Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth

The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs) are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length) were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo) in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree), Flemingia macrophylla (a shrubby legume) or Brachiaria decumbens (a pasture grass) was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms), Porcellionides pruinosus or Circoniscus ornatus (woodlice), and Trigoniulus corallinus (millipedes) were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.

Exposure to bioaerosols in poultry houses at different stages of fattening: use of real-time PCR for airborne bacterial quantification

Previous studies have demonstrated that poultry-house workers are exposed to very high levels of organic dust and consequently have an increased prevalence of adverse respiratory symptoms. However, the influence of the age of broilers, on bioaerosol concentrations has not been investigated. To evaluate the evolution of bioaerosol concentration during the fattening period, bioaerosol parameters (inhalable dust, endotoxin and bacteria) were measured in 12 poultry confinement buildings in Switzerland, at 3 different stages of the birds' growth; Samples of air taken from within the breathing zones of individual poultry-house employees as they caught the chickens ready to be transported for slaughter, were also analysed. Quantitative PCR (Q-PCR) was used to assess the quantity of total airborne bacteria and total airborne Staphylococcus species. Bioaerosol levels increased significantly during the fattening period of the chickens. During the task of catching mature birds, the mean inhalable dust concentration for a worker was 31 ± 4.7 mg/m3, and endotoxin concentration was 11'080 ± 3436 UE/m3 air, more than ten-fold higher than the Swiss occupational recommended value (1000 UE/m3). The mean exposure level of bird catchers to total bacteria and Staphylococcus species measured by Q-PCR is also very high, respectively reaching values of 72 (± 11) x107 cells/m3 air and 70 (± 16) x106/m3 air. It was concluded that in the absence of wearing protective breathing apparatus, chicken catchers in Switzerland risk exposure beyond recommended limits for all measured bioaerosol parameters. Moreover, the use of Q-PCR to estimate total and specific numbers of airborne bacteria is a promising tool for evaluating any modifications intended to improve the safety of current working practices.

Poultry Imported to Iowa, April 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, August 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, December 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, February 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, January 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, September 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, March 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, May 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, June 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, July 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, October 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, November 2015

The Poultry Imported to Iowa report monthly by the Department of Agricultural.

Poultry Imported to Iowa, January 2016

The Poultry Imported to Iowa report monthly by the Department of Agricultural.