| 1. |
- Ekstrand, Eva-Maria, 1985-, et al.
(författare)
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Identifying targets for increased biogasproduction through chemical and organicmatter characterization of digestate from full‑scale biogas plants : what remains and why?
- 2022
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Ingår i: Biotechnology for Biofuels and Bioproducts. - London, United Kingdom : BioMed Central. - 2731-3654. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: This study examines the destiny of macromolecules in different full-scale biogas processes. From previousstudies it is clear that the residual organic matter in outgoing digestates can have significant biogas potential,but the factors dictating the size and composition of this residual fraction and how they correlate with the residualmethane potential (RMP) are not fully understood. The aim of this study was to generate additional knowledge of thecomposition of residual digestate fractions and to understand how they correlate with various operational and chemicalparameters. The organic composition of both the substrates and digestates from nine biogas plants operating onfood waste, sewage sludge, or agricultural waste was characterized and the residual organic fractions were linked tosubstrate type, trace metal content, ammonia concentration, operational parameters, RMP, and enzyme activity.Results: Carbohydrates represented the largest fraction of the total VS (32–68%) in most substrates. However, inthe digestates protein was instead the most abundant residual macromolecule in almost all plants (3–21 g/kg). Thedegradation efficiency of proteins generally lower (28–79%) compared to carbohydrates (67–94%) and fats (86–91%).High residual protein content was coupled to recalcitrant protein fractions and microbial biomass, either from thesubstrate or formed in the degradation process. Co-digesting sewage sludge with fat increased the protein degradationefficiency with 18%, possibly through a priming mechanism where addition of easily degradable substrates alsotriggers the degradation of more complex fractions. In this study, high residual methane production (> 140 L CH4/kgVS) was firstly coupled to operation at unstable process conditions caused mainly by ammonia inhibition (0.74 mgNH3-N/kg) and/or trace element deficiency and, secondly, to short hydraulic retention time (HRT) (55 days) relative tothe slow digestion of agricultural waste and manure.Conclusions: Operation at unstable conditions was one reason for the high residual macromolecule content andhigh RMP. The outgoing protein content was relatively high in all digesters and improving the degradation of proteinsrepresents one important way to increase the VS reduction and methane production in biogas plants. Post-treatment
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| 2. |
- Bråkenhielm, Carl-Reinhold
(bidragsgivare, creator_code:cre_t)
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Kunskapsläget på kärnavfallsområdet 2022 : Samhället, tekniken och etiken
- 2022
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Rapport (populärvet., debatt m.m.)abstract
- Kärnavfallsrådet (Statens råd för kärnavfallsfrågor) är en tvärvetenskaplig kommitté som har i uppdrag att ge regeringen råd i frågor om använt kärnbränsle, kärnavfall och rivning av kärntekniska anläggningar, (M 1992:A Kärnavfallsrådet. Dir. 2018:18). I februari vartannat år ger Kärnavfallsrådet sin självständiga bedömning av det aktuella läget inom kärnavfallsområdet. Bedömningen presenteras i form av en kunskapslägesrapport. Syftet med rapporten är att upp-märksamma och beskriva frågor som Kärnavfallsrådet anser viktiga och att redogöra för rådets synpunkter i dessa. Kärnavfallsrådet överlämnar härmed till regeringen årets kunskapslägesrapport SOU 2022:7 Kunskapsläget på kärnavfallsområdet 2022 – Samhället, tekniken och etiken.Bakom denna rapport står samtliga ledamöter och sakkunniga i Kärnavfallsrådet. Kärnavfallsrådets vetenskapliga sekreterare Johanna Swedin har varit projektledare för arbetet med kunskapslägesrapporten.Rapporterna om kunskapsläget på kärnavfallsområdet åren 1998, 2001, 2004, 2007, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 och 2020 finns även tillgängliga i en engelsk version. Rådet kommer att publicera en engelsk översättning av årets rapport under våren 2022.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Karlsson, Linda, et al.
(författare)
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Dietary influence on the m. longissimus dorsi fatty acid composition of lambs in relation to protein source
- 2012
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Ingår i: Meat Science. - : Elsevier BV. - 0309-1740 .- 1873-4138. ; 91, s. 472-477
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Tidskriftsartikel (refereegranskat)abstract
- Dietary lipid effect, as a consequence of protein supplement, on lamb m. longissimus dorsi fatty acid composition was investigated, with emphasis on biohydrogenation intermediates. Crossbred lambs (White Swedish Landrace x Texel) were fed a barley-based diet without (CON) or with protein supplements including peas (PEA), rapeseed cake (RC) or hempseed cake (HC). The HC diet resulted in the highest muscle 22:6n-3 proportion, with the RC diet being similar (P < 0.05). Protein supplement did not affect the c9,t11 conjugated linoleic acid (CLA) proportion, however the HC diet increased some minor CIA isomers, including t10,c12 CIA (P < 0.05). The t10-18:1 and total trans-18:1 were lowest for the RC diet (P < 0.05). likely relating to rumen conditions and precursor availability. The saturated, monounsaturated and branched-chain fatty acids were largely unaffected by protein supplement. In conclusion, feeding the RC diet lowered the t10-18:1 and total trans-18:1 in meat, and modestly increased 22:6n-3 content. The direction of these changes would be beneficial, making the RC diet the preferred protein supplement; however the magnitude of the changes in the present experiment may not be sufficient to have an impact on human health. (C) 2012 Elsevier Ltd. All rights reserved.
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| 7. |
- Karlsson, Linda, et al.
(författare)
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Effects of increasing amounts of hempseed cake in the diet of dairy cows on the production and composition of milk
- 2010
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 4, s. 1854-1860
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Tidskriftsartikel (refereegranskat)abstract
- This study explored the potential for using seed cake from hemp (Cannabis sativa L.) as a protein feed for dairy cows. The aim was to evaluate the effects of increasing the proportion of hempseed cake (HC) in the diet on milk production and milk composition. Forty Swedish Red dairy cows were involved in a 5-week dose response feeding trial. The cows were allocated randomly to one of four experimental diets containing on average 494 g/kg of grass silage and 506 g/kg of concentrate on a dry matter (DM) basis. Diets containing 0 g (HC0), 143 g (HC14), 233 g (HC23) or 318 g (HC32) HC/kg DM were achieved by replacing an increasing proportion of compound pellets with cold-pressed HC. Increasing the proportion of HC resulted in dietary crude protein (CP) concentrations ranging from 126 for HC0 to 195g CP/kg DM for HC32. Further effects on the composition of the diet with increasing proportions of HC were higher fat and NDF and lower starch concentrations. There were no linear or quadratic effects on DM intake, but increasing the proportion of HC in the diet resulted in linear increases in fat and NDF intake, as well as CP intake (P < 0.001), and a linear decrease in starch intake (P < 0.001). The proportion of HC had significant quadratic effects on the yields of milk, energy-corrected milk (ECM) and milk protein, fat and lactose. The curvilinear response of all yield parameters indicated maximum production from cows fed diet HC14. Increasing the proportion of HC resulted in linear decreases in both milk protein and milk fat concentration (P = 0.005 and P = 0.017, respectively), a linear increase in milk urea (P < 0.001), and a linear decrease in CP efficiency (milk protein/CP intake; P < 0.001). In conclusion, the HC14 diet, corresponding to a dietary CP concentration of 157 g/kg DM, resulted in the maximum yields of milk and ECM by dairy cows in this study.
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| 8. |
- Karlsson, Linda, et al.
(författare)
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Growth performance of lambs fed different protein supplements in barley-based diets
- 2011
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 138, s. 125-131
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Tidskriftsartikel (refereegranskat)abstract
- This paper explores the potential of using locally produced protein sources in diets for growing lambs in northern Europe. The aim of the research was to evaluate the effects on lamb growth performance of peas, rapeseed cake and hempseed cake as protein supplements in barley-based diets. Forty-eight crossbred (White Swedish Landrace x Texel) ewe lambs were penned, forming experimental units allotted to one of four experimental diets. The lambs were on average 87 (SD = 9) days of age at the start of the eight-week continuous trial, during which their live weight (LW) was recorded weekly. The four experimental diets were barley-based, with 101 g hay/kg diet on a dry matter (DM) basis. The control diet (B-0). without protein supplement, contained 112 g crude protein (CP) and the calculated metabolisable energy (ME) value was 13.0 MJ/kg DM. The other diets contained peas (B-P), rapeseed cake (B-RC) or hempseed cake (B-HC) and had similar CP concentrations (160-162 g/kg DM), but varied in ME content (13.4, 13.4 and 12.2 MJ/kg DM, respectively). Rumen undegradable CP (RUP) was 231, 99, 298 and 291 g/kg CP, with an intestinal digestibility of 605, 707,528 and 307 g/kg RUP for the concentrates of barley, peas, rapeseed cake and hempseed cake, respectively. There were no significant differences in DM intake, which varied between 860 and 989 g/d, for the lambs on the different diets. However, CP intake was higher for lambs fed B-P and B-HC (P<0.001) and calculated ME intake was higher for lambs fed B-P (P=0.037) than for the other diets, among which there were no significant differences in these respects. Initial LW of the lambs did not differ significantly between treatments, but final LW was higher for lambs fed B-P and B-RC (P=0.029). Total gain and average daily gain were highest for the B-P treatment, followed by the B-RC treatment (P<0.001). Feed conversion (DM intake/LW gain) was more efficient for lambs fed B-P and B-RC, compared with the other treatments (P<0.001). No significant differences in growth performance or feed conversion were found between the B-0 and the B-HC treatments. In conclusion, supplementing barley-based diets with peas or rapeseed cake significantly improved growth performance of the lambs, but including hempseed cake did not. (C) 2010 Elsevier B.V. All rights reserved.
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| 9. |
- Karlsson, Linda
(författare)
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Hampfrökaka till mjölkkor och lamm
- 2010
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Ingår i: Nytt från Institutionen för norrländsk jordbruksvetenskap. Husdjur. - 1651-0801.
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Annan publikation (populärvet., debatt m.m.)
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| 10. |
- Karlsson, Linda
(författare)
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Hempseed cake as a protein feed for ruminants
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Increasing the use of locally produced protein feeds in ruminant production systems in northern Europe would be a valuable development. Hemp (Cannabis sativa L.) can be cultivated at high latitudes and cold-pressing the seeds to extract the oil produces a residue, hempseed cake (HC), with a high protein content. The overall aim of the studies presented in this thesis was to investigate the possibilities of using HC as a protein feed for ruminants. The in vitro gas production technique was developed further in order to estimate rumen protein degradation; the effective protein degradation (EPD) of HC determined by this method was low (0.33). When calculated from in situ crude protein (CP) disappearance, HC had a high EPD value (0.71-0.84) and a low in vitro intestinal digestibility (0.18-0.31) for the rumen undegradable protein (RUP). Moist heat treatment could be used to shift the site of CP digestion from the rumen to the small intestine. The highest temperature considered, 130°C, was associated with the largest amount of RUP and rumen undegraded amino acids with the highest intestinal digestibility. A high proportion of the neutral detergent fibre in HC was indigestible (0.85), which contributed to a low calculated metabolisable energy value (9.5 MJ/kg dry matter). Increasing the proportion of HC (0, 143, 233 or 318 g/kg dry matter) in the diet of dairy cows produced effects on the yields of milk, energy corrected milk and milk protein, fat and lactose that could be described by quadratic functions; the highest production was achieved by cows fed the diet containing 143 g HC/kg dry matter. There were linear decreases in the concentration of milk fat and protein and CP efficiency (milk protein/CP intake), and a linear increase in milk urea, with increasing proportions of HC. Supplementing barley-based diets with peas or rapeseed cake improved the growth performance of lambs, but inclusion of HC resulted in an average daily gain similar to that achieved with the control diet containing no protein supplement. The results from the studies underlying this thesis indicate that the nutritional value of HC will limit its use as a protein feed for ruminants.
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