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58.台灣乳牛單日乳量最高100名之月齡及其乳質

吳明哲⁽¹⁾、賴永裕⁽¹⁾、黃鈺嘉⁽¹⁾、張菊犁⁽¹⁾、李素珍⁽¹⁾、曾青雲⁽¹⁾、陳志毅⁽¹⁾、施意敏⁽¹⁾、王政騰⁽¹⁾、

陳榮泰⁽²⁾、丁進來⁽²⁾、王忠恕⁽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

台灣乳牛育種策略上，期望以乳量、乳質及繁殖性狀兼顧的選拔為主，來培育台灣乳牛具有適應濕熱環境的特色，成為乳牛熱帶品系，並出口東南亞國家。因此，本研究自2001年1月至2007年9月間DHI資料庫www.angrin.tlri.gov.tw選取單日乳量最高100名乳樣記錄，進行產乳月齡及其乳質研討。至2007年9月底，單日乳量記錄最高為68 kg，第100名為56 kg，最高100名乳牛檢測月齡平均為61.8+18.8月齡，產乳月齡範圍為32~121月齡。產乳月齡60月齡以內，有50%(50/100)。單日乳量最高100名之乳脂肪率、蛋白質率、乳糖率及體細胞數平均+標準偏差分別有3.37+0.91%、2.90+0.29%、4.72+0.24%及15.5+22.1萬細胞/mL。當與2006年台灣乳牛218,818乳樣之乳脂肪率(3.81%)、蛋白質率(3.30%)、乳糖率(4.79%)及體細胞數平均32.2萬細胞/mL來比較，單日乳量最高100名之乳脂肪率及蛋白質率明顯地較低，不過單日乳量最高100名之乳質有關的體細胞數平均較2006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。當依年度來看單日乳量最高記錄，自2001至2007年依序為66、62、61、63、62、63及68 kg，該牛產乳月齡依序為41、90、77、70、54、46及60 月齡，該牛飼養地依序在高雄、雲林、雲林、屏東、雲林、彰化及桃園。因此，應用DHI資訊把56 kg以上的高乳量牛的乳脂肪率、蛋白質率、乳糖率及體細胞數等乳質性狀之乳量乳質兼顧的選拔方法，有利於牛群性能之改進。

關鍵語：乳牛、選育、乳質

TOP 100 RECORDS ON DAILY MILK YIELD OF TAIWAN DAIRY COWS AND THEIR MILKING AGE AND MILK QUALITY

M. C. Wu⁽¹⁾, Y. Y. Lai⁽¹⁾ , Y. C. Huang⁽¹⁾, C. L. Chang⁽¹⁾, S. J. Lee⁽¹⁾, C. Y. Tseng⁽¹⁾, J. Y. Chen⁽¹⁾, 

E. M. Shy⁽¹⁾, C. T. Wang⁽¹⁾,L. T. Chen⁽²⁾, J. L. Ding⁽²⁾ and C. S. Wang⁽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 for exportation to Southeast Asia. Data were used to rank the top 100 records on daily milk yield and their age and milk quality from January of 2001 to September of 2007 based upon www.angrin.tlri.gov.tw. The highest of 68 kg daily milk yield was recorded and the 100^th record was 56 kg with a mean of milking age of 61.8+18.8 months old ranging between 32 and 121 months of age. There was 50% (50/100) of highest daily milk yield cows within 60 months of age. For those of Top 100 daily milk yield cows, milk fat, protein, lactose, and somatic cell counts were 3.37+0.91%, 2.90+0.29%, 4.72+0.24%, and 155+221x10³/mL, as comparison of 218,818 milking samples in 2006 in which of 3.81% fat, 3.30% protein, 4.79% lactose and 322x10³/mL. Top 100 cows had a significantly less fat%, protein%, and somatic cell counts. It indicated that high yield resulted in a less fat and protein percentage. Top record of each year from 2001 to 2007, there were 66, 62, 61, 63, 62, 63 and 68 kg, respectively, with the age of milking were 41, 90, 77, 70, 54, 46 and 60 months of age. Top record cows were raised in county of Kaohsiung, Yunlin, Yunlin, Pingtung, Yunlin, Changhua and Taoyuan. In conclusion, selection on both milk yield and quality trait in those of above 56 kg on daily milk yield cows along with traits of milk fat, protein, lactose and somatic cell counts would be feasible.

Key Words: Dairy cattle, Selection, Milk quality