Department of Animal Science, Faculty of Agriculture, Damascus University, Damascus 30621, Syria.
Anim Reprod Sci. 2013 Sep;141(1-2):80-5. doi: 10.1016/j.anireprosci.2013.07.005. Epub 2013 Jul 23.
Two experiments were conducted to determine oviposition pattern and the effect of oviposition time on egg weight, body weight at hatch, and sex ratio of hatched chickens. In Experiment 1, eggs were collected from young and mid-age broiler flocks for 6 consecutive days at hourly intervals between 0400 and 2000h. In Experiment 2, eggs were categorized to represent eggs where oviposition occurred early, middle and late in the clutch (later in the day). These eggs were incubated to determine body weight at hatch and sex ratio of hatched chickens relative to oviposition time. Time of oviposition was affected by age. For the young flock, the percentage of ovipositions occurring before the 1100h was 79%. In contrast to the young flock, the percentage of ovipositions occurring before the 1100h in the mid-age flock was less (68%; P<0.01). Furthermore, for the mid-age flock, the percentage of ovipositions occurring from 1200 to 1700h was greater (P<0.01) at 32% in comparison to that of the younger flock at 21%. Egg weights when oviposition occurred earlier in the day were greater (P<0.01) than when oviposition occurred in the middle and later in the clutch (later in the day). Similarly, body weight at hatch of chicks from eggs where oviposition occurred earlier in the day was heavier than when oviposition occurred in the middle and later in the clutch (later in the day).With hatching of the eggs from hens when ovipositions occurred earlier in the day, there was a female sex bias. Differences in egg weights, body weight at hatch, and sex ratio due to time of oviposition suggest that oviposition time together with incubation conditions should be considered for obtaining greater uniformity and growth of chickens.
进行了两项实验，以确定产卵模式以及产卵时间对鸡蛋重量、孵化时体重和孵化小鸡性别比例的影响。在实验 1 中，连续 6 天，在 04:00 至 20:00 之间每小时收集一次来自年轻和中年肉鸡群的鸡蛋。在实验 2 中，将鸡蛋分类为代表产蛋早、中、晚期（当天较晚时间）的鸡蛋。对这些鸡蛋进行孵化，以确定孵化时体重和孵化小鸡的性别比例与产卵时间的关系。产卵时间受年龄的影响。对于年轻的鸡群，11:00 前产卵的比例为 79%。与年轻鸡群相比，中年鸡群 11:00 前产卵的比例较低（68%；P<0.01）。此外，对于中年鸡群，12:00 至 17:00 之间产卵的比例较大（P<0.01），为 32%，而年轻鸡群为 21%。当天早些时候产卵的鸡蛋重量较大（P<0.01），而当天中晚期产卵的鸡蛋重量较小（当天较晚时间）。同样，当天早些时候产卵的鸡蛋孵化的小鸡的孵化时体重也比当天中晚期产卵的鸡蛋孵化的小鸡重（当天较晚时间）。当天早些时候产卵的母鸡所产鸡蛋孵化时，存在雌性性别偏向。由于产卵时间的不同，鸡蛋重量、孵化时体重和性别比例存在差异，这表明为了获得更大的均匀性和鸡的生长，应考虑产卵时间和孵化条件。
