Studies on Pregnancy Diagnosis of Dairy Cows based on Hormone Concentrations in Blood Serum and Milk |
Sang-keun Kim |
Department of Veterinary Medicine, College of Agriculture, Chungnam National University |
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) |
김상근 |
충남대학교 농과대학 수의학과 |
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Abstract |
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-$17{eta}$ 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-$17{eta}$ 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-$17{eta}$ 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). |
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