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Moset V.,Animal Technology and Research Center | Torres A.G.,Polytechnic University of Valencia | Estelles F.,Polytechnic University of Valencia | Cerisuelo A.,Animal Technology and Research Center
ASABE - International Symposium on Air Quality and Waste Management for Agriculture 2010 | Year: 2010

Gas emission and the evolution of nutrient composition of pig slurry were evaluated comparing two types of slurry from fattening pigs: with a previous solid separation (SS) and raw slurry (RS). Slurry was obtained at the end of a 19-week fattening period from an experimental pig unit. Six 100 L vessels of slurry were filled, three of them with RS and three of them after the solid-liquid separation (SS). Methane, carbon dioxide, nitrous oxide and water vapor emission were registered during 24-h periods using a photoacoustic monitor. Measurements were conducted once per week during 15 weeks. Samples of slurry were taken fortnightly and analyzed for total solids, volatile solids, total and dissolved Kjeldhal nitrogen, volatile fatty acids (VFA), dissolved chemical oxygen demand (CODd) and pH. Dissolved chemical oxygen demand, VFA and carbon dioxide emission increased on week 3 of the study, especially in RS, indicating an important acidogenic and acetogenic activity during this time. Methane emission was minimal during the first 6 weeks of storage and reached the maximum levels between week 9 and 12, being 0.099 mg h-1 gCOD-1 initial in SS and 0.152 mg h -1 gCOD-1 initial in RS (p<0.001). Thus, from week 9 of storage period, decomposition of organic matter was mainly due to methanogenic bacteria. Between treatments, RS showed better anaerobic conditions than SS and thus, greater methane and nitrous oxide emissions. Source


Moset V.,Animal Technology and Research Center | Torres L.,Animal Technology and Research Center | Torres A.G.,Polytechnic University of Valencia | Cerisuelo A.,Animal Technology and Research Center
ASABE - International Symposium on Air Quality and Waste Management for Agriculture 2010 | Year: 2010

The influence of dietary factors on manure composition and gas emission was studied in pigs. A total of 128 pigs weighing 63.1±9.67 kg were divided by weight and sex into two dietary treatments: one high (HD) and other low (LD) in energy and lysine, but maintaining lysine:energy ratio (LD; 13.97 MJDE kg -1, 0.72 g lysine MJ -1DE and HD; 14.39 MJDE kg -1, 0.77 g lysine MJ -1DE). Average daily gain and daily feed intake were controlled during 41 days (phase 1). After the productive study, 12 females of 103.3±3.15 kg (6 per treatment) were selected and housed individually (phase 2). Feces and urine (slurry) were collected during 3 consecutive days. After collection, slurry was pooled by treatment and six 30L buckets (3 per treatment) were filled and stored during a 11-day period. Initial and final composition (dry matter (DM), organic matter (OM), total Kjeldahl nitrogen (TKN), volatile fatty acids (VFA) and pH) were analyzed. Gas emission was measured using a photoacoustic gas monitor. Both, males and females fed HD diets grew more efficiently than pigs fed LD diets (p<0.05). Slurry from pigs fed LD diets showed greater DM, OM, TKN and VFA concentrations and a lower final pH than slurry from HD pigs (p<0.05). Carbon dioxide and ammonia emission did not differ between treatments. Thus, the combination of high energy and lysine content used in the present study for growing pigs (HD) led to a more efficient growth and a lower nutrient concentration in slurry, with no significant differences in gas emission. Source

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