帶淋巴球黏力缺失症不良基因之雜合型公牛於熱帶地區之配種觀察

楊德威 黃金山 黃鈺嘉 張秀鑾

台灣省畜產試驗所

挑選帶有淋巴球黏力缺失症不良基因之雜合型公牛精液(BL)，並安排與配台灣南部某試驗牛群中的雜合型母牛(BL)與其它的正常型母牛(TL)。自1997年一月至同年十二月底共有六隻雜合型母牛與配雜合型公牛，共有四隻母牛分娩。 但是其中的一胎流產、一胎死產，而正常分娩的兩頭仔牛當中，亦有一隻仔牛於分娩後第二天即突然猝死。 遺傳檢測追蹤發現猝死仔牛是帶有兩個不良基因的有病型個體(BLAD)。 而一隻難產而死的仔牛遺傳檢測的結果為不帶此不良基因的正常型個體(TL)。 一年間共使用27 劑的雜合型冷凍精液，共有七隻母牛懷孕，受孕率估計為25.9%. 同期的 280頭次與配正常型母牛共有84隻受孕，受胎率30.0%. 回追過去五年的配種資料與美國公牛之遺傳型資訊，發現雜合型公牛與正常型公牛的實際受孕率(以有分娩才算受孕，再除以總配種次數)相似，分別為 26.4% 與 28.2%。 本項配種觀察，建議在熱帶地區應迴避帶有此不良基因的雜合型公、母牛的交配，以避開牛淋巴球黏力缺失症所帶來的嚴重損失。

關鍵語：牛淋巴球黏力缺失症、配種、熱帶地區。

IMPACT OF MATING COWS WITH CARRIER BULLS FOR BOVINE
LEUKOCYTE ADHESION DEFICIENCY IN TROPICAL AREA

T. W. Yang, J. S. Huang, Y. C. Huang and H. L. Chang

Taiwan Livestock Research Institute

Semen from carrier bulls (BL) was used to mate the carrier(BL) and normal cows(TL) in an experimental herd at south of Taiwan. From Jan,1997 to end of Dec, 1997, six carrier cows were mated with the semen. Four cows gave two normal and two abnormal births (one abortion and one stillbirth). One of the normal birth calf died only at the age of two days old and the genetic test showed the calf was a BLAD (Bovine Leukocyte Adhesion Deficiency) homozygoous recessive. But, in the stillbirth case, the genetic test showed the genotype of the calf was a homozygote normal. Twenty-seven dose BL semen mated with twenty-one cows had seven conceptions with a conception rate 25.9%. In the same period, 280 regular mates had 84 conceptions and the conception rate was 30.0%. By pedigree data and sire information, tracing back last five years records, the difference between carrier and normal bulls was not detected for conception-calving rate (total number of calvings obtained divided by total number of services), 26.4% vs 28.2%. The results strongly recommended that mating the carrier bulls with carrier cows should be avoided to eliminate the associated losses for the Bovine Leukocyte Adhesion Deficiency.

Key Words: Bovine Leukocyte Adhesion Deficiency, Mate, Tropical area .