Ilda de Fátima Ferreira Tinôco

Evaluation of minimal ventilation and animal performance of broiler chickens in poultry houses during winter

The objective of this work was to evaluate a system of minimal or hygienic ventilation and its influence on thermal comfort, air quality and broiler zootechnical performance of poultries raised during the winter. Two similar sheds were used, with 9,500 Cobb broiler chickens per shed, during a complete productive cycle. In one of the sheds, a positive ventilation system that met minimal need of air renovation, composed by three fans with flow of 300 m3/min, was installed on the ceiling parallel to the floor. The other shed was considered control and did not have a ventilation system. For the first two weeks of age of the broilers, temperature and air relative humidity differed, and the system with minimal ventilation showed the worst comfort conditions. Broilers kept in no ventilation system showed the best results for slaughter weight (with ventilation - 1.549; with no ventilation - 1.577 kg), food conversion (with ventilation - 1.63 kg/kg and with no ventilation - 1.59 kg/kg) and productive efficiency (with ventilation - 285 and without ventilation - 297). There were some differences for concentration of contaminant gases, which were lower in the system with minimal ventilation. The system with minimum ventilation, the way it was designed in the experiment, significantly decreases the temperature inside the poultry shed, compromising the thermal comfort and damaging animal performance. Although the system with minimum ventilation results in lower gas concentrations, none of systems promotes average concentration of carbon dioxide and carbon monoxide harmful to birds.The objective of this work was to evaluate a system of minimal or hygienic ventilation and its influence on thermal comfort, air quality and broiler zootechnical performance of poultries raised during the winter. Two similar sheds were used, with 9,500 Cobb broiler chickens per shed, during a complete productive cycle. In one of the sheds, a positive ventilation system that met minimal need of air renovation, composed by three fans with flow of 300 m3/min, was installed on the ceiling parallel to the floor. The other shed was considered control and did not have a ventilation system. For the first two weeks of age of the broilers, temperature and air relative humidity differed, and the system with minimal ventilation showed the worst comfort conditions. Broilers kept in no ventilation system showed the best results for slaughter weight (with ventilation 1.549; with no ventilation 1.577 kg), food conversion (with ventilation 1.63 kg/kg and with no ventilation 1.59 kg/kg) and productive efficiency (with ventilation 285 and without ventilation 297). There were some differences for concentration of contaminant gases, which were lower in the system with minimal ventilation. The system with minimum ventilation, the way it was designed in the experiment, significantly decreases the temperature inside the poultry shed, compromising the thermal comfort and damaging animal performance. Although the system with minimum ventilation results in lower gas concentrations, none of systems promotes average concentration of carbon dioxide and carbon monoxide harmful to birds.

Análise do conforto térmico em galpões avícolas com diferentes sistemas de acondicionamento

A base deste trabalho foi a analise da influencia da tipologia e das condicoes de conforto termico ambiental em sete sistemas de acondicionamento de aviarios de frangos de corte, localizados na mesorregiao do Agreste paraibano. Os sistemas foram os seguintes: telha de amianto sem ventilacao artificial; telha de barro sem ventilacao artificial; telha de amianto com ventilacao artificial; telha de barro com ventilacao artificial; telha de amianto com ventilacao artificial e nebulizacao; telha de barro com ventilacao artificial e nebulizacao e telha de amianto com ventilacao artificial e aspersao sobre a cobertura. A avaliacao foi feita com base na temperatura do ar (TA), na umidade relativa (UR), no indice de temperatura de globo negro e umidade (ITGU) e na carga termica de radiacao (CTR) em diferentes horarios, durante o periodo de verao. Constatou-se influencia da tipologia nas condicoes de conforto termico e que em todos os sistemas os indices de conforto variaram ao longo do dia, sendo que a TA, o ITGU e a CTR, apresentaram valores considerados acima do ideal, enquanto a UR ficou dentro da zona de conforto termico.

Índice térmico ambiental de produtividade para frangos de corte

In this study, the influence of temperature, relative humidity and air velocity in the development process of Avian Farm male chickens was analyzed in order to develop an environmental thermal index for productivity of broiler chickens - IAPfc. The chickens were first raised from 1 to 21 days of age in a conventional poultry-shed under natural conditions. Between 22nd and 42nd day (slaughter) the chickens were kept in climatic chambers. The treatments consisted of combination of levels of variables: temperature (t) 16, 20, 26, 32 and 36 oC; relative humidity (u) 20, 34, 55, 76 and 90%, and air velocity (v) 0; 0.6; 1.5; 2.4 and 3.0 m s-1, according to the central rotatable composite design of the response surface methodology. The experimental diets attained the suggested requirements of each development phase. The diet composition was the same in all treatments. The analyzed parameters were: daily weight gain, feed intake, rectal temperature and respiratory rate. The statistical model obtained was IAPfc = 45.6026 - 2.31072 t - 0.368331 u + 9.70922 v + 0.0549243 t2 + 0.0012183 u2 + 0.66329 v2 + 0.0128968 tu - 0.300928 tv - 0.0595245 uv, which is based on the animal performance and physiological parameters.

Thermal environment and gas concentrations in poultry houses during heating.

Currently, the national and international markets are stressing actions for environmental preservation, including data collection regarding concentrations or emission of harmful gases generated from animal production. The lack of information regarding this subject is the reason for this study which is to diagnose the concentrations of carbon monoxide and carbon dioxide associated with the thermal comfort of broiler chickens in poultry houses. Two different types of air renovation for heating were studied: ventilation by negative pressure and by positive pressure, during winter in the southern region of Brazil. For evaluation of the thermal environment, randomized blocks were used in split-plot design with two repetitions. The index of the black globes temperature and humidity indicated the best conditions for thermal comfort environment in the first week of the life of the birds for positive pressure of the system. The highest gas concentrations were detected in the morning for both air renovation methods, with concentrations within the acceptable levels for good bird development.

Potencial da cinza do bagaço da cana-de-açúcar como material de substituição parcial de cimento Portland

This study is focused on the evaluation of the effects of the partial replacement of Portland cement by sugarcane bagasse ash (CBC) in mortars. The main objective was to find a suitable destination for an agricultural residue generated in an increasing amount in Brazil, as a result of the boom of the use of ethanol as an alternative fuel to gasoline. Also, the use of CBC as a mineral admixture in mortars and concretes contributes to a decrease in the environmental impact of these materials related to cement production. Experimental techniques were applied both for the CBC characterization and for the evaluation of its use as a mineral admixture in mortars, based on mechanical and physical tests. The yield of CBC from sugarcane bagasse burning was 10% (weight basis). The CBC presented a SiO2 content of 84% and a carbon content of 5%. Silica presented both amorphous and crystalline (cristobalite and quartz) structure. The pozzolanicity index applied indicates the reactivity of the CBC. Concerning the compression strength, the results from tests with mortars with up to 30% of CBC content indicated the viability of the partial substitution of cement by up to 20% of the CBC considered.

ATUALIZAÇÃO DAS TEMPERATURAS DE CONFORTO TÉRMICO PARA FRANGOS DE CORTE DE ATÉ 21 DIAS DE IDADE

Em decorrencia de alteracoes na genetica e nutricao, bem como na aclimatizacao das aves de corte ao clima do Brasil, as temperaturas atualmente preconizadas como otimas para criacao podem estar defasadas. Objetivou-se com esta pesquisa atualizar os valores de temperatura ambiente que caracterizam o conforto termico para frangos de corte de um a 21 dias de idade, sob condicoes brasileiras de producao. Esta pesquisa foi conduzida com 600 aves da linhagem COBB, que foram distribuidas em cinco câmaras climaticas, mantidas sob diferentes temperaturas, durante as tres primeiras semanas de idade. Durante o periodo experimental, os valores de temperatura media para as semanas de um a tres foram reduzidos progressivamente, constituindo-se de cinco tratamentos: T27/24/21; T30/27/24; T33/30/27; T36/33/30 e T39/36/33. Verificou-se que as aves mantidas sob o tratamento T3027-24 apresentaram melhor desempenho zootecnico quando comparadas as demais condicoes ambientes. Com base nos modelos de regressao obtidos, os valores de temperatura ambiente que proporcionam o maior ganho de peso para o periodo inicial de criacao de frangos de corte foram 31,3; 25,5 e 21,8 oC, respectivamente, na primeira, segunda e terceiras semanas de vida dos animais.

Comportamento de variáveis climáticas em sistemas de ventilação mínima para produção de pintos de corte

During the creation process of poultry, the initial or heating phase, is characterized as the most delicate period due to physiological immaturity of the birds. Thus, environmental factors stand out to infer, directly, in the growth, on the performance and maintenance of life of these animals. Based on these considerations, the aim of this study was to study the effect of three different systems of minimum ventilation (positive pressure, negative and natural) on environmental variables (air temperature, relative humidity and wind velocity) of broiler sheds during the heating phase. According to results obtained, it was verified that the heating system used was inadequate to maintain the air temperature and relative humidity within the standards deemed appropriate, thus exposing the birds to periods of heat stress by cold. In contrast, there were negative influences regarding ventilation rates applied to the two ventilation systems positive and negative. Wind velocity also remained at levels considered non-stressful for young chickens.

Operação de filtros orgânicos utilizados no tratamento de águas residuárias de suinocultura

This work consisted of study of operation of organic filters utilizing sugarcane bagasse and sawdust as filtering material. An experiment was carried out at the Experimental Area of Hydraulics, Irrigation and Drainage of the Department of Agricultural Engineering, Federal University of Vicosa. Columns with 1.0, 1.3, 1.6, 1.9 and 2.0 m of height were filled with the organic material for the swine wastewater filtering, with three replicates. Piezometers were installed for the head loss monitoring. The filters were operated during 100 to 150 min until the filtering rate was less than 0.2 L m-2 s-1. Removal rates between 90 to 99% for suspended solids (SS) and 43 to 53% for total solids (TS) were reached, using sawdust filters, and 81 to 96% for SS and 55 to 56% for TS, using canetrash filters. The filtration efficiency increased with time, due to gradual obstruction of the pores in the filter columns. The height of filter column did not alter significantly filter efficiency in removing SS.

NDIR Gas Sensor for Spatial Monitoring of Carbon Dioxide Concentrations in Naturally Ventilated Livestock Buildings.

The tracer gas ratio method, using CO2 as natural tracer, has been suggested as a pragmatic option to measure emissions from naturally ventilated (NV) barns without the need to directly estimate the ventilation rate. The aim of this research was to assess the performance of a low-cost Non-Dispersive Infra-Red (NDIR) sensor for intensive spatial field monitoring of CO2 concentrations in a NV dairy cow house. This was achieved by comparing NDIR sensors with two commonly applied methods, a Photo-Acoustic Spectroscope (PAS) Gas Monitor and an Open-Path laser (OP-laser). First, calibrations for the NDIR sensors were obtained in the laboratory. Then, the NDIR sensors were placed in a dairy cow barn for comparison with the PAS and OP-laser methods. The main conclusions were: (a) in order to represent the overall barn CO2 concentration of the dairy cow barn, the number of NDIR sensors to be accounted for average concentration calculation was dependent on barn length and on barn area occupation; and (b) the NDIR CO2 sensors are suitable for multi-point monitoring of CO2 concentrations in NV livestock barns, being a feasible alternative for the PAS and the OP-laser methods to monitor single-point or averaged spatial CO2 concentrations in livestock barns.

Análise de imagens digitais para a avaliação do comportamento de pintainhos de corte

The aim of this study was to evaluate the behavior of young chickens in the first two weeks of life through digital images processing, for the determination of the best condition of animal welfare. The experiment was accomplished at two buildings with furnace with indirect air heating, used for creation of 15,200 broiler chickens by building, during one single productive cycle. For the production of digital images, two video cameras were installed by building. One of the cameras had an inclination of 45o and the other a 90o in relation to the ground. The images were analyzed for each daily climatic condition. Then, they were binarized and processed through grouping/dispersion descriptor and correlated with the values of temperature of the air. Correlation was observed between the descriptor and the values of temperature of the air. Images obtained by the camera positioned at 45o had the highest correlation. From the data obtained can be observed that the grouping/dispersion and the behavior of the young chickens can be used as indicator of the states of thermal comfort and that the descriptor was efficient for the quantification.