Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sensors (Basel) ; 22(12)2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35746354

RESUMO

A dust generator was developed to disperse and maintain a desired concentration of airborne dust in a controlled environment chamber to study poultry physiological response to sustained elevated levels of particulate matter. The goal was to maintain an indicated PM10 concentration of 50 µg/m3 of airborne dust in a 3.7 m × 4.3 m × 2.4 m (12 ft × 14 ft × 8 ft) controlled environment chamber. The chamber had a 1.5 m3/s (3200 cfm) filtered recirculation air handling system that regulated indoor temperature levels and a 0.06 m3/s (130 cfm) exhaust fan that exchanged indoor air for fresh outdoor air. Dry powdered red oak wood dust that passed through an 80-mesh screen cloth was used for the experiment. The dust generator metered dust from a rectangular feed hopper with a flat bottom belt to a 0.02 m3/s (46 cfm) centrifugal blower. A vibratory motor attached to the hopper ran only when the belt was operated to prevent bridging of powdered materials and to provide an even material feed rate. A laser particle counter was used to measure the concentration of airborne dust and provided feedback to an Arduino-based control system that operated the dust generator. The dust generator was operated using a duty cycle of one second on for every five seconds off to allow time for dispersed dust to mix with chamber air and reach the laser particle counter. The control system maintained an airborne PM10 dust concentration of 54.92 ± 6.42 µg/m3 in the controlled environment chamber during six weeks of continuous operation using red oak wood dust. An advantage of the automatically controlled dust generator was that it continued to operate to reach the setpoint concentration in response to changes in material flow due to humidity, partial blockages, and non-uniform composition of the material being dispersed. Challenges included dust being trapped by the recirculation filter and the exhaust fan removing airborne dust from the environmental chamber.


Assuntos
Poluição do Ar em Ambientes Fechados , Poeira , Poluição do Ar em Ambientes Fechados/análise , Poeira/análise , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado , Pós
2.
Poult Sci ; 101(5): 101796, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35364456

RESUMO

Avian necrotic enteritis (NE) is an infectious disease that impacts poultry worldwide causing economic losses. Discontinued use of antimicrobial growth promoters has been associated with high incidence of the disease, which has led to a necessity for finding new therapeutic alternatives. Flavonoids are polyphenolic compounds that have been studied for their health-promoting properties in animals and humans. This study presents a flavonoid-rich corn (PennHFD), as a potential alternative for ameliorating NE in broiler chickens. The effect of a diet formulated with PennHFD was compared to a diet based on commercially available corn in chickens subjected to a controlled challenge of NE based on a co-infection of Eimeria maxima and Clostridium perfringens. Birds fed on the PennHFD-based diet had lower incidence of intestinal lesions (P = 0.048), higher body weight gain (P < 0.01), lower feed conversion ratio (P < 0.01), and lower mortality rates (P = 0.023) compared to the control diet. Therefore, we concluded that the inclusion of the high-flavonoid PennHFD reduces the severity of an experimental challenge of NE in broiler chickens.


Assuntos
Enterite , Doenças das Aves Domésticas , Animais , Galinhas , Dieta/veterinária , Enterite/patologia , Enterite/prevenção & controle , Enterite/veterinária , Flavonoides , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/prevenção & controle , Zea mays
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...