Martin Dobeic

A farm-scale study on the use of clinoptilolite zeolite and De-Odorase® for reducing odour and ammonia emissions from broiler houses

Intensive poultry farms are frequently the subject of odour complaints and are also known emitters of ammonia. In this paper an experiment is described which compared the effectiveness of two abatement compounds, clinoptilolite and De-Odorase®, when used in broiler production. Two sites were used which had almost identical buildings, each with two rooms, and the same strain of bird. Clinoptilolite was used on one site and De-Odorase® on the other. Once a week ventilation rate, ammonia concentration and odour concentration were measured, to determine the effects of the additives. We also measured temperature, relative humidity and carbon dioxide concentration to confirm that the control and test rooms had similar micro-climates. In the room treated with clinoptilolite the ammonia concentration was statistically significantly higher than in the control and the total mass of ammonia emitted was 50% greater. In the De-Odorase® experiment the mean ammonia concentration in the treated room in the final week was 38% lower than in the control and the total mass of ammonia emitted from the treated room was 50% lower. There was no statistically significant reduction in the odour concentration or odour emission rate for either of the additives used.

A farm scale study on the use of De-Odorase® for reducing odour and ammonia emissions from intensive fattening piggeries

Abstract An experiment was mounted at a large fattening piggery in Slovenia, during which different groups each of 600 weaned pigs were housed and grown in different fattening rooms for 60 days (from age 24 days to age 84 days). All rooms were mechanically ventilated and had fully-slatted floors with slurry channels beneath. De-Odorase ® † was added to the diet of the treated groups of pigs at the rates recommended by the suppliers, e.g. for grower feed, 65 g/t. De-Odorase ® was also added daily (3·2 g suspended in 10 l of water) to the upstream ends of the slurry channels. Once a week, the ammonia concentration in the air inside each fattening room was measured at each of four positions, using Drager tubes, and the ventilation rate was computed from the cross-sectional area of each fan outlet and the average velocity of the air emerging from each. Also, air samples were taken from immediately outside three of the fans serving each room, and their odour concentrations were measured by olfactometry. Hence, weekly values of emission rates of both ammonia and odour could be calculated. Ammonia concentration was significantly lower ( P = 0·001) in the De-Odorase ® -treated buildings than in the control buildings. The average reduction in ammonia concentration over a 7 week period was 26%. Ammonia emission rate was also reduced by 26% through the use of the additive. This reduction was significant at P = 0·048. Neither odour concentration nor odour emission rate was significantly reduced through the use of the additive. The additive did not significantly influence the rate of live-weight gain by the pigs.

Prevalence of Pigeon Circovirus Infections in Feral Pigeons in Ljubljana, Slovenia

SUMMARY. Pigeon circovirus (PiCV) was detected by real-time PCR in cloacal swabs, pharyngeal swabs, and serum samples taken from 74 feral pigeons (Columba livia var. domestica) that were caught at various locations in the city of Ljubljana, Slovenia. PiCV infections were detected in the majority of the tested birds. The highest (74.3%) detection rate was observed in the cloacal swabs and the lowest (31.1%) in serum samples. PiCV DNA was more readily detected in the cloacal swabs, pharyngeal swabs, and serum samples of birds younger than 1 yr. Molecular analysis of partial open reading frame V1 sequences showed that PiCV strains detected in feral pigeons share high nucleotide and amino acid sequence identities with PiCV strains detected in ornamental, racing, meat, and feral pigeons. RESUMEN. Reporte de Caso—Prevalencia de las infecciones asociadas con circovirus de las paloma en las palomas en libertad en Ljubljana, Eslovenia. El circovirus de las palomas (PiCV) fue detectado por PCR en tiempo real en hisopos cloacales, hisopos faríngeos y en muestras de suero tomadas de 74 palomas en libertad (Columba livia var. domestica) que fueron capturadas en distintos lugares de la ciudad de Ljubljana, Eslovenia. Se detectó la infección por el circovirus de las palomas en la mayoría de las aves analizadas. El porcentaje de detección más alto (74.3%) se observó en los hisopos cloacales y la más baja (31.1%) en muestras de suero. El ADN del circovirus de las palomas fue detectado más fácilmente en los hisopos cloacales, hisopos faríngeos y en muestras de suero de las aves menores de un año. El análisis molecular de las secuencias parciales del marco de lectura continua V1 mostró que las cepas de circovirus detectadas en las palomas en libertad comparten altas identidades en las secuencias de nucleótidos y de aminoácidos con las cepas de circovirus detectadas en palomas ornamentales, de competencia, productoras de carne y salvajes.

Degradation and dissipation of the veterinary ionophore lasalocid in manure and soil

Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It is excreted from the treated animals mostly in its active form and enters the environment with the use of contaminated manure on agricultural land. To properly assess the risk that lasalocid poses to the environment, it is necessary to know its environmental concentrations as well as the rates of its degradation in manure and dissipation in soil. These values are still largely unknown. A research was undertaken to ascertain the rate of lasalocid degradation in manure under different storage conditions (aging in a pile or composting) and on agricultural soil after using lasalocid-contaminated manure. The results have shown that there is considerable difference in lasalocid degradation between aging manure with no treatment (t1/2=61.8±1.7 d) and composting (t1/2=17.5±0.8 d). Half-lives in soil are much shorter (on average 3.1±0.4 d). On the basis of the measured concentrations of lasalocid in soil after manure application, we can conclude that it can potentially be harmful to soil organisms (PEC/PNEC ratio of 1.18), but only in a worst-case scenario of using the maximum permissible amount of manure and immediately after application. To make certain that no harmful effects occur, composting is recommended.

Photocatalytic disinfection of surfaces with copper doped Ti02 nanotube coatings illuminated by ceiling mounted fluorescent light

High economic burden is associated with foodborne illnesses. Different disinfection methods are therefore employed in food processing industry; such as use of ultraviolet light or usage of surfaces with copper-containing alloys. However, all the disinfection methods currently in use have some shortcomings. In this work we show that copper doped TiO2 nanotubes deposited on existing surfaces and illuminated with ceiling mounted fluorescent lights can retard the growth of Listeria Innocua by 80% in seven hours of exposure to the fluorescent lights at different places in a food processing plant or in the laboratory conditions with daily reinocuation and washing. The disinfection properties of the surfaces seem to depend mainly on the temperature difference of the surface and the dew point, where for the maximum effectiveness the difference should be about 3 degrees celsius. The TiO2 nanotubes have a potential to be employed for an economical and continuous disinfection of surfaces.

Surface deposited one-dimensional copper-doped TiO2 nanomaterials for prevention of health care acquired infections

Bacterial infections acquired in healthcare facilities including hospitals, the so called healthcare acquired or nosocomial infections, are still of great concern worldwide and represent a significant economical burden. One of the major causes of morbidity is infection with Methicillin Resistant Staphylococcus aureus (MRSA), which has been reported to survive on surfaces for several months. Bactericidal activity of copper-TiO2 thin films, which release copper ions and are deposited on glass surfaces and heated to high temperatures, is well known even when illuminated with very weak UVA light of about 10 μW/cm2. Lately, there is an increased intrerest for one-dimensional TiO2 nanomaterials, due to their unique properties, low cost, and high thermal and photochemical stability. Here we show that copper doped TiO2 nanotubes produce about five times more ·OH radicals as compared to undoped TiO2 nanotubes and that effective surface disinfection, determined by a modified ISO 22196:2011 test, can be achieved even at low intensity UVA light of 30 μW/cm2. The nanotubes can be deposited on a preformed surface at room temperature, resulting in a stable deposition resistant to multiple washings. Up to 103 microorganisms per cm2 can be inactivated in 24 hours, including resistant strains such as Methicillin-resistant Staphylococcus aureus (MRSA) and Extended-spectrum beta-lactamase Escherichia coli (E. coli ESBL). This disinfection method could provide a valuable alternative to the current surface disinfection methods.