林德育 黃鈺嘉 李世昌 張秀鑾 張菊犁 李素珍 曾青雲 陳志毅 吳明哲
遺傳檢測72個參加DHI牧場的總乳混合DNA，發現有65 場中仍至少有一頭母牛帶有淋巴球黏力缺失症((bovine leukocyte adhesion deficiency, BLAD)基因，但沒有發現任何牧場有雜合型的單譜症(Deficiency of Uridine Monophosphate Synthase, DUMPS) 泌乳牛。四個場的資料無法清楚的判讀 BLAD結果，其中兩場為直接採樣的新鮮總乳餘兩場為DHI乳品質檢測過的總乳，體細胞數分別為 11.8、20.0、20.9、94.0萬/毫升。因此體細胞數、短期儲存與牛乳添加劑並非影響檢測靈敏度的主要因素。高頻率的BLAD雜合型提醒DHI計畫需持續宣導公牛與精液的篩選，總乳檢測方法可以監控牛群遺傳動態與降低檢測成本。
MONITORING DEFECT GENE OF DHI HERDS BY TANK MILK ─ I. BLAD AND DUMPS ALLELES
D. Y. Lin, Y. C. Huang, S. C. Lee, H. L. Chang, C. L. Chang
S. J. Lee, C.Y. Tseng, J.Y. Chen, and M.C. Wu
Taiwan Livestock Research Institute, Council of Agriculture
A genetic test screened DNA mixes of tank milk from 72 DHI herds. Results showed 65 herds had at least one cow carrying BLAD(bovine leukocyte adhesion deficiency) defect gene but none of 72 herds had any DUMPS (deficiency of uridine monophosphate synthase syndrome) carriers found. Four herds with uncertain typing results for BLAD test, two were extracted from fresh tank milk and the other two were from used DHI samples. The somatic cell counts were 118、200、209、940 103/ml, respectively. Milk storage period, somatic cell counts and added preventives were not important factors for test sensitivity. The high frequency of BLAD carrier farms indicated continuous selection of TL (tested free of BLAD) bull and semen for breeding DHI cows is important. Genetic test by tank milk is an economic approach to monitor genetic status of dairy population efficiently.
Key words: Tank milk, DNA mixes, BLAD, DUMPS.