孵化温度是影响雏鸡胚胎发育和品质的重要环境因素。胚胎阶段的代谢,特别是肝脏脂质代谢,对家禽的生长发育至关重要。本研究旨在探讨胚胎热操作与高(TMH,39.5°C,65%RH,8小时/天)和低(TML,20°C,65%RH,1h/d)在8-15胚龄期间的温度对蛋鸡的孵化性能和肝脏脂质代谢的影响。此外,通过短期喂养试验评估TM效应的持续时间.结果表明,TMH加速了孵化过程,而不会显着影响孵化率和生长性能。相比之下,TML延迟了孵化时间,并显着降低了孵化率和雏鸡品质。孵化后,相对于体重(BW)和无蛋黄体重(YFBM),TML还增加残余蛋黄重量并降低相对肝脏重量。此外,肝脏中的脂滴用油红O染色,进一步检测肝脏和血清中的脂质含量。TMH对肝脏和血清中甘油三酯(TG)和总胆固醇(TCHO)含量无显著影响,但上调了脂肪生成相关基因ACC的表达,Fas,和Fatp1与TML组相比。相反,TML显著降低肝脏TG含量,增强脂蛋白脂肪酶(LPL)活性,并促进脂质氧化相关基因CPT-1、PGC-1α、和PPARα。7岁时,TMH组肝脏LPL活性显著增高。然而,TML组肝脏TG、TCHO含量及脂质代谢相关基因表达无明显变化。总的来说,这些结果表明,胚胎热操作改变了蛋鸡的孵化性能和肝脏脂质代谢。TML通过增加肝脏脂质氧化能力来降低TG含量。然而,这种效果不会持久,随着TM的影响随着雏鸡的发育而减弱。
Incubation temperature is a crucial environmental factor affecting embryonic development and chick quality. Metabolism during the embryonic stage, particularly liver lipid metabolism, is essential for the growth and development of poultry. This study aimed to investigate the effects of embryo thermal manipulation with high (TMH, 39.5°C, 65% RH, 8 h/d) and low (TML, 20°C, 65% RH, 1 h/d) temperatures during 8-15th embryonic age on
hatching performance and liver lipid metabolism in layer chicks. Additionally, the duration of TM effects was evaluated through a short-term feeding trial. The results indicated that TMH accelerated the
hatching process without significantly affecting hatchability and growth performance. In contrast, TML delayed
hatching time and significantly reduced hatchability and chick quality. After
hatching, TML also increased residual yolk weight and reduced the relative liver weight in relation to body weight (BW) and yolk-free body mass (YFBM). Moreover, lipid droplets in the liver were stained with Oil Red O, and the lipid content in the liver and serum was further detected. TMH had no significant impact on triglyceride (TG) and total cholesterol (TCHO) content in the liver and serum, but upregulated the expression of lipogenesis-related genes ACC, Fas, and Fatp1 compared to the TML group. Conversely, TML significantly reduced liver TG content, enhanced lipoprotein lipase (LPL) activity, and promoted the expression of lipid oxidation-related genes CPT-1, PGC-1α, and PPARα. At 7 d of age, liver LPL activity was significantly increased in the TMH group. However, there were no significant changes in the content of TG and TCHO in the liver and the expression of lipid metabolism-related genes in the TML group. Overall, these results indicate that embryonic thermal manipulation alters
hatching performance and liver lipid metabolism in layer chicks. TML reduces TG content by increasing liver lipid oxidation capacity. However, this effect is not long-lasting, as the influence of TM diminishes as the chicks develop.