比較BLAD-雜合型與正常型荷蘭母牛的泌乳性狀

牛隻帶有單一的牛淋巴球黏力缺失症基因（BLAD-carrier）者之外觀與正常型（TL）牛隻相同。為了解此不同遺傳型母牛的泌乳性能，檢測693頭經產且參加DHI測乳的荷蘭母牛DNA，其中653頭為正常型牛隻，40頭為帶有淋巴球黏力缺失症基因的雜合型（BL）牛隻，雜合型比例為5.8％。整理693隻已檢測遺傳型母牛的DHI月測乳資料，歷年計10,191筆測乳記錄。以乳量、乳脂量及體細胞分數等為主要分析應變數，資料分析時自變數除不同遺傳型之外，亦包含場別、年代、季節、產次及測乳日齡等變數或共變數。計算各項效應，結果顯示場別、季節、產次效應與年代效對應變數影響很大，但不同的遺傳型間除體細胞數與體細胞分數外對各乳品質性狀並無顯著影響。雜合型母牛與正常型母牛的測乳量分別為21.52 kg與21.13 kg，修正305-2X-ME乳脂量為247.9 kg及244.1 kg，乳蛋白質百分率為3.154％與3.179％，乳脂率和乳糖率分別為3.644％與3.677％，以及4.640％與4.652％。但二種遺傳型的修正305-2X-ME乳量分別為6968 kg及6774 kg，乳中體細胞數評分為5.156分及4.519分，體細胞數分別為91.93萬／ml及68.77萬／ml，雜合型雖有稍高的乳產量但體細胞數卻較高。因此淘汰此項遺傳突變基因對泌乳牛群生產效率應無顯著之負面影響。

關鍵字

雜合型；牛淋巴球黏力缺失症；泌乳性狀

並列摘要

Cows with one Bovine Leukocyte Adhesion Deficiency gene (BLAD-carrier, BL) have a similar outer appearance as a normal cow (TL). The aim of this study was to compare the milk production and quality between BLAD-carrier and normal cows. DNA were sampled and tested from five DHI program farms. After exclusion of cows lacking DHI record, 40 carriers were found in a total of 693 cows with lactation data. The frequency of BLAD-carriers was 5.8%. Based on DHI monthly sampling system, 10,191 lactation records were available for these 693 cows. In addition of genotypes (TL and BL), the independent variables were herd, year, season, parity and a covariant, days of age. Dependent variables were 305-2X-ME milk, 305-2X-ME fat, test-day milk, fat %, protein %, lactose %, somatic cell score and somatic cell count. Results shows that herd, season, parity and year effects were significant for all traits, but genotype only had significance in 305-2X-ME milk, somatic cell score, and somatic cell count. Test-day milk of BLAD-carrier and normal cows were 21.52 kg and 21.13 kg; 305-2X-ME fat were 247.9 kg and 244.1 kg; percentages of milk protein, fat and lactose were 3.154% vs. 3.179%, 3.644% vs. 3.677% and 4.640% vs.4.652%. 305-2X-ME milk were 6,968 kg and 6,774 kg; somatic cell score were 5.156 vs. 4.519; and somatic cell count were 919.3 vs. 687.7 (10^3/ml). Although milk production of BLAD-carriers was slightly higher than normal cows, somatic cell count was worse than non-carriers'. These results implied that negative influence should be minor, if the BLAD mutation gene is removed from Taiwan Holstein population.

並列關鍵字

Carrier ； Bovine leukocyte adhesion deficiency ； Lactation

主題瀏覽