|
|
第四十卷(2011)
乳牛群單日乳產量高於55公斤之月齡與乳質研究
吳明哲(1)、賴永裕(1)、林秀蓮(1)、張菊犁(1)、李素珍(1)、陳志毅(1)、施意敏(1)、黃英豪(1)、 陳榮泰(2)、丁進來(2)、岳佩瑩(3)、陳中興(3)
(1)行政院農業委員會畜產試驗所 (2)中華民國乳業協會 (3)行政院農業委員會畜牧處
應用DHI資訊把單日乳產量高於55 kg的高乳量牛，檢視其乳質性狀，作為乳量乳質兼顧的選拔依據。因此，本研究自2001年1月至2011年10月間DHI資料庫www.angrin.tlri.gov.tw選取單日乳產量高於55 kg之乳樣記錄，進行產乳月齡及其乳質研究。至2011年10月，單日乳量記錄最高為72.2 kg，高於55 kg有511名，單日乳產量平均 57.9+3.0kg，乳牛檢測月齡平均為64.3+19.2月齡，產乳月齡範圍為24~157月齡。產乳月齡60月齡以內，有45%(234/511)。單日乳產量高於55 kg的511名之乳脂肪率(F)、蛋白質率(P)、乳糖率、體細胞數、尿素氮、枸櫞酸、以及P/F比值之平均+標準偏差分別有3.17+0.81%、2.89+0.25%、4.79+0.26%、17.7+39.6萬細胞/mL、12.3+5.3mg/dL、187+27mg/dL、以及0.96+0.26。當與2010年台灣乳牛168,913乳樣之乳脂肪率(3.74%)、蛋白質率(3.30%)、P/F比(0.91)、乳糖率(4.77%)及體細胞數平均33.3萬細胞/mL來比較，單日乳量高於55kg等乳樣之乳脂肪率及蛋白質率明顯地較低，不過單日乳量高於55kg等乳樣之乳質有關的體細胞數平均較2010年台灣乳牛體細胞數平均也較低，顯示高乳量僅降低脂肪率及蛋白質率。因此，台灣乳牛育種策略上，可以乳量、乳質及繁殖性狀兼顧的選拔方向，來培育具有適應濕熱環境特色的台灣乳牛。
關鍵語：乳牛、選育、乳質
DAIRY COWS HAVING GREATER THAN 55 KG OF DAILY MILK YIELD ASSOCIATED TO MONTH OF AGE AND MILK QUALITY
M. C. Wu(1), Y. Y. Lai(1) , H. L. Lin(1), C. L. Chang(1), S. J. Lee(1), J. Y. Chen(1), E. M. Shy(1), I. H. Hwang(1),L. T. Chen(2), J. L. Ding(2), P. Y. Yue(3) and C. S. Chen(3)
(1)Livestock Research Institute, Council of Agriculture, Executive Yuan; (2)Dairy Association of ROC; (3)Animal Industry Division, Council of Agriculture, Executive Yuan
Breeding scheme of dairy cattle, selection on milk yield and quality associated with reproductive performance is essential to the hot and humid weather, and therefore selected cows will become a heat-tolerance line in Taiwan. Data were used to study the top records on daily milk yield having greater than 55 kg and their age and milk quality from January of 2001 to October of 2011 based upon www.angrin.tlri.gov.tw. The highest record of 72.2 kg on daily milk yield was recorded and there were a total of 511 records having greater than 55 kg on daily milk yield, and with a mean of 57.9+3.0kg. A mean of milking age was 64.3+19.2 months old with ranging between 24 and 157 months of age. There was 45% (234/511) of those cows having highest daily milk yield within 60 months of age. For those of Top 511 cows in daily milk yield, their milk fat (F), protein (P), lactose, somatic cell counts, urea nitrogen, citric acid and P/F ratio were 3.17+0.81%, 2.89+0.25%, 4.79+0.26%, 17.7+39.6 x103/mL, 12.3+5.3mg/dL, 187+27mg/dL, and 0.96+0.26, respectively, as comparison to the average of 168,913 milk samples with 3.74% fat, 3.30% protein, 0.91 of P/F ratio, 4.77% lactose and 333x103/mL cell counts in 2010. It indicated that the top 511 cows had a significantly less fat%, protein%, and somatic cell counts. It indicated that high yield resulted in a less fat and protein percentage. In conclusion, selection on both milk yield and quality trait in those of cows having greater than 55 kg on daily milk yield would be feasible along with improvement on quality traits including of milk fat, protein, lactose and somatic cell counts under a breeding scheme for dairy cattle in Taiwan.
Key Words: Dairy cattle, Selection, Milk quality
  
|
|
|
|
| 所徽 |
|
|
|
