El-Prollosy Ali, Iraqi Ebtsam, Elsayed Nadia, Khalil Hanaa, El-Saadany Amina, El-Sabrout Karim
Department of Poultry Breeding Research, Animal Production Research Institute, Agriculture Research Center, Giza, Egypt.
Department of Poultry Production, Faculty of Agriculture, Alexandria University, Alexandria, Egypt.
Vet World. 2024 Jun;17(6):1311-1317. doi: 10.14202/vetworld.2024.1311-1317. Epub 2024 Jun 19.
The management of incubation conditions impacts embryonic development, hatchability, and post-hatch performance. This study aimed to examine the effects of thermal manipulation (TM) during embryonic development on roosters' thermotolerance, antioxidant activity, immunity, and semen quality under heat-stress conditions.
1200 fertile eggs were distributed evenly between two groups, each containing three replicates (200 eggs/replicate). The first group (G1) was held in the commercial setter with a consistent temperature of 37.5°C and 55% relative humidity (RH) through the 18-day incubation period, acting as a control, while the second group (G2) experienced these conditions until only the 11 day. The eggs were incubated at 39.5°C with 60% RH for 4 h each day from the 12 to the 18 day. From the 19 to 22 incubation days, both groups maintained a consistent temperature of 37.2°C with a RH of 70%. Two hundred hatched male chicks per treatment group were moved into a closed-system house. All roosters were exposed to a 6-h daily heat challenge with a temperature of 35°C and a humidity of 70% between their 36 and 40 weeks of age.
Roosters of G2 exposed to thermal challenge showed improvements (p ≤ 0.05) in multiple blood biochemical, antioxidant, and immunity markers, including total protein, globulin, aspartate aminotransferase, alanine aminotransferase, triiodothyronine, thyroxine, corticosterone, testosterone, total antioxidant capacity, malondialdehyde, immunoglobulin G, immunoglobulin M, and immunoglobulin A levels. Improved semen quality characteristics, including ejaculate volume, sperm concentration, motility, livability, and quality factor, as well as enhanced thermoregulation in post-hatch cocks, were also achieved (p ≤ 0.05).
To boost antioxidant activity, immunity, thermotolerance, and semen parameters in roosters under heat-stress conditions, TM application during egg incubation, specifically at 12-18 days, is recommended.
孵化条件的管理会影响胚胎发育、孵化率及出壳后性能。本研究旨在探究胚胎发育期间热调控（TM）对热应激条件下公鸡耐热性、抗氧化活性、免疫力及精液品质的影响。
1200枚受精蛋平均分配至两组，每组包含三个重复（200枚蛋/重复）。第一组（G1）在商业孵化器中于18天的孵化期内保持37.5°C的恒定温度和55%的相对湿度（RH），作为对照，而第二组（G2）在11日龄前经历这些条件。从第12天至第18天，每天将蛋在39.5°C、60%RH的条件下孵化4小时。从第19天至第22天孵化期，两组均保持37.2°C的恒定温度和70%的RH。每个处理组的200只出壳雄性雏鸡被转移至封闭系统鸡舍。所有公鸡在36至40周龄期间每天接受6小时、温度为35°C、湿度为70%的热应激挑战。
经历热应激挑战的G2组公鸡在多种血液生化、抗氧化和免疫指标方面有所改善（p≤0.05），包括总蛋白、球蛋白、天冬氨酸转氨酶、丙氨酸转氨酶、三碘甲状腺原氨酸、甲状腺素、皮质酮、睾酮、总抗氧化能力、丙二醛、免疫球蛋白G、免疫球蛋白M和免疫球蛋白A水平。还实现了精液品质特征的改善，包括射精量、精子浓度、活力、存活率和品质因子，以及出壳后公鸡体温调节能力的增强（p≤0.）。
为提高热应激条件下公鸡的抗氧化活性、免疫力、耐热性和精液参数，建议在蛋孵化期间，特别是在12至18天应用TM。
