SUMMARY Double-yolked (DY) eggs are a rare phenomenon in domestic poultry and game birds, generally ~1-2% of the eggs are DY over the laying cycle. The production of such eggs is influenced by several factors from which the most important ones include genetics, selection for multiple ovulations, female age, light exposure and nutrition. It is known that higher body weight is the result of selection, and has been correlated to the increase in multiple ovulations. The increased incidence of DY eggs is a consequence of the multiple ovulations, which are more prevalent in the first 10 weeks of laying, when up to 25% of follicles develop as pairs, because the regulation of follicle maturation and ovulation is not fully established. This regulation involves endocrinological and physiological changes, which are mediated by light, and management during rearing and laying is crucial to reduce DY eggs. Restricted feeding (~50% daily feed intake of ad libitum) results in decreased follicle production and multiple ovulations, hence reduces DY egg production. Feed should contain less protein (<16%) to control body weight gain. However, if DY egg production is the goal, birds should be fed ad libitum with high protein (>16%) to achieve higher body weights. Furthermore, applying photostimulation early (6–12 weeks of age for domestic fowl), increasing photoperiod to 13–16 hours of light and light intensity to (>80 lux).

中文翻译：

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影响双黄蛋产量的因素

总结 双黄 (DY) 鸡蛋在家禽和野禽中是一种罕见的现象，在产蛋周期中，通常约 1-2% 的鸡蛋是 DY。此类鸡蛋的生产受多种因素的影响，其中最重要的因素包括遗传、多次排卵的选择、女性年龄、光照和营养。众所周知，较高的体重是选择的结果，并且与多次排卵的增加有关。DY 卵子发生率增加是多次排卵的结果，在产卵的前 10 周更为普遍，此时多达 25% 的卵泡成对发育，因为卵泡成熟和排卵的调节尚未完全建立。这种调节涉及内分泌和生理变化，这些变化是由光介导的，饲养和产蛋期间的管理对于减少 DY 鸡蛋至关重要。限制喂养（约 50% 的每日采食量）会导致卵泡产量减少和多次排卵，从而降低 DY 产蛋量。饲料应含有较少的蛋白质 (<16%) 以控制体重增加。然而，如果以 DY 产蛋为目标，则应随意饲喂高蛋白 (>16%) 的鸡以达到更高的体重。此外，尽早应用光刺激（家禽为 6-12 周龄），将光周期增加到 13-16 小时，光强度增加到（>80 lux）。16%) 以控制体重增加。然而，如果以 DY 产蛋为目标，则应随意饲喂高蛋白 (>16%) 的鸡以达到更高的体重。此外，尽早应用光刺激（家禽为 6-12 周龄），将光周期增加到 13-16 小时，光强度增加到（>80 lux）。16%) 以控制体重增加。然而，如果以 DY 产蛋为目标，则应随意饲喂高蛋白 (>16%) 的鸡以达到更高的体重。此外，尽早应用光刺激（家禽为 6-12 周龄），将光周期增加到 13-16 小时，光强度增加到（>80 lux）。