# 유우(乳牛)의 혈청(血淸)과 유즙중(乳汁中)의 호르몬수준(水準)에 의한 임신진단(姙娠診斷)에 관한 연구(硏究)

• Kim, Sang-keun (Department of Veterinary Medicine, College of Agriculture, Chungnam National University)
• 김상근 (충남대학교 농과대학 수의학과)
The study was carried out to find out the changes of hormone levels in blood serum and milk of Holstein cows during the estrous cycle. The progesterone, estradiol-$17{\beta}$ from the blood serum and milk samples were assayed by radioimmunoassay methods. The results of this study were summarized as follows; 1. The progesterone levels in blood serum during the estrous cycles began to decline rapidly at 2 days before estrus, decreased to $0.27{\pm}0.18ng/ml$ at on the day of estrus, and reached a peak mean level of $3.33{\pm}0.47ng/ml$ at 15 days after estrus. 2. The progesterone levels in milk during the estrous cycles began to decline rapidly at 2 days before estrus, decreased to $0.80{\pm}0.18ng/ml$ on the day of estrus, and increased a peak mean level of $3.80{\pm}0.36ng/ml$ at 15 days after estrus. 3. The estradiol-$17{\beta}$ levels in blood serum during the estrous cycles showed a peak mean level of $9.79{\pm}1.72pg/ml$ on the day of estrus, and decreased from $4.79{\pm}1.82pg/ml$ to $5.73{\pm}0.96pg/ml$ at luteal phase. 4. The estradiol-$17{\beta}$ levels in milk during the estrous cycles showed a peak mean level of $36.80{\pm}2.04pg/ml$ on the day of estrus, and decreased from $18.93{\pm}0.84pg/ml$ to $19.50{\pm}1.12pg/ml$ at luteal phase. 5. During 20 to 25 days after artificial insemination, the accuracy of pregnancy diagnosis from the blood serum progesterone levels were 87.5% for non pregnant cows (<2.0ng/ml), and 83.3% for pregnant cows ($${\geq_-}$$3.0 ng/ml). The accuracy of pregnancy diagnosis from the milk progesterone levels were 75.0% for non-pregnant cows (<2.4 ng/ml), and 94.4% for pregnant cows ($${\geq_-}$$3.2 ng/ml).