Effect of specific sound frequency on production performance, egg quality and physiological characteristics of laying hens

The study investigated the effects of violin note B7 (Violin), double bass note E1 (Bass) and Mozart's Sonata for Two Pianos in D Major, K. 448 (Mozart), on laying hens in terms of the production performance, egg quality and physiological characteristics. One hundred and sixty 600-day-old laying hens (ISA Brown) were randomly categorised into four groups with four replicates (10 hens/ replicate), and exposed to specific sound frequency for 12 weeks. The results indicated that Violin group presented significantly higher thick albumin height, Haugh unit and yolk index compared to the control group (p < .05). The treatment groups exhibited higher level of glutathione peroxidase in the jejunum-ileum and serum compared to the control group (p < .05). The Violin and Bass groups displayed lower levels of interleukin (IL)-1 beta in the jejunum-ileum, while the levels of IL-6 were lower in treatment groups compared to the control group (p < .05). The expression of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B) gene was lower in the treatment groups than the control group (p < .05). Bass and Mozart groups exhibited lower messenger RNA (mRNA) level of inducible nitric oxide synthase (iNOS) and tumour necrosis factor-alpha (TNF-alpha) compared to those in the control group. The number of ASVs (amplicon sequence variants) in the jejunum-ileum of the Violin group was three times higher than that in the control group. These observations suggest that specific sound frequency stimulation can enhance the egg quality and also aid in regulating oxidative stress of laying hens.