Faculty of Agriculture, Department of Animal Science, Aydın Adnan Menderes University, Aydın, Türkiye.
Çine Vocational High School, Aydın Adnan Menderes University, Çine, Aydın, Türkiye.
Trop Anim Health Prod. 2024 Oct 8;56(8):330. doi: 10.1007/s11250-024-04119-3.
This study investigated the effects of in ovo betaine and thermal manipulation during incubation on growth performance, and some immune parameters of broilers under cyclic heat stress (CHS). Eggs were divided into 5 groups and incubated at 1) 37.8 °C and 60% relative humidity (Control incubation and not-injected, CI); 2) eggs were incubated at CI and in ovo betaine injected into yolk sac on d 11 (E11) (CI + In ovo); 3) eggs were exposed to 38.8 °C for 8 h between 10 and 18d of incubation (heat acclimation, HA); 4) eggs were incubated at HA and in ovo betaine applied (HA + In ovo); 5) positive control: eggs were incubated at CI and injected with saline. Hatched chicks were raised under standard management conditions until 21 d, between 21 and 42 d half of the chickens in each incubation treatment were kept either at optimum (OPT) or at CHS. In ovo and HA did not affect hatching performance. In ovo increased thymus and spleen weights of chicks. Serum IgG was higher in HA + In ovo chicks. From d 7 to 21, in ovo chicks were heavier body weights, consumed more feed, and better feed conversion than those from CI. The body weights of HA chickens were similar in OPT and CHS on d 28 and 35. CHS reduced the body weight of CI chickens which was compatible with their feed consumption. Moreover, feed intake of HA + In ovo chickens exposed to CHS was higher than those not injected indicating that HA + In ovo enhanced thermoregulation of chickens under CHS.
本研究调查了在孵化过程中胚内甜菜碱和热处理对循环热应激（CHS）下肉鸡生长性能和一些免疫参数的影响。鸡蛋分为 5 组，分别在 1）37.8°C 和 60%相对湿度（对照孵化和未注射，CI）；2）在 CI 下孵化，第 11 天（E11）向蛋黄囊内注射胚内甜菜碱（CI+In ovo）；3）孵化期间在 10 至 18 天暴露于 38.8°C 8 小时（热适应，HA）；4）在 HA 下孵化并应用胚内甜菜碱（HA+In ovo）；5）阳性对照：在 CI 下孵化并注射生理盐水。孵化后的小鸡在标准管理条件下饲养至 21 天，在每个孵化处理中，21 至 42 天期间，一半的小鸡分别保持在最佳（OPT）或 CHS 下。胚内和 HA 不影响孵化性能。胚内增加了雏鸡的胸腺和脾脏重量。HA+In ovo 雏鸡的血清 IgG 更高。从第 7 天到第 21 天，胚内雏鸡的体重、采食量和饲料转化率均优于 CI 雏鸡。HA 雏鸡在 OPT 和 CHS 下在第 28 天和第 35 天的体重相似。CHS 降低了 CI 雏鸡的体重，与它们的饲料消耗相匹配。此外，暴露于 CHS 的 HA+In ovo 雏鸡的采食量高于未注射的雏鸡，表明 HA+In ovo 增强了 CHS 下鸡的体温调节能力。
