Eitan Y, Soller M
Department of Genetics, The Silberman Life Sciences Institute, The Hebrew University of Jerusalem, Israel.
Poult Sci. 2001 Oct;80(10):1397-405. doi: 10.1093/ps/80.10.1397.
The effects of feed restriction and photoperiod on body weight (WTSXM) and age (ASXM) at onset of mature semen production in males and onset of lay in females of a broiler female line were examined. Feeding treatments were as follows: ad libitum (AL) and quantitative feed restriction (QR). Photoperiod treatments were as follows: open shed (OS), in which the chicks were reared under naturally increasing daylight with supplemental light; dark room (DR), in which chicks were reared under short days, gradually increasing from 6 h of light (L) to 11.5L; and dark room to open shed (DR-OS), in which chicks reared under short days in the dark room were transferred to the open shed at 149 d. Treatment effects were similar in direction in males and females, suggesting similar control of entry into reproduction of the two sexes, although within a given treatment, males matured earlier than females. Effects of feeding and photoperiod treatments were additive. Relative to QR, the AL feeding treatment increased WTSXM by 832 g for males and 1,089 g for females; ASXM was decreased by 15.8 d for males and 9.3 d for females. Relative to OS, the DR photoperiod increased WTSXM by 591 g for males and 513 g for females; ASXM was increased by 17.5 d for males and 26.8 d for females. The DR-OS photoperiod increased WTSXM by 86 and 169 g for males and females, respectively; ASXM was increased by 6.1 d and 4.9 d, respectively. Under DR, the delay in onset of sexual maturity caused by QR was not due to failure to reach threshold body weight or age and, hence, appears to have resulted from the feed restriction itself. A similar delay for QR was found under OS but might have been due to failure to reach threshold body weight. It is speculated that the delay in onset of sexual maturity caused by feed restriction may be an ecological adaptation or, alternatively, a result of nutritional imbalance.
研究了限饲和光照周期对肉种鸡母系雄性开始产生成熟精液时的体重（WTSXM）和年龄（ASXM）以及雌性开始产蛋时的体重和年龄的影响。饲养处理如下：自由采食（AL）和定量限饲（QR）。光照周期处理如下：开放式鸡舍（OS），即雏鸡在自然增加的光照并补充光照的条件下饲养；暗室（DR），即雏鸡在短日照条件下饲养，光照时间从6小时逐渐增加到11.5小时；以及暗室转开放式鸡舍（DR - OS），即暗室中短日照饲养的雏鸡在149日龄时转移到开放式鸡舍。雄性和雌性的处理效果在方向上相似，这表明两性进入繁殖期的控制方式相似，尽管在给定处理中，雄性比雌性成熟更早。饲养和光照周期处理的效果是累加的。相对于QR，AL饲养处理使雄性的WTSXM增加了832克，雌性增加了1089克；雄性的ASXM减少了15.8天，雌性减少了9.3天。相对于OS，DR光照周期使雄性的WTSXM增加了591克，雌性增加了513克；雄性的ASXM增加了17.5天，雌性增加了26.8天。DR - OS光照周期使雄性和雌性的WTSXM分别增加了86克和169克；ASXM分别增加了6.1天和4.9天。在DR条件下，QR导致的性成熟开始延迟并非由于未达到阈值体重或年龄，因此，似乎是限饲本身导致的。在OS条件下也发现了QR导致的类似延迟，但可能是由于未达到阈值体重。据推测，限饲导致的性成熟开始延迟可能是一种生态适应，或者是营养失衡的结果。
