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Bruun S.,Copenhagen University | Jensen L.S.,Copenhagen University | Khanh Vu V.T.,National Institute of Animal science | Sommer S.,University of Southern Denmark
Renewable and Sustainable Energy Reviews | Year: 2014

There are a number of advantages to small-scale biogas production on farms, including savings on firewood or fossil fuels and reductions in odour and greenhouse gas emissions. For these reasons, governments and development aid agencies have supported the installation of biogas digesters. However, biogas digesters are often poorly managed and there is a lack of proper distribution systems for biogas. This results in methane being released inadvertently through leaks in digesters and tubing, and intentionally when production exceeds demand. As methane has a global warming potential 25 times greater than that of carbon dioxide, this compromises the environmental advantages of digesters. Calculations performed in this paper indicate that the break-even point at which the released methane has as great an impact on global warming as the fuel that has been replaced occurs when between 3% and 51% of the produced biogas is released, depending on the type of fuel that has been replaced. The limited information available as regards methane leaking from small-scale biogas digesters in developing countries indicates that emissions may be as high as 40%. With the best estimates of global numbers of small-scale digesters and their biogas production, this corresponds to methane losses of 4.5 Tg yr -1 or about 1% of global emissions or 10% as much as emissions from rice production. Further poliferation of small-scale digesters could therefore contribute significantly to global emissions of methane. It is therefore important that governments and development aid agencies place stricter requirements on digester maintenance and biogas handling before incentives are created and legislation introduced for the installation of small-scale biogas digesters. © 2014 Elsevier Ltd. Source

Giang H.H.,Ministry of Agriculture and Rural Development | Viet T.Q.,National Institute of Animal science | Ogle B.,Swedish University of Agricultural Sciences | Lindberg J.E.,Swedish University of Agricultural Sciences
Asian-Australasian Journal of Animal Sciences | Year: 2011

Two experiments were conducted to investigate the effect of dietary supplementation of Bacillus, Saccharomyces and lactic acid bacteria (LAB) on performance and nutrient digestibility in grower and finisher pigs. In Exp. 1, 80 pigs (32 females and 48 males), 28.7±0.9 kg body weight (BW), were randomly divided into 4 treatment groups balanced for sex and weight (5 pigs per pen, 4 pens per treatment). They were fed one of four diets: a basal grower (20-50 kg BW) and finisher (>50 kg BW) diet without any addition of probiotic or antibiotic (diet C), the basal diet supplemented with Bacillus subtilis H4 (diet B), diet B supplemented with Saccharomyces boulardi Sb (diet BS) and diet BS supplemented with a LAB complex (diet BSL). The LAB complex consisted of Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, and Lactobacillus fermentum NC1. In Exp. 2, 16 male pigs, 29.2±0.8 kg BW, were kept in individual pens and divided into 4 groups (4 pigs in each group). All 4 groups were given exactly the same growing-period diets (diet C, B, BS and BSL) as in Exp 1. The total faeces and urine were collected during 5 days (day 20-24) to determine nitrogen retention and total tract digestibility. In the growing period, average daily feed intake (ADFI), average daily gain (ADG) and feed conversion ratio (FCR) were not affected by diet B and BS (p>0.05), but ADG increased (+5.9%) (p<0.05) and FCR improved (+5.9%) (p<0.05) on diet BSL compared with the control, although ADFI was not different (p>0.05). Digestibility of crude protein and organic matter was higher (p<0.05) in diet BSL and digestibility of crude fibre was higher (p<0.05) in diet BS and BSL than in diet C. Nitrogen retention was not affected by diet (p>0.05). The faecal LAB counts were increased in grower pigs fed diet BSL (p<0.05) and faecal E. coli counts were decreased in pigs fed diets BS and BSL (p<0.05). In the finishing period, no effects of diet were found in ADFI, ADG, FCR, nutrient digestibility, and nitrogen retention (p>0.05). Faecal LAB and E. coli counts in the finisher pigs were not affected by diet (p>0.05). In conclusion, the current study demonstrates that a mixture of bacteria and yeast has the potential to be used as a probiotic dietary supplement in grower pigs. Source

Jorgensen H.,University of Aarhus | Prapaspongsa T.,Mahidol University | Vu V.T.K.,National Institute of Animal science | Poulsen H.D.,University of Aarhus
Journal of Animal Science and Biotechnology | Year: 2013

Modern pig production contributes to many environmental problems that relate to manure, especially in areas with highly intensive production systems and in regions like Asia where the regulative control is not effective. Therefore, the objective of this study was to use three different pig diets varying in dietary protein, fibre and fat as representative for Danish (DK), Thai (TH) and Vietnamese (VN) pig production to develop and evaluate different approaches to predict/calculate excretion from growing pigs in comparison with the experimentally determined values.Nine female growing pigs were used in a digestibility and balance experiment. Excretion of dry matter (DM), nitrogen (N), phosphorus (P) and carbon (C) of the experimental diets were determined.Due to the highest dietary fibre content, VN had the lowest digestibility of N, P and C (73, 49, and 73%, respectively) compared with the DK and TH pig diets. From the known diet composition using standard table values on chemical and nutrient digestibly, high accuracy (bias) and low variation was found and the results could be used for prediction on chemical composition and excretion in faeces and urine in growing pigs. Calculation based on standard values regarding nutrient retention in the pig body as used in the Danish manure normative system (DMNS) showed likewise to be quite useful for quantifying the total excretion of N and P.Overall, the results demonstrate that simple models that require cheap and normally available information on dietary nutrients can give useful information on nutrient excretion in growing pigs. © 2013 Jørgensen et al.; licensee BioMed Central Ltd. Source

Giang H.H.,Ministry of Agriculture and Rural Development | Viet T.Q.,National Institute of Animal science | Ogle B.,Swedish University of Agricultural Sciences | Lindberg J.E.,Swedish University of Agricultural Sciences
Livestock Science | Year: 2012

Growth performance, digestibility, gut environment and health status were studied in weaned piglets (26-28. days of age) fed a diet without (C) or with supplementation of bacteria and a yeast (diets L, LB and LBS). Diet L was supplemented with a lactic acid bacteria (LAB) complex (Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, and L. fermentum NC1), diet LB with the LAB complex and Bacillus subtilis H4, and diet LBS with the LAB complex, B. subtilis H4 and Saccharomyces boulardii Sb. Piglets fed diets L, LB and LBS had higher feed intake and daily gain, lower feed conversion ratio, higher ileal and total tract digestibility, and had a lower incidence of diarrhoea and a lower faecal score than piglets fed diet C (P < 0.01). Diets L, LB and LBS increased the intestinal LAB population and organic acid concentrations, and reduced E. coli counts. Supplementation with B. subtilis H4 and S. boulardii Sb resulted in higher digestibility than when supplementing with the LAB complex alone. Supplementation with S. boulardii Sb resulted in lower incidence of diarrhoea and lower faecal score than supplementation with the LAB complex alone or together with B. subtilis H4. The LAB complexes used in the current study had probiotic properties and could be used to improve the health status of weaned piglets under Vietnamese conditions. © 2011 Elsevier B.V. Source

Fournie G.,Royal Veterinary College University of London | Guitian J.,Royal Veterinary College University of London | Desvaux S.,CIRAD - Agricultural Research for Development | Mangtani P.,London School of Hygiene and Tropical Medicine | And 7 more authors.
PLoS ONE | Year: 2012

Wet markets are common in many parts of the world and may promote the emergence, spread and maintenance of livestock pathogens, including zoonoses. A survey was conducted in order to assess the potential of Vietnamese and Cambodian live bird markets (LBMs) to sustain circulation of highly pathogenic avian influenza virus subtype H5N1 (HPAIV H5N1). Thirty Vietnamese and 8 Cambodian LBMs were visited, and structured interviews were conducted with the market managers and 561 Vietnamese and 84 Cambodian traders. Multivariate and cluster analysis were used to construct a typology of traders based on their poultry management practices. As a result of those practices and large poultry surplus (unsold poultry reoffered for sale the following day), some poultry traders were shown to promote conditions favorable for perpetuating HPAIV H5N1 in LBMs. More than 80% of these traders operated in LBMs located in the most densely populated areas, Ha Noi and Phnom Penh. The profiles of sellers operating at a given LBM could be reliably predicted using basic information about the location and type of market. Consequently, LBMs with the largest combination of risk factors for becoming virus reservoirs could be easily identified, potentially allowing control strategies to be appropriately targeted. These findings are of particular relevance to resource-scarce settings with extensively developed LBM systems, commonly found in South-East Asia. © 2012 Fournié et al. Source

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