Heat stress impairs egg production in commercial laying hens infected by fowl typhoid

Author(s)

Rubio, Marcela da Silva ^[1] ; Rodrigues Alves, Lucas Bocchini ^[1] ; Viana, Guilherme de Brito ^[1] ; Benevides, Valdinete Pereira ^[1] ; Spina de Lima, Tulio ^[1] ; Santiago Ferreira, Taisa ^[1] ; Almeida, Adriana Maria de ^[1] ; Barrow, Paul Andrew ^[2] ; Berchieri Junior, Angelo ^[1]

Affiliation

^[1] Sao Paulo State Univ FCAV UNESP, Post Grad Program Vet Med & Agr & Livestock Micro, Sch Agr & Vet Sci, Jaboticabal - Brazil

^[2] Univ Nottingham, Sch Vet Med & Sci, Loughborough - England

• Document type: Journal article
• Source: AVIAN PATHOLOGY; v. 50, n. 2 JAN 2021.
• Web of Science Citations: 0

Abstract

Salmonella Gallinarum (SG) is an avian-restricted pathogen that causes fowl typhoid in poultry. Although it has been reported frequently over many decades in poultry flocks worldwide, the microorganism is more commonly associated with poultry in developing countries, particularly those with high ambient temperatures, where the acute form of the disease results in considerable economic losses. A more detailed investigation of environmental factors that affect the course of disease may assist in identifying effective prevention and control measures. Heat stress is known to impair the immunological response to a variety of pathogens and clearly may be an important contributory factor in the prevalence of disease in countries with warm or hot climates. Thus, the objective of the present study was to evaluate the effects of heat stress on chickens infected with SG. For this, light and semi-heavy commercial laying hens were distributed randomly within four groups as follows: infected and non-infected groups in rooms held at ambient temperature, and infected and non-infected groups under heat stress. Clinical signs, egg production, and mortality were recorded daily. Bacteriological counts in liver and spleen samples were estimated at 2, 5, 7, and 14 days post-infection. The results showed that both SG infection and heat stress had similar effects on egg production and a synergistic effect of the two stressors was observed. The data show an interaction between disease and heat stress which could point towards environmental and biosecurity approaches to resolving the possible 30% fall in production observed in such countries. (AU)

• FAPESP's process: 19/23634-1 - Evaluation of the effects of heat stress on laying hens infected with fowl typhoid
• Grantee: Guilherme de Brito Viana
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 18/03189-0 - Evaluation of avian infection (Gallus gallus domesticus) by Salmonella enteritidis, Salmonella typhimurium and Salmonella heidelberg containing deletion of the ttrA and pduA genes
• Grantee: Angelo Berchieri Junior
• Support Opportunities: Research Projects - Thematic Grants