Effect of length of period hatching on the quality of chicks and its performance under heat stress

• Grant number: 14/23665-0
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): January 20, 2015
• Effective date (End): May 19, 2015
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal researcher: Isabel Cristina Boleli
• Grantee: João Batista Matos Junior
• Supervisor abroad: Giuseppe Maiorano
• Home Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Research place: Universita degli Studi del Molise, Italy
• Associated to the scholarship: 12/14428-0 - EFFECT OF DURATION OF HATCHING PERIOD ON QUALITY CHICKS ON THE QUALITY AND PERFORMANCE AHEAD OR NOT HEAT STRESS, BP.DR

Abstract

This study aims to present the Scholarship PhD project Process:. (2012 / 14428-0) approved by FAPESP which was conducted in order to investigate the effect of length of hatching on chicks quality and their performance under heat stress conditions. For this, three experiments were performed. In Experiment 1, fertile eggs from broiler (Cobb 500®) were incubated at 37.5°C and 60% RH until the 12th day. From the 13th day of incubation to hatching, two incubators were maintained at 37.5°C and two incubators had temperature raised to 39.0°C. The prenatal and post-incubation were evaluated the characteristics of eggshells, and at the hatching of birds the quality of the chicks, the duration of incubation and also lung and blood characteristics of chicks were evaluated. In Experiment 2, after hatching, the thermoneutral zone of birds according to incubation temperature (37.5°C and 39°C) was determined using means of a thermal preference test and a thermal challenge, which were performed on the 1st, 7th, 14th, 21st, 28th and 35th days of life and in subsequent days respectively. In Experiment 3, soon after hatching, the chicks of eachincubation treatment (37.5°C and 39°C) were housed in climate-controlled environment chambers maintained at three different temperatures: thermoneutral recommended for the commercial strain, thermal preference (determined from data from experiment 2) and hot relative to the thermal preference. At 42 days of age were analyzed performance characteristics, carcass yield, blood, meat quality and hypertrophy and hyperplasia of muscle fibers. The data obtained in Experiments 1 and 2 were observed, as the presence of outliers, normality of errors (testing Cramer-von-Mises) and homogeneity of variances (Levene's test). After verified the compliance with the assumptions of the model, the data were subjected to analysis of variance using the SAS program and, in case of significant differences, Tukey test (5%) was used to compare means. These data have been presented in two Partial reports submitted to FAPESP and their respective manuscripts are in preparation.The purpose of the internship, abroad with the laboratory of Prof. Dr. Giuseppe Mariano, at the University of Molise, Italy, is to improve our knowledge in the field of animal production and, more specifically, the evaluation of meat quality. It is intended to compare and discuss methodologies used to analyze and discuss the results obtained in Experiment 3 consistently, seeking to understand the interactions between: (a) heat stress in incubating, hypertrophy and fibrillar composition of muscle and meat quality; (b) heat stress in grow out phase, hypertrophy and fibrillar composition of muscle and meat quality; (c) period of hatching, hypertrophy and fibrillar muscle composition and meat quality.Keywords: hatching, heat stress, poultry, thermal preference, meat quality (AU)