Ammonia,Nitrous Oxide,Carbon Dioxide and Methane Emissions from Commercial Broiler Houses in Mediterranean Portugal

Limited data are available on ammonia (NH₃), nitrous oxide (N₂O), carbon dioxide (CO₂) and methane (CH₄) emissions from poultry housing in Mediterranean countries. The aim of the present study was to assess the NH₃, N₂O, CO₂ and CH₄ emission rates from commercial breeding hen and broiler houses under Mediterranean climate conditions. Research was conducted at one commercial breeding hen house and in two commercial broiler houses located in central Portugal. The environmental conditions, gas concentrations and ventilation rates were measured in the cold (8.0?±?2.1 °C) and hot (20.7?±?1.9 °C) season for the breeding hen house, whereas for the two broiler houses, measurements were made during one fattening cycle in the fall (17.3?±?1.7 °C) season. Results showed that the annual average emission rates for breeding hen and broiler houses were 0.52?±?0.27 and 0.06?±?0.01 for NH₃, 0.030?±?0.042 and 0.006?±?0.001 for N₂O, 169.6?±?56.2 and 58.0?±?15.1 for CO₂ and 0.092?±?0.131 and 0.0113?±?0.0002 g day^?1 bird^?1 for CH₄, respectively. The N₂O emission rates observed in breeding hen houses may have been overestimated, being higher than previously reported for Mediterranean countries.     

土壤添加沼渣对温室气体排放及小麦生长的影响

Digestate, the product obtained after anaerobic digestion of organic waste for biogas production, is rich in plant nutrients and might be used to fertilize crops. Wheat(Triticum spp. L.) was fertilized with digestate, urea, or left unfertilized and cultivated in the greenhouse for 120 d. Emissions of greenhouse gasses(carbon dioxide(CO_2), methane(CH_4), and nitrous oxide(N_2O)) were monitored and plant growth characteristics were determined at harvest. The digestate was characterized for heavy metals, pathogens, and C and N mineralization potential in an aerobic incubation experiment. No Salmonella spp., Shigella spp., or viable eggs of helminths were detected in the digested pig slurry, but the number of faecal coliforms was as high as 3.6 × 10~4colony-forming units(CFU) g-~(1)dry digestate. The concentrations of heavy metals did not surpass the upper limits established by US Environmental Protection Agency(EPA). After 28 d, 17% of the organic C(436 g kg~(-1)dry digestate) and 8% of the organic N(6.92 g kg~(-1)dry digestate)were mineralized. Emissions of CO_2 and CH_4 were not significantly affected by fertilization in the wheat-cultivated soil, but digestate significantly increased the cumulative N_2O emission by 5 times compared to the urea-amended soil and 63 times compared to the uncultivated unfertilized soil. It could be concluded that digestate was nutrient rich and low in heavy metals and pathogens, and did not affect emissions of CH_4 and CO_2 when applied to a soil cultivated with wheat, but increased emission of N_2O.     

A deterministic harvest scheduler using perfect bin-packing theorem

The use of heuristic techniques in forest planning has been promoted by the need to solve complex problems that cannot be solved using mixed integer programming. We proved that for merchantability standards ensuring the perfect bin-packing theorem (PBPT), the maximum volume that can be harvested annually equals the sum of the maximum MAI of the stands. The method accommodates optimality criteria at the stand level, regarded as maximum MAI, and at the forest level, regarded as maximum annual allowable cut. We scheduled the harvesting by adjusting the first fit decreasing algorithm (FFD) to the PBPT conditions. When PBPT conditions were not met, we developed a mixed integer programming solution to adjust the merchantability standards of the stands to the distributional requirements of the PBPT, an adjustment that ensured the optimal performance of the FFD. The adjusted FFD was compared with linear programming (LP) and simulated annealing (SA) using two harvesting ages (i.e., one based on MAI maximization and one determined as the minimal age) and the same set of spatial temporal constraints for three areas in north-eastern British Columbia, Canada. We found that the adjusted FFD performed 100 times faster than SA and for annual allowable cut (AAC) supplied results that were more homogenous and at least 10% greater than the AAC supplied by SA. Furthermore, the adjusted FFD seemed to be relatively insensitive to spatial constraints (i.e., adjacency), while SA displayed a 70% reduction in AAC in response to an increase in adjacency delay from 1 year to 20 years. The results suggest that both adjusted FFD and SA are impacted by the selection of the harvesting age, but the adjusted FFD could still outperform SA.     

Pathotypes of <Emphasis Type="Italic">Plasmodiophora brassicae</Emphasis> causing damage to oilseed rape in the Czech Republic and Poland

Winter oilseed rape (Brassica napus) is an important crop in the Czech Republic and Poland. Clubroot disease caused by the pathogen Plasmodiophora brassicae is a serious and still-growing problem for oilseed rape growers in both countries. The aim of this study was to evaluate the pathotype composition of P. brassicae populations from the Czech Republic and Poland, according to the three evaluation systems, and to determine soil inoculum loads for representative fields via traditional end-point PCR as well as quantitative PCR analysis. There were considerable differences between the populations of P. brassicae from both countries, and the number of pathotypes varied depending on the evaluation system and the threshold used to distinguish susceptible vs. resistant plant reactions. This is the first study comparing the effect of different thresholds. Using an index of disease (ID) of 25 % to distinguish susceptible vs. resistant reactions, there was a total of seven pathotypes identified based on the differentials of Williams, five with the system of Somé et al., and 18 with the European Clubroot Differential (ECD) set. However, based on a threshold of 50 %, there were nine pathotypes according to the evaluation system by Williams, four based on the differentials of Somé et al., and 15 with the ECD set. Changing of the thresholds led to the reclassification of some pathotypes. Several pathotypes were common in both countries. High amounts of pathogen DNA were found in many of the field soils analysed by quantitative PCR. There was a weak correlation between soil pH and infestation of P. brassicae for the Polish soils.     

Influence of carbohydrates on the interaction of procyanidin B3 with trypsin

The biological properties of procyanidins, in particular their inhibition of digestive enzymes, have received much attention in the past few years. Dietary carbohydrates are an environmental factor that is known to affect the interaction of procyanidins with proteins. This work aimed at understanding the effect of ionic food carbohydrates (polygalacturonic acid, arabic gum, pectin, and xanthan gum) on the interaction between procyanidins and trypsin. Physical-chemical techniques such as saturation transfer difference-NMR (STD-NMR) spectroscopy, fluorescence quenching, and nephelometry were used to evaluate the interaction process. Using STD-NMR, it was possible to identify the binding of procyanidin B3 to trypsin. The tested carbohydrates prevented the association of procyanidin B3 and trypsin by a competition mechanism in which the ionic character of carbohydrates and their ability to encapsulate procyanidins seem crucial leading to a reduction in STD signal and light scattering and to a recovery of the proteins intrinsic fluorescence. On the basis of these results, it was possible to grade the carbohydrates in their aggregation inhibition ability: XG > PA > AG ? PC. These effects may be relevant since the coingestion of procyanidins and ionic carbohydrates are frequent and furthermore since these might negatively affect the antinutritional properties ascribed to procyanidins in the past.     

Histological effects on the kidney,spleen, and liver of Nile tilapia Oreochromis niloticus fed different concentrations of probiotic Lactobacillus plantarum

Tropical Animal Health and Production - The aims of this study were to evaluate the inclusion of different concentrations of Lactobacillus plantarum in Nile tilapia diet and to verify histological...     

Changes in feed consumption and water intake among broiler chickens subjected to melatonin treatment during the hot-dry season

Tropical Animal Health and Production - The experiment was conducted to evaluate changes in feed consumption and water intake among broiler chickens subjected to melatonin treatment during the...