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第三十五卷(2006)
77.天噸乳牛產乳性狀與繁殖性狀之選拔
吳明哲(1)、黃鈺嘉(1)、張菊犁(1)、李素珍(1)、曾青雲(1)、陳志毅(1)、陳榮泰(2)
(1)行政院農業委員會畜產試驗所 (2)中華民國乳業協會
天噸乳牛是指一頭泌乳牛在台灣濕熱氣候下，自開始測乳後的平均每一個泌乳期(305-2X-ME)就能夠生產牛奶超過10,000公斤以上的乳量，亦就是年產乳量有10公噸以上，10公噸的英文是Ten Tons，取其音取其義，我們稱這種乳牛為天噸乳牛(Ten Tons Cow)。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，成為熱帶品系，並出口東南亞國家。自2001年完檢的天噸乳牛頭數32頭(僅為該年28,381頭測乳牛之0.1%)，增加至2002年的103頭，至2003年的146頭，至2004年的254頭，至2005年的312頭(為該年37,820頭測乳牛之0.8%)，五年來，天噸乳牛頭數成長率達9倍(312/32)。從2001至2005年完檢的天噸乳牛月齡平均分別為52、57、50、56、55月；乳量育種價分別為+1113、+988、+1051、+960、+949 kg；脂肪量育種價分別為+41、+32、+40、+34、+35 kg。2006年測乳中的33,064頭牛有1,135頭(佔3.4%)天噸乳牛，其乳量育種價為+894 kg及脂肪量育種價為+33 kg，分散在150戶(佔測乳戶293戶之51.2%)；其中擁有10頭以上的戶數有40戶(佔測乳戶293戶之13.7%)，合計有797頭，佔70.22%。再分析2006年測乳達12公噸以上乳量的牛隻有44頭，其平均月齡為44月，平均測乳次數12次(等同於第二胎)；其中有8頭是三胎以上的牛。因此，應用超高乳量的天噸乳牛來進行乳量、乳質及繁殖性狀兼顧的選拔，將有利於牛群性能之改進。
關鍵語：乳牛、選育、乳量
SELECTION ON REPRODUCTIVE PERFORMANCE ASSOCIATED WITH MILK YIELD OF TEN TONS COW
M. C. Wu(1), Y. C. Huang(1), C. L. Chang(1), S. J. Lee(1), C. Y. Tseng(1), J. Y. Chen(1) and L. T. Chen(2)
(1)Livestock Research Institute, Council of Agriculture, Executive Yuan; (2)Dairy Association of ROC
Ten Tons Cow is designated as milk yield of 305-2X-ME greater than 10,000 kg for hot and humid environment in Taiwan. For 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. In 2001, there were 32 test-off Ten Tons Cow (0.1% to 28,381 cows for milk test), and then number of cows up to 103 head in 2002, 146 head in 2003, 254 head in 2004, and 312 head (0.8% to 37,820 cows for milk test) in 2005. An increment of 9 times (312/32) for the number of ten tons cows for the past five years. From 2001 to 2005, age of test-off Ten Tons Cow were 52, 57, 50, 56, and 55 months old, respectively; along with breeding value on milk yield (BVM) of +1113, +988, +1051, +960, +949 kg; and on fat yield (BVF) of +41, +32, +40, +34, +35 kg, respectively. In 2006, there were 1,135 head of Ten Tons Cow (3.4% to 33,064 cows for milk test) with BVM of +894 kg and BVF of +33 kg. Those of Ten Tons Cow were raised in 150 farms (51.2% to 293 testing farms) and among of 40 farms (40/293=13.7%) having more than 10 cows with a total of 797 head (70.22% to 1135 head). A total of 44 cows was selected with more than 12-tons milk yield with a mean of 44 months of age after 12 times of milk test in average, based upon number of milk test equivalent to their second lactation, in 2006. Among of them, 8 out of 44 had more than three lactations. In conclusion, application of milk yield and quality associated with reproductive performance would be feasible to improve herd performance in dairy cattle.
Key Words: Dairy cattle, Selection, Milk yield
  
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