsynch protocol (GnRH-$PGF_2{\alpha}$-Estradiol benzoate). In experiment 1, the buffaloes (n = 10) were treated with Heatsynch protocol and observed for estrus and ovulation. In experiment 2 and 3, 30 cycling Murrah buffaloes were used to investigate the efficacy of Heatsynch protocol in terms of conception rates in summer (experiment 2) and winter (experiment 3) seasons. Fixed time A.I. was performed in all the buffaloes at 48 and 60 h post-estradiol benzoate (EB) injection. All buffaloes responded to the Heatsynch protocol with expression of estrus for which ovulations were induced in 8 buffaloes (80%). Mean time interval from the EB injection to ovulation was 50.0${\pm}$2.0 h (range 44.0 to 60.0 h). The interval from the end of LH surge to ovulation was 18.5${\pm}$2.47 h (range 8 to 26 h). The interval from end of estrogen surge to ovulation was 26.75 ${\pm}$2.07 h (range 22 to 36 h). Mean LH peak after EB injection occurred at 20.81${\pm}$1.61 h (range 14 to 28 h) and mean estrogen peak after EB injection occurred at 9.62${\pm}$1.03 h (range 7 to 16 h). Hence, the mean estrogen peak preceded the mean LH peak by 11 h. It was observed that the percentage of conceptions to total number of estruses for control buffaloes was 18 and 30 in summer and winter, respectively, whereas it increased to 26 and 40 in Heatsynch treated buffaloes in respective seasons. The results suggest the possibility of using Heatsynch treatment followed by fixed time A.I. in buffaloes for fertility improvement, especially since the incidence of silent heat in buffaloes is very high.

• 한국임상수의학회지
• /
• 제31권5호
• /
• pp.382-388
• /
• 2014

본 연구는 젖소에서 배란동기화 프로그램 적용 후 임신율에 영향을 미치는 요인을 분석하기 위하여 실시하였다. 분석에 포함된 자료는 젖소 목장 22개소내 사육 젖소 1,952두에 정시 인공수정을 위하여 실시한 배란동기화 프로그램(PG+EB, Ovsynch, CIDR-ovsynch), 젖소의 산차, 신체상태지수(BCS), 전 산차 분만일, 인공 수정일 및 임신 진단 결과를 포함하였으며, 통계분석은 SAS 로지스틱 회기분석을 이용하였다. 분석 결과, 목장(p = 0.005), 산차(p = 0.0001), BCS(p < 0.005) 및 인공수정 계절(p < 0.05)이 유의적으로 임신율에 영향을 미쳤으며, 공태기간은 경향성을 나타내었다(p < 0.1). 배란동기화 프로그램에 따른 임신율의 유의적인 차이는 인정되지 않았으나, 산차와 배란동기화 프로그램 사이에 교호관계가 성립되었다(p < 0.005). PG+EB 프로그램을 사용 시에는 초산 차에 비해 2산 이상의 경산우에서 임신율의 감소(odds ratio [OR]: 0.60, p < 0.0001)가 있었으나, Ovsynch 프로그램을 사용 시에는 초산 차에 비해 2산 이상의 경산우에서 임신율이 증가하는 경향이 있었으며(OR: 1.44, p < 0.1), CIDR-ovsynch 프로그램을 사용 시에는 초산 차와 2산 이상의 경산우에서 임신율의 차이가 없었다(p > 0.05). BCS가 3.00을 이상일 때가 2.75 이하일 때 보다 1.41배 임신 가능성이 증가되었으나, 인공수정을 여름에 실시할 때가 봄에 실시할 때에 비해 임신 가능성이 0.73배로 감소되었다. 인공 수정 시 공태기간이 150일을 경과 할 때가 150일 미만일 때 보다 임신 가능성이 1.20배 증가 경향이 있었다. 결론적으로, 젖소에서 배란동기화 프로그램 적용 후, 목장, 젖소의 산차, BCS, 공태기간 및 인공수정 계절이 임신율에 영향을 미치는 중요한 요인이었다. 또한 배란동기화 프로그램과 산차 사이 교호관계가 성립되었으며, PG+EB 프로그램 사용 시 초산 차에 비해 2산 이상의 경산우에서 임신율의 감소가 있었다.