Broiler production is a prime example of high density animal production. Broilers are often grown in production houses containing 20 000 birds or more at densities of 0.06 m 2 per bird. Broiler litter typically contains 4 to 6 % nitrogen, much of which is in the NH 3 or NH 4 + form. The mixture of litter and manure is effectively a nitrogen storehouse. Under the proper conditions, a considerable quantity of this nitrogen will be released as ammonia (Carr et al., 1990). Many factors, such as season of the year, ambient temperature and humidity, bird health, and management practices can influence ammonia volatilization from broiler rearing facilities (Coufal, 2005). Ammonia is formed from the breakdown of nitrogenous waste products in poultry manure (undigested proteins and uric acid) by exogenous enzymes produced by microorganisms. Factors that exhibit direct control over these processes have been identified as pH, temperature, and moisture (Elliot and Collins, 1982). Ammonia release is depressed at pH < 7 but is very high at pH > 8 (Parker et al., 2005). Therefore, in a commercial broiler grow-out facility, pH would seldom be a factor determining NH 3 volatilization since the pH of broiler litter is Supported by Slovak-Norwegian Project No. 2032051 "Reducing Environmental Impact from Large-Scale Animal Production in Slovak Republic". ABSTRACT:The research reported in this article attempts to address the ammonia problem by quantifying the effect of several variables on ammonia concentrations and emissions. These variables include litter temperature, litter age and ventilation rate. Data was collected in a commercial tunnel-ventilated grow-out facility with deep litter, designed for 25 000 broilers, during 6 consecutive flocks. Birds were housed from hatching to approximately 40 days of age. Litter temperature and litter age were positively correlated (P < 0.0001) with the production of ammonia gas. The amount of ammonia emissions increased with the litter age (P < 0.0001) as a consequence of both the increased ammonia concentration and the ventilation rate (P < 0.0001). The lowest concentrations of NH 3 were observed in a "summer" period, although ammonia emissions tended to be higher just in summer months because of a higher ventilation rate. The elevated levels of ammonia in winter were attributed to the lower ventilation rate during cold weather. After the evaluation of ammonia emissions it can be concluded that during the grow-out period of broilers kept on renewed litter there is an average loss of 6.18 g ammonia per bird and/or 0.043 kg of ammonia per bird yearly. The increase in litter temperature during grow-out periods is a process which could be controlled to prevent excessive ammonia volatilization from housing facilities.

AbstrAct:The quantification of emissions of greenhouse gases from human activities is of prime importance for determining the importance of their effect on the environment. The aim of this study was to test a hypothesis that the interior concentration and emission of carbon dioxide in chicken housing is impacted by the age of animals and season of fattening period. Carbon dioxide (CO 2 ) concentrations and emissions were assessed over six fattening periods in total. The major part of CO 2 seemed to have its origin in bird respiration with assumed production of approx. 147 kg of CO 2 /h. CO 2 emission was most affected by chickens towards the end of the grow-out period (P < 0.001) taking dominance over the process of natural gas burning by heaters. The mean CO 2 emission from the chicken house ranged between 120 and 247 kg/h in the first quarter of periods and between 325 and 459 kg/h in the last ones. The heaters could be theoretically a possible source of approx. 39 kg each hour if they worked continuously. CO 2 emissions were considerably more affected by ventilation rate (P < 0.001) than by CO 2 concentration in the indoor air.

The aim of this experiment was to analyze the changes of ammonia production and greenhouse gases in frequent type of stables for dairy cows in winter. Two analyzed stables were situated side by side, one of which is after reconstruction of housing and ventilation technology and the second stable remained in original state. Variances of the mass concentration of gases differed significantly (P &lt; 0.05), and the production of all gases monitored in winter was higher in the original stable. The average ammonia production was 2.45 &plusmn; 1.9 mg/m³in the reconstructed stable, while in the original stable it was 5.1 &plusmn; 2.7 mg/m³. Average CO₂ production was nearly twice higher in the unreconstructed building, namely 2,045.5 &plusmn; 862.3 mg/m³, while in the renovated facility it was 1,254.2 &plusmn; 416.2 mg/m³(P &lt; 0.05). The described type of reconstruction provides increased comfort for animals, which gives rise to a significant increase in production parameters, but also allows up to twice the reduction of hazardous pollutants such as CO₂ and ammonia

The aim of this experiment was to analyse the influence of climatic factors on the thermal performance of separated liquid manure. The samples of organic bedding were collected from the lying area of dairy housing and preparatory store. The measurement of properties of recycled manure solids (RMS) was carried out in laboratory conditions. Samples were examined with determining the temperature effect on the thermal conductivity λ of 'dry' separated liquid manure (with a dry matter content of 60%) and 'wet' liquid manure (with a dry matter content of 26%), in air temperatures ranging from 0 °C to 40 °C. Subsequently, the thermal resistance of three selected types of cows lying structures was calculated for winter and summer boundary values. Based on the results of thermal conductivity and thermal resistance, it was observed that dry separated liquid manure as an alternative bedding has, in low temperature (up to 5 °C), the most suitable thermal performance if it is maintained in a dry condition (with a dry matter content of 60%). With increasing temperature (above 20 °C) and increasing humidity of bedding (below 26%), thermo-technical properties get worse; however, when comparing the thermal resistance of the cow bed structure with sandwich mattresses with a 50 mm layer of organic bedding and the deep cubicle filled with 200 mm of organic bedding, the thermal resistance of floor structure decreases by 7.6% or 18.4%, respectively. With a proper handling of the recycled organic bedding, it is possible to use its economic advantages.

The aim of the experiment was to determine the concentrations of harmful gases production in the dairy housing and to compare the difference of measured data in terms of frequency of manure removal. Measuring the concentration of ammonia, methane and carbon dioxide was carried out in summer in three-day cycles when produced excrements were removed every day at 19:00 o'clock, and in three-day cycles when removing of excreta was carried out twice a day, in the morning and evening at 5:00 and 19:00 o'clock. Microclimatic conditions during the experiment were at a comparable level, ambient temperature was maintained at about 29 °C and relative humidity was 64 %. By comparing the obtained values of production in terms of frequency of waste removal, it has been shown that for removing twice a day, the production of ammonia, carbon dioxide, methane was higher than under manure removal only once a day. Keywords: ammonia, dairy housing, manure removal Abstrakt Cieľom experimentu bolo zistiť produkciu koncentrácií škodlivých plynov v objekte pre ustajnenie dojníc a porovnať rozdiel nameraných údajov z hľadiska frekvencie odstraňovania hnoja. Meranie koncentrácie amoniaku, metánu a oxidu uhličitého prebiehalo v letnom období v trojdenných cykloch, kedy vyprodukované exkrementy boli odstraňované raz za deň o 19:00 hodine a v trojdenných cykloch, kedy odstraňovanie exkrementov bolo vykonávané dvakrát za deň, ráno o 5:00 a večer o 19:00 hodine. Mikroklimatické podmienky vzduchu počas trvania experimentu boli 1262Journal of Central European Agriculture, 2013, 14(4), p.1262-1269 DOI: 10.5513/JCEA01/14.4.1340 1279 Journal of Central European Agriculture, 2013, 14(4), p.1279-1286 DOI: 10.5513/JCEA01/14.4.1340 na zrovnateľnej úrovni, teplota prostredia sa udržovala na cca 29°C a relatívna vlhkosť vzduchu 64%. Porovnaním získaných hodnôt produkcie z hľadiska frekvencie odstraňovania exkrementov bolo preukázané, že pri počte odstraňovania 2x za deň bola produkcia amoniaku, oxidu uhličitého aj metánu vyššia, ako to bolo pri vyhŕňaní len raz denne.