李世昌 吳明哲 張秀鑾 黃瓊姿
雷克斯兔種四個毛色品系於1990年至1996年間的產仔胎數計有2114胎，分別有海狸色594胎、錦企拉色509胎、寶藍色501胎和白色510胎。四個毛色品系母兔初產日齡之平均與標準機差分別為243±3 (221頭)、285±4 (140頭)、262±4 (158頭)和257±4天 (137頭)，品系間差異顯著（P<0.05)。每胎仔兔數分別為5.52±.09、5.32±.10、5.40±.10和5.32±.10頭，品系間差異並不顯著。每胎活仔數的百分比在錦企拉色品系為90.2±1.3%，顯著地多於寶藍色品系的85.5±1.2%，但僅略高於白色品系(88.4±1.3%)和海狸色品系(87.2±1.1%)。仔兔於四週齡離乳時之育成率，以白色品系為最高，有67.8±2.0%，其次為錦企拉色品系(65.4±2.0%)和海狸色品系(62.0±1.7%)，最低者為寶藍色品系(54.1±1.9%)，品系間差異顯著（P<0.05)。整體而言，不同毛色的雷克斯兔之仔兔育成率均不及70%。
COMPARISON ON LITTER TRAITS AMONG VARIETIES OF
COLOR IN REX RABBITS
S. C. Lee, M. C. Wu, H. L. Chang and C. T. Huang
Taiwan Livestock Research Institute
Rex breed of rabbits consists of Castor, Chinchilla, Opal and White fur color varieties were studied for comparison on litter traits collected from 1990 to 1996. Data of 2114 litters was analyzed, which included 594, 509, 501 and 510 litters produced by Castor, Chinchilla, Opal and White does, respectively. Mean and standard error for the age at first parity of does in the above four color varieties were 243+3 (N=221), 285+4 (N=140), 262+4 (N=158) and 257+4 (N=137) days, respectively and differences on ages among varieties were significant (P<0.05). Litter sizes of the above four varieties were 5.52+0.09, 5.32+0.10, 5.40+0.10 and 5.32+0.10 with no variety difference. The percentage of live born per litter in Chinchilla Rex was 90.2+1.3%, which was significantly higher than the 85.5+1.2% of Opal Rex. But it was only slightly higher than that of 88.4+1.3% in White Rex and 87.2+1.1% in Castor Rex. The survival rates of pups per litter at weaning were significantly different (P<0.05) among color varieties when pups were weaned at four weeks old. The highest survival rate of pups at weaning was 67.8+2.0% in White Rex, and less in Chinchilla Rex (65.4+2.0%) and Castor Rex (62.0+1.7%). The lowest rate of pups at weaning was 54.1+1.9% in Opal Rex. Overall, the survival rate of pups at weaning was not more than 70% among varieties of Rex breed.
Key Words: Rex rabbit, Fur color, Litter traits.