雷克斯種母兔之繁殖年限

吳明哲 李世昌 張秀鑾 黃瓊姿

台灣省畜產試驗所

雷克斯兔種之新母兔於五月齡被選留為種用母兔後，就移入懸吊式鐵線分娩欄內，欄的長寬高為45×90×36cm，離地面有55cm。自1990年至1995年間出生的母兔，計有822頭被選留為種用母兔，分別有261頭海狸色、167頭錦企拉色、195頭寶藍色和199頭白色等品系之母兔。不分毛色品系時，雷克斯母兔的第一產至第十產的分娩日齡之平均依序為262、329、405、479、557、633、708、784、856和907天。四個品系種兔的死亡率分別為36.40、13.77、17.95和27.14%。當把死亡種兔分類為未分娩過的和經產的，四個毛色品系未分娩過的母兔之死亡日齡平均分別為240、348、268和275天；而經產母兔死亡日齡之平均分別為397、481、467和464天。四個品系經產母兔的淘汰日齡之平均為474、602、504和514天就予以淘汰。不同毛色母兔群中的最多產次的母兔分別有生產16、15、13和19胎的母兔。母兔分娩日齡最老者有1447天，表示雷克斯種母兔繁殖年限可達4年之久。

關鍵語：雷克斯兔、毛色、繁殖年限。

REPRODUCTIVE LIFE SPAN OF RABBIT DOES OF REX BREED

M. C. Wu, S. C. Lee, H. L. Chang and C. T. Huang

Taiwan Livestock Research Institute

Young does of Rex rabbits at five months of age were selected as breeding stocks and then they were raised individually in a net box (45x90x36cm) which was hanged 55cm above the floor. Data analysis was based upon their birth year from 1990 to 1995, 822 Rex does consisting of 261 Castor, 167 Chinchilla, 195 Opal and 199 White fur color varieties were traced for mortality, ages at death, culling and parturition, and number of parity. Regardless of color varieties Rex rabbit does gave births from first to tenth parity at 262, 329, 405, 479, 557, 633, 708, 784, 856 and 907 days of age. Percentages of Mortality in four varieties of fur color described above were 36.40, 13.77, 17.95 and 27.14%, respectively. When dead does were classified into the no-progeny group and the progeny-yes group. Average age at death of rabbit doe for the above four varieties were 240, 348, 268 and 275 days old, respectively, in the no-progeny group; whereas age at death were 397, 481, 467 and 464 days old in the progeny-yes group. For those of culled does they were culled at 474, 602, 504 and 514 days of age in average. The highest numbers of parities of does in the above four varieties were 16, 15, 13 and 19, respectively. The oldest doe at parturition among all does was 1447 days of age that it indicated the reproductive life span of Rex doe could be four years long.

Key Words: Rex rabbit, Fur color, Reproductive life span.