Effect of thermal stress on zootechnical performance and physiological and immunological parameters of laying hens

• Grant number: 20/14885-8
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2022
• End date: February 29, 2024
• Field of knowledge: Agronomical Sciences - Agricultural Engineering - Rural Buildings and Ambience
• Principal Investigator: Danilo Florentino Pereira
• Grantee: Danilo Florentino Pereira
• Host Institution: Faculdade de Ciências e Engenharia. Universidade Estadual Paulista (UNESP). Campus de Tupã. Tupã , SP, Brazil
• Associated researchers: Felipe André dos Santos ; Ricardo Velludo Gomes de Soutello ; Silvana Gomes Gonzalez

Abstract

Birds are known to get stressed quickly and, as a result, decrease their productivity. Better understanding of physiological, immunological and biological changes can help to avoid losses in zootechnical performance. The aim of this research is to verify the effect of heat stress on egg quality and physiological/biological changes in search of temperature conditions that will promote changes in global DNA methylation content and proteomic profile in laying birds, in response from better adaptive capacity of birds to intermittent thermal stress. Experiments will be carried out during the production phase of the birds under the influence of environmental conditions of comfort and thermal stress. Environments with constant temperatures of 23°C and 35°C will be tested, and environments with intermittent temperatures of 35°C (23°C) and 26°C (20°C), to simulate conditions of heat stress and thermoneutrality. The experimental design is in randomized blocks, with a split-plot scheme. To verify the physiological and biological indices (corticosterone concentration, plasma glucose, heterophil/lymphocyte ratio, hematological pattern, global DNA methylation and proteomic profile) samples will be taken from the blood of birds. For analysis of egg quality, the parameters egg weight, shell strength, albumen height, eggshell thickness, Haugh unit and specific gravity will be evaluated. It is expected to know better how heat stress affects the biology and physiology of chickens, especially about their adaptive capacity. (AU)