Banca de DEFESA: MARCELO BAHUTI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MARCELO BAHUTI
DATA: 27/01/2025
HORA: 14:00
LOCAL: Webconferência
TÍTULO:

EVALUATION AND MODELING OF RESPONSES OF LAYING HENS SUBJECTED TO DIFFERENT ILLUMINANCE LEVELS

PALAVRAS-CHAVES:

poultry farming; light intensity; hen performance; artificial intelligence; fuzzy inference system; smart production; zootechnical responses prediction

PÁGINAS: 113
GRANDE ÁREA: Ciências Agrárias
ÁREA: Engenharia Agrícola
SUBÁREA: Construções Rurais e Ambiência
ESPECIALIDADE: Engenharia de Construções Rurais
RESUMO:

This study aimed to investigate the impact of different illuminance levels and exposure times to these illuminances on laying hens during the peak production phase. The experiment was conducted in climate-controlled wind tunnels, which allowed for precise control of environmental variables such as temperature, relative humidity, air velocity, and light intensity. The treatments provided 5, 20, 50, and 100 lux illuminance levels using cold white light-emitting diode (LED) lamps. The thermal variables were adjusted to remain within the comfort ranges recommended for laying hens aged 25 to 36 weeks. Additionally, the feed provided to the hens was balanced according to the nutritional requirements for this strain at this developmental stage. 72 Hy-Line W-80 laying hens were used, divided into three experimental flocks of 24 birds per flock. Each flock was housed for 28 days, including an initial acclimation period of 7 days. During the experimental phase, data were collected on physiological responses (cloacal temperature, surface temperature, and respiration rate), productive responses (feed intake, water intake, feed conversion, body weight, egg weight, laying percentage, and percentage of viable eggs), and egg quality indicators (egg specific gravity, eggshell density, eggshell thickness, percentages of yolk, albumen, and shell, Haugh unit, and yolk index). The analyses and results were presented in Article 1 (statistical analysis of response variables) and Article 2 (comparison of modeling approaches as predictive tools to support decision-making). Initially, the efficiency of the thermal and luminescent control system inside the wind tunnels was verified. The observed temperature, relative humidity, and illuminance values showed lower standard deviations than the desired values. Furthermore, the averages of these variables did not differ significantly among the three experimental flocks, confirming the efficiency of environmental control and the quality of the experiment. Regarding the responses evaluated in Article 1, the results indicated that the tested illuminance levels did not significantly impact the evaluated parameters when analyzed in isolation. However, illumination exposure times influenced variables such as cloacal and surface temperatures, feed intake, body weight, and albumen percentage. Based on these results, 28 days was recommended as the minimum acclimation period for Hy-Line W-80 laying hens during the production phase. Moreover, as no significant differences were observed among treatments, it was found that environments with 5 lux are sufficient to ensure adequate access to food and water for the birds without compromising welfare or production. These findings suggest that environments with lower illuminance can reduce production costs, as their lighting systems require lower energy power compared to systems operating at 100 lux. In Article 2, statistical and fuzzy modeling approaches were applied to accurately predict laying hens' feed intake and surface temperature subjected to different lighting challenges. The developed models demonstrated high accuracy, with a notable advantage for fuzzy inference system (FIS)-based models. The results highlight the applicability of artificial intelligence techniques for simulating complex scenarios, optimizing management, and reducing production costs. Based on expert knowledge, the FIS modeling proved to be an efficient tool for decision-making in modern poultry farming, contributing to a balance between animal welfare, productivity, and sustainability. In summary, it is concluded that LED lighting offers significant energy efficiency and environmental management benefits, as it enables energy savings and reduces electronic waste compared to traditional light sources. Moreover, these benefits were achieved without compromising the welfare or productive performance of the birds. Therefore, this study contributes to the literature by clarifying the relationship between artificial lighting and laying hens management, proposing light intensity adjustments as a viable strategy to meet the productive and environmental demands of modern poultry farming.

MEMBROS DA BANCA:
Externo à Instituição - DIAN LOURENÇONI - UNIVASF (Suplente)
Externo à Instituição - GREGORY MURAD REIS - UF (Membro)
Externo à Instituição - IRAN JOSE OLIVEIRA DA SILVA - USP (Membro)
Externo ao Programa - LEONARDO SCHIASSI - DEA/EENG (Suplente)
Presidente - TADAYUKI YANAGI JUNIOR (Membro)
Externo à Instituição - YAMID FABIÁN HERNÁNDEZ JULIO - UNISINÚ (Membro)
Externo à Instituição - VASCO MANUEL FITAS DA CRUZ - UEv (Membro)