Thermal comfort index, physiological variables and performance of quails fed with protein reduction

Ladyanne R Rodrigues,Dermeval A Furtado,Fernando G P Costa,Evaldo De A Cardoso,José W B Do Nascimento

doi:10.1590/1807-1929/agriambi.v20n4p378-384

Abstract

ABSTRACT The objective of this study was to determine the effects of environment and electrolyte balance on environmental, physiological and productive indices of Japanese quails. For the experiment, 288 quails were distributed in a randomized block design with six treatments and six replicates of eight birds per experimental unit. The treatments consisted of one basal feed with 20.0% of crude protein (CP) and the others with a reduction of 3.0% CP to achieve six electrolyte balance levels (166.54; 153.47; 139.63; 139.63; 117.13 and 166.49). As to the environment, there was an increase in air temperature and temperature-humidity index at the hottest hours of the day, causing discomfort to the birds, which increased respiratory rate, but with the maintenance of homeothermy. Differences were observed in feed consumption, water consumption, production, weight of eggs and mass of eggs, due to the electrolyte levels in the feed. For feed conversion, both per mass and per dozen of eggs, there was no statistical difference. The electrolyte balance and environmental indices at the hottest hours of the day did not affect quail production.

Highlights

Quail farming is a poultry activity in expansion, responsible for the generation of jobs and income at all levels of the production chain, and its main products are eggs and meat, which are source of animal protein with high biological value (Moura et al, 2010)
Quails can be raised under heat conditions (Umigi et al, 2012), and the ideal air temperature, i.e., the thermal comfort zone (TCZ), for quails in the laying stage, is between 18 and 22 oC, with relative air humidity between 65 and 70% (Oliveira, 2007)
The treatments consisted of six diets: (T1) control feed, according to animal requirements (NRC, 2004) and based on corn and soybean bran, supplemented with DL-methionine and choline; from T2 to T6, the basal feed was supplemented with different levels of amino acids, in order to obtain six levels of electrolyte balance (166.54, 153.47, 139.63, 139.63 117.13 and 166.49)

Summary

Introduction

Quail farming is a poultry activity in expansion, responsible for the generation of jobs and income at all levels of the production chain, and its main products are eggs and meat, which are source of animal protein with high biological value (Moura et al, 2010). In order to maximize yield, production and product quality, quails must be well fed and raised in appropriate, equipped installations, such as in automated air-conditioned facilities, allowing the strains of breeders to externalize their production to the maximum. Thermal discomfort in laying poultry can cause a series of consequences, which in turn are closely related to the decrease in animal performance. Quails can be raised under heat conditions (Umigi et al, 2012), and the ideal air temperature, i.e., the thermal comfort zone (TCZ), for quails in the laying stage, is between 18 and 22 oC, with relative air humidity between 65 and 70% (Oliveira, 2007)

Objectives

Methods

Results