Effects of heat stress on production and egg quality of hens of two commercial breeds

• Grant number: 22/12812-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: December 31, 2023
• Field of knowledge: Agronomical Sciences - Agricultural Engineering - Rural Buildings and Ambience
• Principal Investigator: Danilo Florentino Pereira
• Grantee: Eric Hideki Ivasaki
• Host Institution: Faculdade de Ciências e Engenharia. Universidade Estadual Paulista (UNESP). Campus de Tupã. Tupã , SP, Brazil

Abstract

High temperatures negatively affect the productive performance of chickens. The objective of this research is to evaluate the effect of heat stress on production and egg quality of laying hens of two commercial breeds (white and red) housed in a climatic chamber under four conditions of thermal environment. Experiments will be carried out during the production phase of the hens under the influence of environmental conditions of comfort and thermal stress. Environments with constant temperatures of 23°C and 35°C, and environments with intermittent temperatures of 35ºC (23ºC) and 26ºC (20ºC) will be tested to simulate conditions of heat stress and thermoneutrality. Each environmental condition will be applied to a group of 50 chickens (25 from each strain) for 35 days, the first seven days being considered as an adaptation period. The experimental design is in randomized blocks, with a split-plot scheme. Egg quality will be determined from the analysis of the variables egg weight, shell strength, albumen height, eggshell thickness, Haugh unit and specific gravity, for all eggs collected in the last three days of each temperature treatment. . The amount of eggs produced will be recorded daily for each strain in each treatment. It is expected to know better how heat stress affects the zootechnical performance of chickens.