Ammonia emissions in tunnel-ventilated broiler houses

Abstract

Gas production in broiler houses and their emissions are closely related to the microclimate established inside the house according to air temperature, humidity, and velocity. Therefore, the internal house environment is influenced by building typology and ventilation system. The objective of the present study was to evaluate ammonia emission rates in broiler houses equipped with different ventilation systems (negative or positive pressure) and litter conditions (new or built-up). The environment of six commercial broiler houses was evaluated internal and external NH3 concentrations. Ventilation rates were recorded to estimate ammonia emission rates. The efficiency of circulation and exhaust fans was assessed, and higher ventilation rates were determined in negative-pressure houses due to the higher flow of the fans. Houses with new litter increased ammonia emission rates along the rearing period, indicating the relationship between gas emissions, bird age and ventilation rates, and presented a typical curve of NH3 emission increase. Negative-pressure houses with built-up litter presented higher emission rates during the first rearing week due to the high NH3 concentration during the brooding period, when the ventilation rates required to maintain chick thermal comfort are low. Although the results of the present study indicate an advantage of the positive-pressure systems as to gas emissions, further research is needed reduce gas emissions in broiler houses with negative-pressure systems

Effect of a simulated heat wave in thermal and aerial environment broiler-rearing environment

“…LIMA et al (2011) found out simultaneous increasing in temperature and ammonia concentration as observed on this study (Figure 2). …”

Model-predicted ammonia emission from two broiler houses with different rearing systems

“…Ambient air temperature is considered a primary factor in regulating the chemical processes involved in ammonia emissions (Wheeler et al, 2006;Sommer et al, 2006;Casey et al, 2010). Previous studies showed that the distribution uniformity of environmental features may affect broiler weight gain (Miragliotta et al, 2006;Lima et al, 2011).…”

Emissões de gases de efeito estufa e amônia oriundas da criação de frangos de corte em múltiplos reúsos da cama

“…Poucos são os estudos disponíveis na literatura sobre as emissões de N2O e CH4 do manejo dos dejetos de frangos na sua própria criação, muito menos informações acerca do comportamento desses gases em galpões típicos de regiões tropicais. Para a avicultura brasileira, os estudos limitam-se a avaliar a concentração de amônia (MIRAGLIOTA et al, 2004;LIMA et al, 2011;OSORIO-SARAZ et al, 2014;MENDES et al, 2014;LIMA et al, 2015) em aviários, visando o desempenho e bem-estar animal (OWADA et al, 2007). Embora a amônia não seja diretamente causadora do efeitoestufa, devido à sua alta produção na atividade avícola, seu efeito indireto deve ser considerado nos inventários.…”

“…Recentes pesquisas têm sido realizadas no Brasil sobre a emissão de NH3 em galpões de frangos (MIRAGLIOTTA et al, 2004;LIMA et al, 2011;MENDES et al, 2014;LIMA et al, 2015). No entanto, estudos sobre as emissões de GEE ainda são escassos.…”

“…No entanto, estudos sobre as emissões de GEE ainda são escassos. Lima et al (2011) apresentaram emissão de NH3 para frangos de corte em diferentes condições de criação (cama nova vs. cama usada) combinadas com diversas densidades de alojamento. Osorio-Saraz (2014) adaptou um método de câmara estática para determinar as taxas de NH3 em galpões de frangos em condições brasileiras, e Souza e Mello (2011) apresentaram um inventário das emissões de NH3 para todas as categorias de animais domésticos do Estado do Rio de Janeiro.…”