The effect of manure and litter handling and indoor climatic conditions on ammonia emissions from a battery cage and an aviary housing system for laying hens

Ammonia emissions from both traditional and new welfare-based housing systems for laying hens must be reduced to prevent detrimental effects on the environment. In a comparative study, the effect of manure handling (variation in drying and removal frequency) in a battery cage and the effect of manure handling (as in battery cage system) and litter treatment (removal of litter) in a Tiered Wire Floor (TWF) aviary system on the emission of ammonia were investigated. Each system housed 6480 hens, treatments were varied in time, and effects were analysed by means of time-series analysis. The hens in the TWF system dropped 22.5% of their excreta in the litter and the remaining part, like all manure in the battery cage system, was dropped on the manure belts. The estimated emission from the manure on the belts in both systems was 18.8 g/h (daily mean, manure removal twice a day), whereas the emission from the litter in the TWF system amounted to 62.5 g/h. Emission from the belt manure on a typical day increased by 14, 39, 109 and 177% from the 1st until the 4th day after manure removal. The effect of increasing temperature and water vapour pressure difference on emission was +17% and -22% per degree and per kPa, respectively. Drying of manure on the belts increased the dry matter content of the manure and showed a tendency towards lower emissions. The dry matter content of the litter varied between 780 and 840 g/kg, the mean total nitrogen content was 3.3% of the dry matter, and the layer thickness varied between 2 and 9 cm. Both the ammonia content, which ranged between 20 and 190 mg/kg, and the layer thickness of the litter influenced the emission from the litter positively

Quality of poultry litter submitted to different treatments in five consecutive flocks Qualidade da cama de frango submetida a diferentes tratamentos em cinco lotes consecutivos

It was evaluated the effects of poultry litter treatment on moisture content, pH, density and volatilized ammonia for five consecutive flocks of broiler chicken breeding. It was used 640 birds per flock as a complete randomized design with eight treatments and four replicates. The treatments were the following: 1 non-treated litter; 2 litter submitted to in-house composting; 3 litter treated with aluminum sulfate; 4 litter submitted to gypsum; 5 litter treated with quicklime; 6 litter treated with dolomitic limestone; 7 litter treated with zeolite and 8 litter treated with charcoal. Chopped elephant-grass hay was used as poultry litter in all flocks. Fermentation in the shed increased moisture content of the litters in the second and first flocks on 21 and 42 days of breeding, respectively. There was no difference on density among treatments. Aluminum sulfate reduced pH of the litters in all flocks at 21 days of breding. On 42 days of breeding, pH of the litters was reduced in the litters with aluminum sulfate and gypsum in the first, second and forth flocks. On 21 days, aluminum sulfate reduced the volatilized ammonia in the first, third and forth flocks, and on 42 days, there was a reduction of volatilized ammonia in the litters with aluminum sulfate in the forth flock. Aluminum sulfate can improve quality of poultry litter of chopped elephant-grass hay by reducing pH and ammonia volatilization.<br>Foram avaliados os efeitos do tratamento da cama de frango sobre o teor de umidade, o pH, a densidade e a amônia volatilizada durante cinco lotes consecutivos de criação de frangos de corte. Foram utilizadas 640 aves por lote em delineamento inteiramente casualizado com oito tratamentos e quatro repetições. Os tratamentos foram: 1 cama não-tratada; 2 cama submetida à compostagem dentro do galpão; 3 cama tratada com sulfato de alumínio; 4 cama tratada com gesso agrícola; 5 cama tratada com cal virgem; 6 cama tratada com calcário dolomítico; 7 cama tratada com zeolita; e 8 cama tratada com carvão vegetal. O feno de capim-elefante picado foi utilizado como cama de frango em todos os lotes. A fermentação no galpão aumentou o teor de umidade das camas no segundo e primeiro lotes aos 21 e 42 dias de criação, respectivamente. Não houve diferença na densidade entre os tratamentos. O sulfato de alumínio reduziu o pH das camas em todos os lotes aos 21 dias de criação. Aos 42 dias, o pH das camas foi reduzido nas camas contendo sulfato de alumínio e gesso agrícola no primeiro, segundo e quarto lotes. Aos 21 dias, o sulfato de alumínio reduziu a amônia volatilizada no primeiro, terceiro e quarto lotes e, aos 42 dias, houve redução da amônia volatilizada das camas contendo sulfato de alumínio no quarto lote. O sulfato de alumínio pode melhorar a qualidade da cama de frango de feno de capim-elefante picado, por reduzir o pH e a volatilização de amônia