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Sound stimuli in artificial egg incubation: their effects on the hatching, productive performance and post-hatch behavior of broiler chicks

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Author(s):
Ana Carolina Donofre
Total Authors: 1
Document type: Doctoral Thesis
Press: Piracicaba.
Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
Defense date:
Examining board members:
Iran José Oliveira da Silva; José Fernando Machado Menten
Advisor: Iran José Oliveira da Silva
Abstract

The physical factors that involve artificial incubation are determinant to the embryonic development, hatching and performance of chicks. Although many of them are highly regarded, there are other issues capable of improving or adapting the process to new animal-production demands. The current research addresses the bioacoustics as one of such issues, which motivated the investigation of the sound stimuli in artificial incubation, relating the noise of the commercial hatcheries and the addition of vocalizations of the species with physiological, productive and behavioral of chicks. Initially, the Chapter 3 presents the measuring the sound pressure level (SPL) inside eggs. To do so, a small sensor (miniaturized decibel meter) was developed in the Arduino® platform. The sensor was calibrated and tested under specific conditions to collect information, such as sound wave isolation by egg shells and SPL values close to the embryos. Experimental incubations with treatments based on the association between two noise SPLs of the hatcheries [70 or 90 dB (A)] with, or without, the addition of species-specific vocalizations (natural stimulus). These treatments were evaluated on embryo growth and hatch responses (Chapter 4) and chicks performance in the first week of life (Chapter 5). Against all expectations, egg exposure to the highest SPL, which simulated the noise of commercial hatcheries, reduced the time necessary for hatching, besides increasing the hatchability, as well as the quality of the navel and hocks, of chicks. On the other hand, species-specific vocalizations were only influential when they were associated with 70 dB SPL (A). The exposure to lower NPS resulted in higher feed intake and lower feed conversion with better results in exposure to 90 dB (A) or in the presence of vocalizations. Finally, in Chapter 6, behavioral tests such as tonic immobility, social isolation and open field tests applied to chicks hatching from the incubation treatments described above. The tests comprised three post-hatching periods (24, 72 and 120 hours) and two conditions (silence or species-specific vocalizations in the background). The effects of incubation treatments were just observed in some responses and 24 hours after hatching. The exposure to the vocalizations during embryonic development reduced chicks\' movement and vocalization level, which was associated with lower stress. It is concluded that sound stimulation in hatcheries can alter productive responses and behavior of chicks after hatching. (AU)

FAPESP's process: 15/04352-4 - Sounds stimulation on incubated of fertilized eggs and its relations with birth, physiological, behavioral, and productive performance in broilers chicks
Grantee:Ana Carolina Donofre
Support Opportunities: Scholarships in Brazil - Doctorate