Nøddegaard F, Talbot R T, Sharp P J
Danish Institute of Agricultural Sciences, Research Center Foulum, Tjele.
Poult Sci. 2000 May;79(5):778-83. doi: 10.1093/ps/79.5.778.
The aim of the study was to establish, in contemporary broiler breeders, whether delayed photostimulation at 313 d results in a reproductive response similar to that after photostimulation at 134 d (standard practice). The standard lighting program was compared with a novel program in which daily hours of light were reduced to 3 h during rearing and kept at 3 h until photostimulation at 264 d (8 h) or at 313 d (16 h). This experiment was done with hens fed ad libitum or feed-restricted hens. In photostimulated and nonphotostimulated hens, feed restriction delayed the onset of egg production and enhanced the subsequent rate of laying. Standard photostimulation advanced the onset of lay and increased the subsequent rate of lay in hens fed ad libitum and feed-restricted hens. Delayed photostimulation of hens did not impair the photoinduced increase in the concentration of plasma luteinizing hormone (LH) or egg production. Delayed photostimulation in cockerels failed to stimulate LH secretion. Unexpectedly, for feed-restricted hens, transfer from 3 to 8 h light/d at 264 d resulted in an increased in plasma LH and increased egg production. A similar increase in plasma LH was observed for cockerels subjected to the same lighting treatment. We concluded that, in broiler breeder hens, the reproductive response to photostimulation is not impaired if photostimulation is delayed for up to 313 d. Cockerels may not respond well to delayed photostimulation.
本研究的目的是确定在当代肉种鸡中，313日龄时延迟光照刺激是否会产生与134日龄时光照刺激（标准做法）相似的繁殖反应。将标准光照程序与一种新程序进行比较，在新程序中，饲养期间每日光照时间减少到3小时，并保持在3小时，直到264日龄（8小时）或313日龄（16小时）进行光照刺激。本实验对自由采食母鸡或限饲母鸡进行。在光照刺激和未光照刺激的母鸡中，限饲会延迟产蛋开始时间并提高随后的产蛋率。标准光照刺激会提前产蛋开始时间，并提高自由采食母鸡和限饲母鸡随后的产蛋率。母鸡延迟光照刺激不会损害光诱导的血浆促黄体生成素（LH）浓度增加或产蛋量。公鸡延迟光照刺激未能刺激LH分泌。出乎意料的是，对于限饲母鸡，在264日龄时从每天3小时光照增加到8小时会导致血浆LH增加和产蛋量增加。对接受相同光照处理的公鸡也观察到了类似的血浆LH增加。我们得出结论，在肉种鸡母鸡中，如果光照刺激延迟至313日龄，对光照刺激的繁殖反应不会受到损害。公鸡可能对延迟光照刺激反应不佳。
