Livestock Experiment Station, Akita Prefectural Agriculture, Forestry and Fisheries Research Center, Jin-guji, Daisen 019-1701, Akita, Japan.
Poult Sci. 2011 Aug;90(8):1852-7. doi: 10.3382/ps.2010-01270.
We developed a new tool for testectomy and investigated the efficiency with regard to caponizing time and growth performance in Hinai-jidori chickens, a popular breed of chicken in Japan. Hinai-jidori chicks were divided into 2-, 4-, and 8-wk caponized groups and an intact male group (20 birds/group) at 2 wk of age and were raised until 26 wk of age. The testes of the male chicks caponized at 8 wk of age were surgically removed from both sides using a Japanese traditional tool, whereas those of male chicks caponized at 2 and 4 wk of age were surgically removed from only one side using the new tool. Using the traditional method, caponization of an 8-wk-old chick was achieved in 324.6 s (5 min 24 s), whereas using the new method, caponization of 2- and 4-wk-old chicks was achieved in only 35.9 and 28.4 s, respectively. Moreover, at 10 and 18 wk of age, the chicks caponized at 4 wk of age were significantly heavier than the chicks caponized at 8 wk of age. The data suggest that the decrease in the daily weight gain caused by caponization at a younger age was less than that at an older age. We concluded that early caponization shortens the caponizing time significantly and improves the decrease in the daily weight gain after caponization, thereby enabling efficient capon production from slow-growing meat-type chickens at early stages of development.
我们开发了一种新的去势工具，并研究了其在日本流行的鸡品种——日野鸡去势时间和生长性能方面的效率。在 2 周龄时，将日野鸡雏鸡分为 2 周、4 周和 8 周去势组和完整雄性组（每组 20 只），并饲养至 26 周龄。8 周龄雄性雏鸡的睾丸使用日本传统工具从两侧进行手术切除，而 2 周和 4 周龄雄性雏鸡的睾丸仅使用新工具从一侧进行手术切除。使用传统方法，8 周龄雏鸡的去势时间为 324.6 秒（5 分 24 秒），而使用新方法，2 周和 4 周龄雏鸡的去势时间分别仅为 35.9 秒和 28.4 秒。此外，在 10 周和 18 周龄时，4 周龄去势的雏鸡比 8 周龄去势的雏鸡明显更重。数据表明，在较小年龄进行去势导致的日增重减少量小于较大年龄进行去势的情况。我们得出结论，早期去势可以显著缩短去势时间，并改善去势后日增重的减少，从而使生长缓慢的肉用型鸡在早期发育阶段能够高效地进行去势生产。
