The blastoderm, which represents the fertilized germinal disc, undergoes cellular events of division, differentiation and organization to achieve embryonic development in chickens. In this study, blastodermal cell counts and hatching performance of Marshall^® broiler breeders as influenced by flock age and egg storage were investigated. A total of 1,520 eggs from the flock ages, 43 weeks (younger) and 65 weeks (older), under similar management and nutritional regime were incubated after storage at 16°C with 75% relative humidity for duration of 0 (fresh eggs), 4, 7 and 10 days. Results show that total blastodermal cell counts (BCC) for both ages declined with increasing storage duration, with a sharp regression at 4d storage from younger breeders. Higher percentages of fertility and hatchability were recorded for younger breeders compared to older breeders. Percentage hatchability was statistically similar (p > .05) for both 43 weeks and 65 weeks old broiler breeders under 0, 4 and 7d storage except at 10d storage which was lower for older breeders. Chick lengths were longer with younger breeders whereas older breeders had heavier chick weights. Also, significant associations were found between BCC and fertility, hatchability of fertile eggs and chick weights, respectively, under different conditions. These results indicate that fresh eggs (0d) and short‐term stored eggs (4‐ and 7 d) from 43 weeks old breeders had higher total blastodermal cell counts, fertility, hatchability and increased chick lengths compared to 65 week old breeders which produced heavier chicks. Therefore, egg storage longer than 7 days especially from older breeders resulted in modifications to the blastoderm which subsequently affected fertility, hatchability, embryo liveability and hatched chick quality. Also, detection of BCC in fertile eggs can serve as a predictive tool in fertility and hatchability evaluations.

中文翻译：

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不同鸡群年龄的 Marshall® 肉种鸡在种蛋储存期间的胚盘发育、孵化率和雏鸡质量。

代表受精生发盘的胚盘经历分裂、分化和组织的细胞事件以实现鸡的胚胎发育。在本研究中，Marshall ^{® 的}胚盘细胞计数和孵化性能对受鸡群日龄和蛋储存影响的肉鸡种鸡进行了调查。来自 43 周龄（幼龄）和 65 周龄（幼龄）的总共 1,520 枚鸡蛋，在类似的管理和营养方案下，在 16°C 和 75% 的相对湿度下储存 0（新鲜鸡蛋）持续时间后孵化， 4、7 和 10 天。结果表明，两个年龄段的总胚盘细胞计数 (BCC) 随着储存时间的增加而下降，年轻种鸡在第 4 天的储存时急剧回归。与年长的种鸡相比，年轻种鸡的受精率和孵化率更高。百分比孵化率在统计上相似 ( p > .05) 对于 43 周龄和 65 周龄的肉鸡种鸡而言，在 0、4 和 7 天的贮藏期内，除了 10 天的贮藏期外，年龄较大的种鸡较低。年轻种鸡的雏鸡长度较长，而年长的种鸡的雏鸡体重较重。此外，在不同条件下，BCC 与受精卵的孵化率和雏鸡体重之间分别存在显着关联。这些结果表明，与 65 周龄种鸡相比，43 周龄种鸡的新鲜种蛋 (0 天) 和短期储存种蛋 (4 天和 7 天) 具有更高的总胚盘细胞计数、生育力、孵化率和增加的雏鸡长度。小鸡。因此，蛋储存超过 7 天，尤其是来自较老的种鸡，会导致胚盘发生变化，从而影响生育力、孵化率、胚胎存活率和孵化雏鸡质量。此外，受精卵中 BCC 的检测可以作为生育力和孵化率评估的预测工具。