Mekasha Y, Tegegne A, Abera A, Rodriguez-Martinez H
Division of Reproduction, Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Science (SLU), Ullsväg, 14C Sweden.
Reprod Domest Anim. 2008 Apr;43(2):196-206. doi: 10.1111/j.1439-0531.2007.00877.x.
Five tropically adapted buck breeds extensively managed in Ethiopia were studied to determine possible effects of breed and age on body size and testicular traits. In all, 177 bucks were selected following stratified random sampling, and evaluated in three age groups: <14 months (young), 14-19.5 months (intermediate) and 19.6-24 months (old). The breeds studied were Arsi-Bale (AB; N = 35), Central Highlands (CH; N = 33), Afar (N = 35), Boran (N = 36) and Woito-Guji (WG; N = 38). In all the three age groups, Boran and CH bucks were the heaviest (p < 0.05), Afar were the lightest, and AB and WG were in between. The highest body weight (BW) was achieved in the intermediate age group for Afar, but in the oldest age group for the other breeds. In the youngest age group, scrotal circumference (SC) was the widest (p < 0.05) for Boran and CH and the narrowest for Afar, AB and WG, while in the intermediate and the oldest age groups, Boran showed the widest SC. Boran, WG and CH had higher (p < 0.05) testicular weight (TW) than Afar and AB in the youngest age group. Boran retained the highest (p < 0.05) TW in the intermediate and the oldest age groups, while in the oldest age group WG and AB medium TW and Afar had the lowest TW. However, Afar had the highest TW expressed as percentage of BW. SC was well correlated with TW (p < 0.001; r = 0.74) and BW (p < 0.001; r = 0.61), indicating a linear, positive association between BW and TW (p < 0.001; r = 0.51). In conclusion, body size and testicular traits of Ethiopian bucks under an extensive management system are influenced differently by breed and age group.
对埃塞俄比亚广泛养殖的五个热带适应型公羊品种进行了研究，以确定品种和年龄对公羊体型和睾丸性状的可能影响。通过分层随机抽样共选取了177只公羊，并分为三个年龄组进行评估：<14个月（幼年）、14 - 19.5个月（中年）和19.6 - 24个月（老年）。所研究的品种有阿尔西 - 巴莱（AB；N = 35）、中部高地（CH；N = 33）、阿法尔（N = 35）、博拉纳（N = 36）和沃伊托 - 古吉（WG；N = 38）。在所有三个年龄组中，博拉纳和CH公羊最重（p < 0.05），阿法尔最轻，AB和WG介于两者之间。阿法尔在中年年龄组达到最高体重（BW），而其他品种在老年年龄组达到最高体重。在最年轻年龄组，博拉纳和CH的阴囊周长（SC）最宽（p < 0.05），阿法尔、AB和WG最窄，而在中年和老年年龄组，博拉纳的SC最宽。在最年轻年龄组，博拉纳、WG和CH的睾丸重量（TW）高于阿法尔和AB（p < 0.05）。在中年和老年年龄组，博拉纳的TW最高（p < 0.05），而在老年年龄组，WG和AB的TW中等，阿法尔的TW最低。然而，阿法尔的TW占BW的百分比最高。SC与TW（p < 0.001；r = 0.74）和BW（p < 0.001；r = 0.61）高度相关，表明BW和TW之间存在线性正相关（p < 0.001；r = 0.51）。总之，在广泛养殖系统下，埃塞俄比亚公羊的体型和睾丸性状受品种和年龄组的影响不同。
