The objective of this study was to evaluate the thermal comfort of broilers reared under two lighting programs (almost continuous and intermittent) in broiler houses with yellow or blue lateral curtains. The experiment was carried out from June 24, 2004 until May 12, 2005. Six consecutive flocks were housed in four 12 × 10 m broilers houses internally divided into four pens of 200 birds each. Six flocks were raised on the same litter. The registration of data was accomplished at 3-hour intervals, for 24 hours twice a week. In the center of each pen and outside the house, dry and wet bulb temperatures, black globe temperature, and air velocity were collected. Based on the data collected at each time, air temperature (AT) (ºC), black globe humidity temperature index (BGHTI), radiant thermal load (RTL) (W/m²), and relative air humidity (RH) were determined. Harmonic analysis was used to estimate m, R, and f parameters. In general, the best results in terms of thermal comfort for the birds were found when near-continuous lighting program and yellow curtain were used.

The objective of the present study was to evaluate mortality and performance, darkling beetle population (Alphitobius diaperinus), light intensity, electrical energy consumption and economic efficiency of broilers reared under two lighting programs (nearly continuous or intermittent) and two curtain colors (yellow or blue). The experiment was conducted between June, 2004 and May, 2005. Six flocks were sequentially housed in four 12 × 10 m broiler houses divided into 4 pens with 200 birds each. Litter was reused six times or until flock 6. Body weight and feed conversion were determined on days 21, 35, and 42 of each flock. Mortality was recorded daily. Electrical energy consumption was recorded at the end of the grow-out of each flock (every 42 days). A completely randomized design in a 6 × 2 × 2 factorial arrangement (flocks, lighting programs, curtains) with four replicates per treatment was applied. Broilers reared in houses with yellow curtains and under nearly continuous lighting programs presented the best feed conversion ratio and the highest body weight. Nearly continuous lighting programs resulted in 1.48 times more sudden deaths and 1.34 times higher general mortality when compared with intermittent lighting programs. Electrical energy consumption was 2.12 times higher in nearly continuous lighting programs in relation to intermittent lighting programs. The presence of darkling beetles was higher in broiler houses with blue curtains and intermittent lighting program. The economic analysis showed the feasibility of using a mixed system, with intermittent light program in winter and spring and nearly continuous lighting program in the summer and autumn, both in broiler houses with yellow curtains.

The objective of the present study was to evaluate carcass and parts' yield, abdominal fat deposition and breast and foot pad blisters of broilers reared under two lighting programs (nearly continuous or intermittent) in broilers houses with yellow and blue curtains. The experiment was conducted between June, 2004 and May, 2005. Six flocks were sequentially housed in four 12 × 10 m broiler houses divided into 4 pens with 200 birds each. The litter was reused six times or until flock 6. A completely randomized design in a 6 × 2 × 2 factorial arrangement (flocks, lighting programs, curtains) with four replicates per treatment was applied. A total of 288 birds were evaluated for carcass yield. Curtain color did not affect carcass or parts' yield. The effect of lighting program and curtain color on carcass yield may depend on other factors related to flock. Intermittent lighting program promoted the highest drumstick and thigh yields. Lighting programs and curtain colors did not affect abdominal fat deposition or the presence of breast and foot pad blisters.

Este trabalho foi conduzido com o objetivo de avaliar as condições térmicas ambientais em aviários com dois sistemas de ventilação e dois materiais de cama. O experimento foi realizado em quatro aviários de 12 m × 10 m para frangos de corte, divididos internamente em 4 boxes/aviário, com 200 aves/boxe por quatro lotes consecutivos, cada um com duração de 42 dias e com intervalo de vazio sanitário de 15 dias entre lotes. Os tratamentos testados foram dois sistemas de ventilação (fixo e oscilante) e dois tipos de material de cama (palhada de soja e casca de arroz). Foram coletadas no centro de cada boxe e no ambiente externo a temperatura de bulbo seco e úmido, a temperatura de globo negro e a velocidade do ar. Esses dados foram coletados em intervalos de três horas, de 8 às 18 horas, na quarta, quinta e sexta semanas de vida das aves. Com base nos dados coletados em cada horário, foram determinados o índice de temperatura de globo e umidade (WBGT) e a carga térmica radiante (RHL). Também foram feitas leituras da temperatura da cama por meio de termômetro infravermelho. Na análise dos dados de ambiente térmico interno, foram avaliados os efeitos de lote, ventilação, semana, hora e as interações dos fatores sobre as variáveis avaliadas, utilizando-se a teoria de modelos mistos para medidas repetidas. A ventilação proporcionada por ventiladores fixos e oscilantes comportou-se igualmente e não teve efeito sobre as variáveis estudadas. No entanto, as duas formas de ventilação são suficientes para amenizar as condições térmicas internas do aviário em relação ao ambiente externo. A umidade relativa do ar é maior quando se utiliza a casca de arroz como material para cama.

The objective of this study was to evaluate environmental thermal conditions in broiler houses with two different ventilation systems and two different litter materials. The experiment was carried out in four 12 m × 10 m broiler houses, internally divided in 4 boxes/poultry house, with 200 birds/pen for four consecutive flocks, each one with a duration of 42 days with 15 days of downtime between flocks. Treatments tested were two ventilation systems (stationary or oscillating fans), and two types of litter materials (soybean straw or rice husks). It was collected in the center of each pen and in the external enviroment, dry and wet bulb temperatures, black globe temperature, and air velocity. These data were collected at 3-hour intervals from 8:00 a.m. to 6:00 p.m. at the fourth, fifth and sixth week age of the bird. Based on the data collected at each time, wet and globe temperature index (WBGT) and radiant heat load (RHL) were determined. Litter temperature reaings were also performed by using an infrared thermometer. Effects of flock, ventilation, week, hour and the interactions among factors on the studied variables were evaluated in the analysis of the internal thermal environment by using the theory of mixed models for repeated measures. Ventilation provided by stationary and oscilating fans had equal behavior and it did not affect the studied variable. However, both ventilation systems are sufficient to soften internal thermal conditions in the broiler house in relation to the external environment. Relative humidity of the air is higher when rice husks is used as litter material.

Este trabalho foi conduzido com o objetivo de avaliar o desempenho produtivo, a mortalidade, a incidência de lesões no coxim plantar em frangos de corte e a carga de enterobactérias nas camas em dois sistemas de ventilação e dois materiais de cama. O experimento foi realizado em quatro aviários de 12 m × 10 m para frangos de corte, divididos internamente em quatro boxes/aviário, com 200 aves/boxe, durante quatro lotes consecutivos, cada um com 42 dias de duração e intervalo de vazio sanitário de 15 dias entre lotes. Foram avaliados dois sistemas de ventilação (fixo e oscilante) e dois tipos de material de cama (palhada de soja e casca de arroz). As variáveis de desempenho estudadas foram peso corporal, ganho de peso, mortalidade e a conversão alimentar das aves aos 21, 35 e 42 dias de idade. A mortalidade foi anotada diariamente e, para as análises, foi utilizada a mortalidade total. A avaliação de lesão, por exame macroscópico de coxim plantar, foi realizada em todas as aves na pesagem final. Também foram realizados exames quantitativos de enterobactérias na cama. As análises estatísticas foram realizadas utilizando-se a teoria de modelos mistos para medidas repetidas e a regressão logística. A cama de casca de arroz proporcionou melhor desempenho produtivo das aves em todas as idades estudadas. Os resultados não permitiram recomendar um sistema de ventilação, uma vez que ambos tiveram desempenhos semelhantes. O uso de cama de palhada de soja ocasiona alta porcentagem de lesão no coxim plantar das aves. A ocorrência de enterobactérias é menor em camas reutilizadas.

The objective of the present work was to evaluate the performance, mortality and the incidence of lesion on the foot-pad of broilers and litter enterobacteriaceae load in two ventilation systems and two litter materials. The experiment was carried out in four 12 m × 10 m broiler houses, internally divided in 4 pens, with 200 birds/pen for four consecutive flocks, each one with 42 days of duration and interval of 15 days of downtime between flocks. It was evaluated two ventilation systems (stationary and oscillating fans), and two litter materials (soybean straw and rice husks). Performance variables studied were body weight, weight gain, feed conversion ratio and mortality of birds at 21, 35, and 42 days of age. Flock mortality was daily recorded, and total mortality was used for analysis. Evaluation of lesions by using foot-pad macroscopic examination was performed in all birds at final weighing. It was also performed quantitative examinations of litter enterobacteria. Statistical analyses were performed by using the mixed model theory for repeated measures and logistical regression. Rice husks litter promoted the best performance of birds at all studied ages. Results did not permit to recommend a ventilation system inasmuch as both had similar performances. Soy straw litter causes a high incidence of foot-pad lesions. Enterobacteria occurrence is lower in reused litter.

A determinação de produtos eficazes para a desinfecção e que não causem danos ao meio ambiente é um grande desafio para a avicultura orgânica. Neste trabalho foram avaliadas as atividades antibacterianas de quatro desinfetantes: ácido peracético, amônia quaternária, hipoclorito de sódio a 1% e a 0,1% de cloro ativo e do composto de ácidos orgânicos (cítrico, lático e ascórbico), frente às amostras padrão de Escherichia coli, Salmonella enteritidis e Staphylococcus aureus, na presença e ausência de matéria orgânica, sob duas diferentes temperaturas e tempo de contato de 20 minutos. Os ácidos orgânicos mostraram-se menos efetivos na presença de matéria orgânica. No entanto, o ácido peracético, na ausência desta, foi o mais eficaz frente à S. Enteritidis e igualmente efetivo, independente da matéria orgânica, frente ao S. aureus e E. coli, revelando-se uma opção válida para desinfecção na avicultura orgânica, desde que precedida de limpeza criteriosa.

Efficient products in the disinfection that do not cause damages to the environment are a challenge for the organic poultry keeping. The antibacterial activity of four disinfectants was evaluated to per acetic acid, quaternary ammonium, sodium hypochlorite at 1% and 0,1% and the composed of organics acids (citric, lactic and ascorbic) against standard samples of Escherichia coli, Salmonella enteritidis and Staphylococcus aureus in the presence and absence of organic matter, at two different temperatures and with 20 minutes of contact. Organic acids were shown less effective in the presence of organic matter. However, the per acetic acid in the absence of this revealed most efficient against S. Enteritidis and equally effective in the presence of organic matter, against S. aureus and E. coli showing a valid option for disinfection in the organic poultry keeping since preceded of careful cleanness.

Analisou-se histopatologicamente, o efeito da suplementação de dois por cento (2%) de oxigênio nas máquinas de incubação, durante o período embrionário, sobre corações e pulmões de aves no primeiro e no 40º dia de vida. A descrição das alterações histológicas dos órgãos revelou que as aves que receberam a suplementação apresentaram menores graus de lesões nos tecidos estudados e redução da taxa de mortalidade dos frangos.

Histopathological analysis of broiler chicken lungs and hearts were made to determine the effect of 2% oxygen supplementation during the hatchery period on the first and the 40th days of ages. The histopathological description response of the heart and lung indicated that oxygen supplementation during egg incubation, carried out in this work, resulted in less severe changes in chick’s organs and reduction of the mortality rates.