Journal of Embryo Transfer (한국수정란이식학회지)

The Korean Society of Embryo Transfer (한국수정란이식학회)
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Estrus Induction Rates and Conception Rates by MGA Feeding System in Hanwoo

MGA Feeding System에 의한 발정 동기화 방법이 한우의 발정 발현율과 수태율에 미치는 영향

  • Lee, M.S. (National Livestock Research institute, R.D.A.) ;
  • Jung, Y.H. (National Livestock Research institute, R.D.A.) ;
  • Park, S.B. (National Livestock Research institute, R.D.A.) ;
  • Im, S.K. (National Livestock Research institute, R.D.A.) ;
  • Park, J.J. (National Livestock Research institute, R.D.A.) ;
  • Jung, J.K. (National Livestock Research institute, R.D.A.) ;
  • Moon, S.J. (Chonnam University) ;
  • Kim, C.K. (ChungAng University)
  • Published : 2006.09.30
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Abstract

This study was conducted to investigate the effects of melengesterol acetate (MGA) and $PGF_{2{\alpha}}$ administrations on serum progesterone level, synchrony of estrus and conception rates in Han-woo. Firstly, ten heifers and one freematin were fed 0.5 mg MGA/day for 14 days in a grain carrier, and after 19 days of MGA feeding, a single injection of 25 mg $PGF_{2{\alpha}}$ were treated. Blood samples were collected to evaluate serum progesterone concentrations from the start of feeding of MGA until the end of feeding and subsequent estrous detection and artificial insemination (AI) at 3 days intervals, and on days of $PGF_{2{\alpha}}$ injection, estrous detection, AI, and 15th and 60th days after AI. The level of progesterone in the blood began to increase from 7 days after MGA feeding, and 9 days after feeding it became 5.4 ng/ml and maintained that level thereafter. On the 33th day when the $PGF_{2{\alpha}}$ was injected, it reached the peak level of 7.6 ng/ml. However, 2-3 days after $PGF_{2{\alpha}}$ injection, it dropped to 1.4 ng/ml drastically (p<0.05). Secondly, one hundred and ninety four Hanwoo heifers or cows were divided into two groups to compare estrous induction and conception rates: the one treated with MGA and $PGF_{2{\alpha}}$, (n=104) and the other with $PGF_{2{\alpha}}$ treatment (two injections at 11 days interval, n=90). The heifers or cows treated with MGA and $PGF_{2{\alpha}}$ were identical to those used as above. The percentages of heifers or cows showed estrus were higher in the $MGA+PGF_{2{\alpha}}$ treatment (91.3%) than in the $PGF_{2{\alpha}}$ treatment (72.2%, p<0.05). Conception rates were also higher in the $MGA+PGF_{2{\alpha}}$ treatment (94.2%) than in the $PGF_{2{\alpha}}$ treatment (88.9%, p<0.05). The results of this experiment indicate that estrus synchronization using $MGA+PGF_{2{\alpha}}$ is more effective than that using $PGF_{2{\alpha}}$ (two injections) in Hanwoo.

본 연구는 $MGA+PGF_{2{\alpha}}$ 투여에 의한 발정 동기화 방법이 한우의 혈청 $P_4$ 수준, 발정 발현율과 수태율에 미치는 영향을 규명하고자 수행하였다. 첫째로, 한우 미경산우에서 $MGA+PGF_{2{\alpha}}$ 투여가 혈청 $P_4$ 수준에 미치는 영향을 조사하기 위하여 한우 미경산우 10두 및 프리마틴 1두에 대하여 MGA를 1일 0.5 mg을 14일간 오전 배합 사료에 섞어 급여하였으며, 19일이 경과한 후에 $PGF_{2{\alpha}}$ 25 mg을 투여하였다. MGA feeding 후 혈청 $P_4$ 농도 수준을 분석하기 위하여 MGA 급여 기간과 급여 종료 후 발정이 관찰될 때까지는 3일 간격, $PGF_{2{\alpha}}$ 투여 시, 발정 및 인공 수정 시, 인공 수정 후 15일째 및 2개월째에 혈액을 채취하였다. 한우 미경산우의 혈청 $P_4$ 수준은 MGA급여 7일 이후부터 상승하기 시작하여 투여 9일차에는 5.4 ng/ml로써 이후 상승된 상태에서 유지되었다. $PGF_{2{\alpha}}$ 투여시점인 33일차에는 7.6 ng/ml 수준으로 피크를 나타냈고, 투여 2-3일이 경과하고 발정이 발현됨에 따라 1.4 ng/ml로 급강하하는 양상을 보였다(p<0.05). 그러나 프리마틴의 경우에는 시험 기간 동안 P4수준의 변화가 인정되지 않았다. 둘째로, 한우 미경산우 및 경산우 194두를 이용하여 상기한 $MGA+PGF_{2{\alpha}}$ 투여 방법(n=104)과 대조군으로 $PGF_{2{\alpha}}$ 투여(11일 간격 2회 투여, n=90)에 따른 발정 발현율 및 수태율을 비교하였다. 발정 발현율은 대조군인 $PGF_{2{\alpha}}$ 투여군 72.2%에 비해 $MGA+PGF_{2{\alpha}}$ 투여군에서 91.3%로써 유의적으로 높았다(p<0.05). 인공 수정 후 수태율은 $MGA+PGF_{2{\alpha}}$ 투여군이 $PGF_{2{\alpha}}$ 투여군에 비해 1회 수정 수태율(51.1 vs. 59.6%), 2회 수정 수태율(77.8 vs. 84.6%) 및 전체 수태율(88.9 vs. 94.2 %)이 유의적으로 높았다(p<0.05). 본 연구의 결과는 $MGA+PGF_{2{\alpha}}$를 이용한 발정 동기화 방법은 $PGF_{2{\alpha}}$ 투여법에 비해 높은 발정 동기화율 및 수태율을 나타냄으로서 한우의 번식 능력 향상에 적절히 활용될 수 있음을 보여준다.

Keywords

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