Khani Kambiz, Ghazanfari Shokoufe, Najafi Abouzar
Department of Livestock and Poultry Sciences, Faculty of Agricultural Technology (Aburaihan), University of Tehran, Pakdasht, Tehran, Iran.
Vet Anim Sci. 2025 Feb 28;27:100435. doi: 10.1016/j.vas.2025.100435. eCollection 2025 Mar.
This study explored the impact of rosemary extract and ascorbic acid sprays on eggs incubated at high temperatures, focusing on embryonic development, hatchability, and chick physiology. A total of 1,200 eggs were divided into four treatment groups: distilled water, rosemary extract, ascorbic acid, and no spray, under normal and heat stress conditions. Ascorbic acid under heat stress reduced embryo length by day 18. Using 30 g/L ascorbic acid increased egg weight, decreased water loss, reduced embryonic weight, and altered yolk sac to embryo weight ratio ( < 0.05). It also extended incubation time and increased embryonic mortality by day 21, negatively affecting hatchability ( < 0.05). Heat stress raised yolk sac weight and lowered cloacal temperature in chicks. Ascorbic acid increased yolk sac weight but resulted in shorter chicks at hatch. Rosemary extract and distilled water under heat stress increased red blood cell counts, while distilled water at normal temperatures had the highest hematocrit percentage ( < 0.05). Untreated eggs showed higher white blood cell counts and heterophil-to-lymphocyte ratios in chicks. Within 40 h post-hatch, ascorbic acid reduced chick weight but increased yolk sac metrics. Rosemary extract decreased cloacal and body surface temperatures ( < 0.05). By week's end, ascorbic acid reduced chick length, while heat stress improved chick weights and feed conversion ratios during broiler rearing ( < 0.05). In conclusion, rosemary extract and ascorbic acid significantly influence embryonic development and physiological responses. Ascorbic acid notably reduced hatchability and increased embryonic mortality under heat stress, highlighting its critical effects.
本研究探讨了迷迭香提取物和抗坏血酸喷雾对高温孵化鸡蛋的影响，重点关注胚胎发育、孵化率和雏鸡生理状况。在正常和热应激条件下，将总共1200枚鸡蛋分为四个处理组：蒸馏水、迷迭香提取物、抗坏血酸和不喷雾组。热应激条件下的抗坏血酸使第18天的胚胎长度缩短。使用30 g/L抗坏血酸可增加蛋重、减少水分流失、降低胚胎重量，并改变卵黄囊与胚胎重量比（<0.05）。它还延长了孵化时间，并在第21天增加了胚胎死亡率，对孵化率产生负面影响（<0.05）。热应激提高了雏鸡的卵黄囊重量并降低了泄殖腔温度。抗坏血酸增加了卵黄囊重量，但导致雏鸡出壳时体型较短。热应激条件下的迷迭香提取物和蒸馏水增加了红细胞计数，而常温下的蒸馏水具有最高的血细胞比容百分比（<0.05）。未处理的鸡蛋在雏鸡中显示出更高的白细胞计数和异嗜性粒细胞与淋巴细胞比率。出壳后40小时内，抗坏血酸降低了雏鸡体重，但增加了卵黄囊指标。迷迭香提取物降低了泄殖腔和体表温度（<0.05）。到周末时，抗坏血酸降低了雏鸡长度，而热应激提高了肉鸡饲养期间的雏鸡体重和饲料转化率（<0.05）。总之，迷迭香提取物和抗坏血酸显著影响胚胎发育和生理反应。抗坏血酸在热应激下显著降低了孵化率并增加了胚胎死亡率，突出了其关键影响。
