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每個人都是自己幸福的建築師。
[克羅底亞斯] |
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第三十四卷(2005)
繁殖能力登錄乳牛的初產月齡、胎數及胎距
吳明哲 李世昌 黃鈺嘉 張菊犁 李素珍 曾青雲 陳志毅
行政院農業委員會畜產試驗所
經產母牛合於五歲三胎的繁殖能力登錄頭數增多是乳牛繁殖性能的評估要項，故計算母牛群之五歲三胎繁殖登錄合格牛百分比(RR%)有助於提昇母牛使用年限。網路DHI庫有來自458戶的血統登錄母牛56066頭，平均每戶完成122頭血統登錄紀錄筆數，其中有18506頭牛滿五歲。滿五歲母牛中有9086頭已產下三胎，RR%為49.1% (9086/18506)，RR母牛分散於360戶，顯示78.6% (360/458)的戶數有能力達到五歲三胎繁殖管理目標。RR牛50頭以上的地區有12區，RR牛頭數地區排名，台南有1949頭最多，彰化1696頭次多。各區的RR%，在台南有54.3% (1949/3589)、彰化有49.7% (1696/3326)、嘉義有58.2% (1506/2586)、屏東有40.5% (1277/3148)、雲林有46.3% (961/2072)、高雄有47.7% (559/1171)、苗栗有50.7% (462/910)、花蓮有36.5% (168/460)、台中有48.4% (145/299)、新竹有36.3% (139/382)、桃園有41.9% (133/317)、南投有50.4% (52/103)，RR%介於36.3~58.2%。繁殖性能分析上，選用台南、彰化、嘉義、屏東及雲林等五地區的最年輕100頭RR母牛，初產月齡分別為27.0+3.4、27.2+3.3、26.2+2.9、26.8+3.7、29.8+3.5；第三胎月齡為54.1+3.4、54.2+3.6、53.9+4.2、54.6+3.7、57.1+3.8；胎距為398+54、392+50、394+47、389+46、383+43。個別場分析上，RR母牛頭數最多的一戶是雲林歐陽申助，RR%為62.6% (132/211)，其RR母牛之初產月齡為26.4+3.1、胎數為4.37+1.38、胎距為413+43及最高產次月齡為72.6+19.8。第一家政府核發的彰化王百練種牛場RR%為42.2% (62/147)，RR母牛之初產月齡為27.3+3.6、胎數為5.03+1.88、胎距為416+37、以及最高產次月齡為83.6+27.1。再者，自1996至2005年的DHI牛群之乾乳年齡平均為5.29、5.29、5.33、5.25、5.22、5.17、5.09、5.05、5.02、5.12歲，逐年減低。因此，當設定乾乳年齡平均七歲為繁殖管理目標以提昇母牛使用年限時，能再以初產月齡26月、五歲三胎、前三胎胎距383天及七歲五胎等繁殖指標來選留高等繁殖登錄母牛，促使乳牛初產月齡減低及胎距縮短。
關鍵語：乳牛、繁殖登錄、胎距
AGE AT FIRST CALVING, NUMBER OF CALVING AND CALVING
INTERVAL IN COWS WITH REPRODUCTION REGISTRATION
M. C. Wu, S. C. Lee, Y. C. Huang, C. L. Chang, S. J. Lee, C. Y. Tseng and J. Y. Chen
Livestock Research Institute, Council of Agriculture, Executive Yuan
Cow having three calving within five years old (RR cow) is essential to reproductive performance of cows in a dairy herd. Percentage of RR cows (RR%) is useful for lifespan improvement of cows. Data of 56066 cows from 458 farms with 122 cows per farm were used and 18506 cows had five years old. RR cows were raised at 360 farms and 78.6%(360/458) of farms having RR cows. Among various areas, the RR% was 49.1% (9086/18506) in total with a range of 36.3~58.2%. Tainan had 1949 head in 1st rank among 12 areas and Chunghu in 2nd rank with 1696 head. The RR% was 54.3% (1949/3589) in Tainan, 49.7% (1696/3326) in Chunghu, 58.2% (1506/2586) in Chiayi, 40.5% (1277/3148) in Pingtung, 46.3% (961/2072) in Yulin, 47.7% (559/1171) in Kaohsiung, 50.7% (462/910) in Miaoli, 36.5% (168/460) in Hualien, 48.4% (145/299) in Taichung, 36.3% (139/382) in Hsinchu, 41.9% (133/317) in Taoyuan, and 50.4% (52/103) in Nantou. Analysis of reproductive performance with the 100 youngest RR cows in Tainan, Chunghu, Chiayi, Pingtung and Yulin were conducted. Ages at first calving were 27.0+3.4, 27.2+3.3, 26.2+2.9, 26.8+3.7, and 29.8+3.5 month, respectively. Ages at third calving were 54.1+3.4, 54.2+3.6, 53.9+4.2, 54.6+3.7, and 57.1+3.8 month old with caving interval of 398+54, 392+50, 394+47, 389+46, and 383+43 day. Among of 360 farms, Yulin Oauyoung Farm had the largest number of RR cows with 62.6%(132/211) of RR%. RR cows at Oauyoung Farm had 26.4+3.1 months old at first calving, 4.37+1.38 times of calving, 413+43 days of calving interval, and 72.6+19.8 months old at the highest parity. Wang Breeding Farm, the first certified breeding farm from government, had 42.2% (62/147) of RR% and RR cows had 27.3+3.6 months old at first calving, 5.03+1.88 times of calving, 416+37 days of calving interval, and 83.6+27.1 months old at the highest parity. Ages at drying were 5.29, 5.29, 5.33, 5.25, 5.22, 5.17, 5.09, 5.05, 5.02, 5.12 years old from 1996 to 2005, respectively, with a decrease tendency in age. First calving at 26 month old, three calving within five years old, 383 days of calving interval, and five calving within seven years old could be used for decreasing the age at first calving and shortening calving interval for reproductive registered cows at lifespan of seven years old.
Key Words: Dairy cows, Reproduction registration, Calving interval
  
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