Physiological response, meat quality and gene expression in the skeletal muscle of broiler chickens under heat stress and supplemented with an antioxidant

• Grant number: 09/15624-4
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2010
• End date: February 29, 2012
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Ana Silvia Alves Meira Tavares Moura
• Grantee: Ana Silvia Alves Meira Tavares Moura
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The objective is to submit broiler chickens to heat stress from 28 to 42 days of age, in order to induce measurable changes in physiological responses and performance, and to investigate their effects on meat sensory properties and gene expression in the breast skeletal muscle. Additionally, we intend to investigate if diet supplementation with an antioxidant is capable of reducing, or neutralizing, these effects. Three hundred and eighty four male chickens from the Cobb strain will be assigned to a completely randomized design, with a 3 x 2 x 2 factorial arrangement (ambient temperatures, vitamins C and E supplemented above the recommended level, and stress periods) and 16 replicates. Chicks will be caged in groups of four in an environmental chamber, where they will be maintained in the thermoneutral zone up to 28 days. From this age on, they will be assigned to three groups: heat stress (33oC), thermoneutral zone (24oC) and thermoneutral zone with pair feeding (24oC with feed amount limited to the average consumed by the heat stressed chickens). Balanced diets according to phase will be provided. Rectal and body surface temperatures will be measured in two consecutive days of the week and body weight and feed consumption will be recorded weekly, from 28 up to 42 days of age. Meat sensory properties (pH, color, water holding capacity, cooking loss and shear force) will be evaluated in pectoralis major muscle samples. Expression of HSP70, avUCP, citrate synthase, glycogen phosphorylase and myostatin genes will be evaluated by quantitative real time RT-PCR, 18 hours and 12 days after the heat stress period was initiated, in the same muscle. We expect to contribute for the elucidation of the molecular mechanisms that occur in the skeletal muscle of broiler chickens as a result from acute and chronic heat stress in the growing and slaughter phases. The use of a pair feeding technique will allow to discriminate between the real direct effect of heat stress on the traits under study from its indirect effect on the reduction of feed intake. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ZEFERINO, C. P.; KOMIYAMA, C. M.; PELICIA, V. C.; FASCINA, V. B.; AOYAGI, M. M.; COUTINHO, L. L.; SARTORI, J. R.; MOURA, A. S. A. M. T.. Carcass and meat quality traits of chickens fed diets concurrently supplemented with vitamins C and E under constant heat stress. ANIMAL, v. 10, n. 1, p. 163-171, JAN 2016. (09/15624-4)