Siopes T D
Department of Poultry Science, North Carolina State University, Raleigh 27695-7608.
Poult Sci. 1992 Dec;71(12):2099-105. doi: 10.3382/ps.0712099.
Two experiments were conducted to evaluate age at photostimulation on subsequent reproductive performance of Large White turkey hens. All hens were exposed to short daylengths [8 h light (L):16 h dark (D)] for a minimum of 8 wk immediately prior to photostimulation with long day-lengths (16L:8D). Photostimulation started at either 24, 26, 28, or 30 wk of age during January and February (Experiment 1) or July and August (Experiment 2). Data were collected for body weight, time to onset of lay, egg production, and livability in both experiments. In addition, egg quality, broodiness, floor egg production, and poult weight data were obtained in Experiment 2. An inverse relationship occurred between initiation of egg production and the age at lighting up to 30 wk of age. However, peak egg production level and the number of eggs produced per hen during the first 20 wk of egg laying were similar among treatment groups in both experiments. The number of soft-shelled or shell-less eggs produced was also similar among treatment groups. Hens photostimulated at 30 wk of age in Experiment 2 laid the heaviest eggs throughout 20 wk of egg production. Poult weight was reduced when hens were photostimulated at 24 or 26 wk of age, but this only occurred in the first 11 wk of lay. Even though Large White hens responded to photostimulation at 24 wk of age, the results do not support advancing the age at photostimulation to 28 wk or earlier.
进行了两项试验，以评估光照刺激时的年龄对大白火鸡母鸡后续繁殖性能的影响。在采用长光照时长（16小时光照：8小时黑暗）进行光照刺激前，所有母鸡均至少8周处于短光照时长（8小时光照：16小时黑暗）环境。光照刺激分别于1月和2月（试验1）或7月和8月（试验2），在24、26、28或30周龄时开始。两项试验均收集了体重、开产时间、产蛋量和存活率数据。此外，试验2还获取了蛋品质、抱窝性、地面产蛋量和雏禽体重数据。在30周龄之前，产蛋开始时间与光照时的年龄呈负相关。然而，在两项试验中，各处理组的产蛋高峰水平以及产蛋前20周每只母鸡的产蛋数相似。各处理组产出的软壳蛋或无壳蛋数量也相似。试验2中在30周龄接受光照刺激的母鸡在整个20周产蛋期内所产的蛋最重。当母鸡在24或26周龄接受光照刺激时，雏禽体重会降低，但这仅发生在产蛋的前11周。尽管大白母鸡在24周龄时对光照刺激有反应，但结果并不支持将光照刺激的年龄提前至28周或更早。
