Effects of prenatal auditory stimulation on physiological stress and neurotransmitter levels in developing embryos and day-old ducklings

Abstract

Objective: The objective of the study was to determine the effects of prenatal auditory stimulation (PAS) on serum concentrations of heat shock protein 70 (HSP70), ceruloplasmin (CPN), alpha-1-acid-glycoprotein (AGP), corticosterone (CORT), ovotransferrin (OVT), and dopamine (DA) in duck embryos and hatchlings.Methods: Fertilized Khaki Campbell duck eggs were subjected to the following auditory stimulation treatments: 1) no supplementary sound treatment other than the background sound of the incubator's compressors at 40 dB (CONTROL), 2) exposure to pre-recorded traffic noise at 90 dB (NOISE), and 3) exposure to Mozart's Sonata for Two Pianos in D Major, K 488 at 90 dB (MUSIC). The NOISE and MUSIC treatments were lasted for 20 min per hours over a 24 h (a total of 8 h/d), starting from embryonic days (ED) 13 to hatching. PAS did not influence hatchability rate, body weights at ED 21 and post-hatch day (PH) 1.Results: The MUSIC and NOISE treatments elevated HSP70 at ED21 compared to the Control, while opposite results were observed at post-hatch day 1 (PH1). The AGP, CPN and CORT were not significantly (p>0.05) affected by PAS at ED21. However, at PH1, the Control ducklings showed significantly higher OVT and AGP. The NOISE and MUSIC treatments reduced DA activity in ED21 and PH1, respectively.Conclusion: PAS induces a physiological stress response in embryos without affecting hatchability or the weights of hatchling. Exposure to MUSIC and NOISE modulates stress-related physiological markers during incubation and hatching, hence enhancing stress resilience in day-old ducklings.