• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.91-91
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• 2003

소의 생산성 향상을 위해서는 번식효율의 증진과 개체의 유전능력을 충분히 발휘할 수 있도록 적절한 사양관리를 실시하여야 한다. 특히 번식관리는 발정관찰로부터 출발하며 발정관찰의 원활한 수행이 없이는 좋은 번식성적을 기대할 수 없다. 그러나 발정관찰은 많은 시간과 노동력이 요구되며 이로 인하여 발정관찰방법과 보조기구가 개발되어 시판되고 있다. 본 연구는 발정관찰의 편리성과 정확성을 개선하고자 (주)한경게놈텍에서 개발한 무인발정관리시스템(HMS)을 활용하여 발정발현양상을 분석하였다. 실험에 공시된 시험축은 안성인근 지역에서 사육되는 35두의 홀스타인 경산우를 선발하였으며, 발정주기에 관계없이 무작위로 선발하여 미근부에 감지센서를 부착하고 감지시간을 0.1초 이상으로 설정하여 매직닥터를 설치하였다. 발정감지횟수와 감지시간의 분석은 승가허용 감지시간이 0.5초 이상인 것만을 승가허용으로 간주하고 분석하였다.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1566-1573
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• 2006

The study was conducted on 30 true acyclic Sahiwal cows (15 cows, ${\geq}90$ days postpartum; 15 postpubertal heifers, ${\geq}30$ months of age) and a similar 20 untreated controls (10 cows, 10 heifers). An 'Eazi' breed Controlled Internal Drug Release (CIDR) device (containing 1.38 g progesterone) was inserted intravaginally for 7 days (days 0 to 7) followed by 500 IU eCG i.m. at CIDR removal in all the treated animals. Heifers also received 5 mg oestradiol valerate i.m at CIDR insertion. The reproductive performance of these animals was recorded in terms of oestrus induction response, conception and pregnancy rates. Plasma progesterone ($P_4$) and oestradiol-$17{\beta}$ ($E_2$) profiles of 4 representative animals from each treatment group before, during and after CIDR treatment were also monitored. An oestrus induction response of 100% was observed in treated cows and heifers. The majority of cows (53.3%) and heifers (60%) were induced to oestrus within 24-36 and 36-48 h, respectively after CIDR withdrawal; with mean intervals of $44{\pm}3.18$ and $48{\pm}2.35h$, respectively. The conception rate at induced oestrus was higher in cows (40%) than heifers (20%). The final pregnancy rates after 2 subsequent oestruses were 80 and 60% in cows and heifers, respectively (overall 70% for all treated animals). In comparison, only 10% of control animals (2 cows only, 2/20) showed oestrus and become pregnant (10%) during theentire study period. The pretreatment (day 0) mean plasma P4 levels were statistically (p>0.05) similar in cows and heifers ($0.40{\pm}0.04$ and $0.49{\pm}0.11ng/ml$, respectively). The peak $P_4$ levels were observed on day 1 in cows ($13.94{\pm}1.41ng/ml$) and day 2 in heifers ($19.15{\pm}3.30ng/ml$) with a progressive decline up to the day of CIDR withdrawal ($3.35{\pm}0.92$ and $8.79{\pm}1.71ng/ml$, respectively). Mean $P_4$ levels on day 9 and 10 in cows and heifers did not differ significantly from their respective day 0 values and the lowest values were recorded on day 10 both in cows and heifers ($0.13{\pm}0.03$ and $0.14{\pm}0.02ng/ml$, respectively). Wide variations in individual pretreatment $E_2$ levels were observed both in the cows (range = 4-26, mean = $13.00{\pm}4.65pg/ml$) and heifers (range = 10-14, mean = $11.50{\pm}0.96pg/ml$). Thereafter also, $E_2$ levels in cows showed variation and reached a peak level ($53.50{\pm}2.99pg/ml$) on day 8. In heifers, peak mean $E_2$ level ($111.25{\pm}39.81pg/ml$) was recorded on day 1, followed by a non-significant decline on day 2, a significant fall on day 6 and a non-significant increase on day 9 and 10. However, mean $E_2$ levels on days 7 (p<0.05), 8 and 9 (p<0.01) were significantly higher in cows compared to heifers. The post-CIDR withdrawal mean highest $P_4$ and lowest $E_2$ levels coincided with the period when the majority of animals were induced to oestrus. CIDR and eCG treatment resulted in effective induction of oestrus with satisfactory pregnancy rates in true acyclic Sahiwal cows and heifers.