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36.DHI乳牛群之脊椎畸形複合症(CVM)基因型頻率

林德育　黃鈺嘉　曾青雲　楊德威　李世昌　吳明哲

行政院農業委員會畜產試驗所

脊椎畸形複合症（Complex Vertebral Malformation, CVM）是一種已發現於荷蘭乳牛的致死隱性遺傳缺陷，導致母牛早產或是死產而造成酪農經濟損失。台灣的荷蘭乳牛為生產用單一乳用品種，並廣泛使用進口冷凍精液。本研究利用聚合酶連鎖反應(PCR)與單股構形多態性 (Single Strand Conformation Polymorphism, SSCP)方法來檢測此一遺傳疾病，由DHI乳樣進行篩檢，並估計台灣荷蘭牛泌乳牛群脊椎畸形複合症之頻率。檢測來自132 個DHI乳牛場共856 頭泌乳牛乳樣。在856頭荷蘭種泌乳牛中有98頭為雜合型個體牛(CV)，758頭為正常型牛(TV)，所有檢測樣本中未存在有病型(CVM)個體，雜合型牛之頻率達11.4 %。通常隱性純合子型的胚胎會胎死腹中，故正如預期地並未檢測出隱性純合子型的有病型(CVM)個體。依本研究的數據可估計現階段台灣牛群中，脊椎畸形複合症的雜合型個體(CV)的頻率約在10%以上。

關鍵語：脊椎畸形複合症、聚合酶連鎖反應、單股構形多態性

GENOTYPE FREQUENCY OF COMPLEX VERTEBRAL
MALFORMATION OF DHI HOLSTEIN COWS

D. Y. Lin, Y. C. Huang, C. Y. Tseng, T. Y. Yang, S. C. Lee and M. C. Wu

Livestock Research Institute, Council of Agriculture

Complex Vertebral Malformation, CVM, is a lethal genetic defect in Holstein dairy cattle and refers to a combination of symptoms that include fused or misshapen vertebrae, contracted joints in the front and rear legs, and reduced body size. In Taiwan, Holstein breed is the only breed for dairy production and cows of DHI herds are now inseminated by using imported frozen semen. A total of 856 milk samples from 132 DHI farms were collected and extracted DNA for the test. CVM genotypes were tested by PCR-SSCP method. Ninety-eight samples were detected as CVM carriers (11.4%, 98/856). Due to the fact that most individuals having homozygous recessive genotype would die in embryonic or fetal stage, no homozygous recessive animal was detected in this investigation. The estimated percentage of CVM carrier Holstein cows in Taiwan is about 10 %.

Key Words: Complex vertebral malformation, PCR, SSCP