1,169 research outputs found
Abbattimento degli inquinanti dal biogas: rimozione dei silossani mediante carboni attivi
No full textIl documento riporta la descrizione delle attività condotte con l’obiettivo di individuare sistemi adatti alla rimozione dei silossani dal biogas. E’ riportata la descrizione dell’apparato sperimentale e dei materiali utilizzati, della procedura sperimentale seguita e dei risultati ottenuti. Nello specifico dopo un primo screening su diversi materiali (silica gel, zeoliti, carboni attivi) si è valutato che i carboni attivi mostrassero le migliori performances in termini di quantità di silossano rimosso, per cui tutti gli ulteriori studi sono stati condotti su un numero selezionato di carboni attivi commerciali, con diverse caratteristiche. In particolare è stata calcolata la capacità di adsorbimento dei vari materiali (definita come massa di silossano rimossa/massa di carbone utilizzato) al variare di alcuni parametri (massa di carbone utilizzata, granulometria del carbone, concentrazione del silossano in ingresso al trattamento). Tutte le prove sono state condotte utilizzando come gas di alimentazione azoto inquinato con un silossano, per cui ulteriori test si renderanno necessari per valutare gli effetti legati alla presenza della CO2 e degli altri inquinanti presenti nel biogas (in particolare H2S), che tipicamente possono competere nell’adsorbimento su carboni attivi
GREENHOUSE GAS EMISSIONS RELATED TO MILK PRODUCTION OF DAIRY COWS
No full textWith global emissions estimated at 7.1 Gt CO2 eq per annum, livestock represents 14.5% of all human-induced emissions and it is considered to be the largest source of greenhouse gas (GHG) emissions from the agricultural sector. However, livestock can contribute to convert nutrients from plant biomass into animal-sourced foods, which are rich in essential macro and micronutrients in the form of milk and meat, thereby utilizing resources that cannot otherwise be consumed by humans. Livestock also contributes to global food security and poverty reduction, providing regular income to producers. To achieve a sustainable supply of animal origin food, farmers need, therefore, to identify strategies, in terms of livestock management and feeding, forage systems and feed growing practices, that make the best use of available resources and minimize the potential environmental impact. The studies of the PhD thesis were mainly developed inside the Life project “Forage4Climate”, a four years project, aimed at demonstrating that forage systems connected to milk production can promote climate change mitigation. The aim of the PhD thesis was the evaluation of GHG emission, related to dairy cattle milk production. Specific aims were: • to identify and evaluate the most common forage systems adopted in dairy cow farms in the Po plain, selecting the systems that can improve milk production and soil carbon (C) sequestration reducing emissions per kg of milk; • to evaluate commercial diets related to these different forage systems, in order to directly assess their digestibility, milk and methane (CH4) production; • to identify, through a survey analysis, the main ingredients used in the total mixed ration (TMR) of high producing lactating cows, in order to assess the best diet composition that can lead to high feed efficiency (FE) and low global warming potential (GWP) at commercial farms scale; • in a future perspective of circular economy, to study the exploitation of different inedible human by-products as growing substrates for Hermetia Illucens larvae, in order to substitute soybean meal (SBM) in the livestock diets with insect proteins. A total of 46 dairy cattle farms in Lombardy, Piedmont and Emilia-Romagna were visited, in order to map the main forage systems adopted in each area and to characterize them for GHG emission related to milk production (FPCM, fat and protein corrected milk), and soil organic C stock. The evaluation of environmental impact, in terms of GWP, related to the different forage systems was carried out though a Life Cycle Assessment (LCA) method, using the Software SIMAPRO. Six forage systems based on different forages were identified. The main results in terms of GHG per unit milk were: - CONV - Conventional corn silage system: 1.37 kg CO2 eq/kg FPCM (SD 0.26) - HQFS - High quality forage system: 1.18 kg CO2 eq/kg FPCM (SD 0.13) - WICE - Winter cereal silage system: 1.44 kg CO2 eq/kg FPCM (SD 0.43) - MIXED - Mixed less intensive system: 1.36 kg CO2 eq/kg FPCM (SD 0.26) - PR FRESH- Hay and fresh forage system for Parmigiano Reggiano PDO cheese production: 1.51 kg CO2 eq/kg FPCM (SD 0.23) - PR DRY- Hay system for Parmigiano Reggiano PDO cheese production: 1.36 kg CO2 eq/kg FPCM (SD 0.19). The HQFS system registered the lowest value for GWP, mainly due to the higher milk production per cow (daily FPCM/head). More intensive systems, such as HQFS, confirmed that milk production per cow is negatively related to the impact per kilogram of product, as highlighted also by a PROC GLM analysis. The HQFS system also resulted to be more sustainable, in terms of feed self-sufficiency, as it provided a high amount of dry matter (DM) per hectare, consisting of high digestible forages. Despite the lowest value for GWP, the forage system identified as HQFS showed the lowest organic C soil density: 5.6 kg/m2 (SD 1.1). On the contrary, PR FRESH showed the highest value in terms of organic C density in the soil: 9.7 kg/m2 (SD 2.2), compared with an average of 6.7 kg/m2 (SD 0.88) for the other systems. Further investigations are needed to consider environmental sustainability over a wider spectrum. Enteric CH4 was the main contributor to GWP for all forage systems: on average 45.6% (SD 3.89). For this reason, an in vivo evaluation of CH4 and milk production of lactating dairy cows fed four different diets, obtained from the forage systems identified, was performed. Also digestibility of the diets, energy and nitrogen (N) balance were assessed. Four pairs of Italian Friesian lactating cows were used in a repeated Latin Square design, using individual open circuit respiration chambers to determine dry matter intake (DMI), milk production and CH4 emission and to allow total faeces and urine collection for the determination of N and energy balances. Four diets, based on the following main forages, were tested: corn silage (49.3% DM; CS), alfalfa silage (26.8% DM; AS), wheat silage (20.0% DM; WS), hay-based diet (25.3% DM of both alfalfa and Italian ryegrass hays; PR) typical of the area of Parmigiano Reggiano cheese production. Feeding cows with PR diet significantly increased DMI (23.4 kg/d; P=0.006), compared with the others (on average, 20.7 kg/d), while this diet resulted to be the least digestible (e.g. DM digestibility=64.9 vs 71.7% of the other diets, on average). This is probably the reason why, despite higher DMI of cows fed PR diet, the animals did not show higher production, both in terms of milk (kg/d) and energy corrected milk (ECM; kg/d), compared with the other treatments. The urea N concentration was higher in milk of cows fed WS diet (13.8) and lower for cows fed AS diet (9.24). This was also correlated to the highest urinary N excretion (g/d) for cows fed WS diet (189.5 vs 147.0 on average for the other diets). The protein digestibility was higher for cows fed CS and WS diets (on average 68.5%) than for cows fed AS and PR (on average 57.0%); the dietary soybean inclusion was higher for CS and WS than AS and PR. The higher values for aNDFom digestibility were obtained for CS (50.7%) and AS (47.4%) diets. The rumen fermentation pattern was affected by diet; in particular PR diet, characterized by a lower content of NFC and a higher content of aNDFom as compared to CS diet, determined a higher rumen pH and decreased propionate production as compared to CS. Feeding cows with PR diet increased the acetate:propionate ratio in comparison with CS (3.30 vs 2.44 for PR and CS, respectively). Ruminal environment characteristics (i.e higher pH and higher acetate: propionate ratio), together with increased DMI, led cows fed PR DRY diet to have greater (P=0.046) daily production of CH4 (413.4 g/d), compared to those fed CONV diet (378.2 g/d). However, no differences were observed when CH4 was expressed as g/kg DMI or g/kg milk. Hay based diet (PR) was characterized by the lowest digestible and metabolizable energy contents which overall determined a lower NEL content for PR than CS diet (1.36 vs 1.70 Mcal/kg DM respectively for PR and CS diets). In order to meet the high demand of nutrients needed to assure high milk production, in addition to fodder a lot of concentrates are also used in dairy cows’ TMR. A survey analysis conducted in commercial farms was performed to evaluate the GWP of different lactating cow TMR and to identify the best dietary strategies to increase the FE and to reduce the enteric CH4 emission. A total of 171 dairy herds were selected: data about DMI, lactating cows TMR composition, milk production and composition were provided by farmers. Diet GWP (kg CO2 eq) was calculated as sum of GWP of each ingredient considering inputs needed at field level, feed processing and transport. For SBM, land use change was included in the assessment. Enteric CH4 production (g/d) was estimated using the equation of Hristov et al. (2013) in order to calculate CH4 emission for kg of FPCM. The dataset was analysed by GLM and logistic analysis using SAS 9.4. The results of frequency distribution showed that there was a wide variation among farms for the GWP of TMR: approximately 25% of the surveyed farms showed a diet GWP of 15 kg CO2 eq, 20% of 13 kg CO2 eq and 16.7% of 17 kg CO2 eq. The variation among farms is due to the feed used. Among feed, SBM had the highest correlation with the GWP of the TMR with the following equation: TMR GWP (kg CO2 eq) = 2.49*kg SBM + 6.9 (r2=0.547). Moreover, an inclusion of SBM >15% of diet DM did not result in higher milk production with respect to a lower inclusion (≤15%). Average daily milk production of cows was 29.8 (SD 4.83) kg with a fat and protein content (%) of 3.86 (SD 0.22) and 3.40 (SD 0.14), respectively. The average value of DMI (kg/d) of lactating cows was 22.3 (SD 2.23). The logistic analysis demonstrated that a level of corn silage ≤ 30% on diet DM was associated with higher FE. Almost 50% percent of the farms had an average value of 15.0 g CH4/kg FPCM and about 30% a value of 12.5 g CH4/kg FPCM. The results demonstrated that a lower enteric CH4 production was related to inclusion (% on diet DM) of less than 12% of alfalfa hay and more than 30% of corn silage. Diets with more than 34% of NDF determined higher CH4 production (≥14.0 g/kg FPCM) compared with diets with lower NDF content. On the contrary, a lower enteric CH4 production (<14.0 g/kg FPCM) was related to diets characterized by more than 1.61 NEl (Mcal/kg) and more than 4% of ether extract. The variability in the GWP of TMR shows a significant potential to reduce both the GWP of the diet through a correct choice and inclusion level in the ration of the ingredients (mainly SBM) and the possibility to decrease CH4 enteric emission associated to milk production. Looking forward, in order to evaluate the opportunity of alternative protein sources in the cow diet, to reduce SBM, waste production, and competition between animals and human for crops, a study on the effects of different by-products for Hermetia illucens rearing on the chemical composition of larvae and their environmental impact was conducted, even if, according to the European legislation, today the use of insects as feed source is not possible in ruminants. Regarding climate change, okara and brewer’s grains were the most promising substrates: 0.197 and 0.228 kg CO2 eq/kg of larvae fresh weight, respectively. Results from these studies show the importance of adopting a holistic approach for the assessment of GHG emission from milk production. Therefore, any strategy aimed at mitigating CH4 emission of dairy cows must also take into account the possible effect on the other GHGs, as well as the effect on C sequestration. Based on the studies, it could also be worth evaluating novel feed as a new and useful solution for mitigation of GHG emission related to milk production. The thesis highlights essential differences among forage systems and among feed ingredients of cow ration, confirming that there is room for improvement in sustainability of milk production. These issues should be taken into consideration by farmers, technicians and policy makers, considering that sustainability of livestock production will be one of the priorities for humankind in next future
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
Fodder systems and environmental impact of cow milk production in Italy
No full textTake home message. Fodder systems choices can change the environmental impact of milk production in dairy cow farms. Fodder systems based on permanent and multiannual crops, as grassland and lucerne, can be helpful in mitigating environmental load of milk production compared to systems based on arable crops, as maize or winter cereals.
Introduction. Animal feeding, and in particular protein feeding, is a critical point in the livestock sector. The choice of crop system for home-grown fodder production can be crucial in the environmental prospective, it can affect feed self-sufficiency, amount and type of purchased feeds, efficiency of feed conversion, stocking rate but also the use of fertilizers and fuel consumption in field operations. The aim of the study was to evaluate, through a Life Cycle Assessment approach, the environmental impact of milk production in three groups of farms, characterized by different fodder systems.
Material and methods. Inventory data about milk production, herd composition, feeding rations, housing system, manure management and crop production from 17 dairy farms of the Po plain were collected. Farms were divided in three groups on the basis of percentage of land with permanent and multiannual fodder crops (grassland or lucerne) on the total fodder agricultural area (Multiannual). Grazing was not adopted by any farm. Feeding ration composition were calculated using CPM-Dairy Ration software. Gas emissions were estimated according to IPCC (2006) and EEA (2009). Environmental impact categories, expressed per kg of Fat and Protein Corrected Milk (FPCM), were estimated with the methods recommended by ILCD Handbook (IES, 2012) and using the SIMAPRO software (Prè Consultants 2014).
Results & Discussion. Farms with less than 20% of Multiannual were characterized by the smallest agricultural area, the largest herd size and the lowest dairy efficiency (59 ha, 176 lactating cows and 1.11 kg milk/kg dry matter intake on average, respectively). The most productive herds were in the intermediate group (20-50% of Multiannual) with 27.4 kg FPCM/cow per year, while the last group of farms, characterized by >50% of Multiannual, showed the lowest stocking density (3.39 LU/ha) and the lowest use of nitrogen from synthetic fertilizer (22 kg/ha per year).
The results of impact categories showed the lowest values in the group of farms with >50% Multiannual. In particular, climate change per kg FPCM decreased as percentage of Multiannual increased; at the same time also feed self-sufficiency, both as dry matter and as crude protein, tended to increase, probably because the farms with >50% Multiannual were able to reduce the quota of high impact purchased feeds (particularly soybean meal, one of the most impactful feed on climate change) without compromising milk production. The same farms used the lowest amount of nitrogen fertilizer (both synthetic and organic), thanks to the low presence of annual crops, with an important restrain of acidification.
Conclusion. Fodder systems characterized by extensive use of permanent and multiannual crops, as grassland and lucerne, can reduce the environmental impact of milk production in comparison to systems based on arable land due to the high amount of feed self-production, both energy and protein feeds, and the reduced use of nitrogen fertilizers
Management practices and milk quality in dairy goat farms in Northern Italy
No full textA large-scale survey was conducted on 173 dairy goat farms in Northern Italy to provide an updated view on farm management practices and to investigate relations among management factors, herd traits and milk yield and quality with particular focus on milk somatic cell count (SCC) and milk fat/protein reversion syndrome. Monthly individual milk analyses (fat, protein and lactose percentages, SCC) and bulk tank milk analyses (fat, protein and lactose percentages, standard plate count (SPC), urea and casein) from 91 farms out of the 173 farms were collected for a year. Farming systems showed wide variability and were characterised by the coexistence of intensive farms adopting advanced technologies and extensive traditional ones. Average milk production was 1.25 kg/milking with high variability, significantly influenced by days in milk, month of kidding, herd size and parity. Out-of-season breeding was predicted to cause a slight reduction of milk production. The reversion syndrome between milk fat and protein contents affected more than half of samples. It worsened after 100 d of lactation and occurred earlier during lactation when kidding was in the late season (April–June) compared to kidding in the first months of the year. The defect was associated with high SCC in milk. The yearly average milk SCC was 5.8 log10 cells/mL; it was higher at the end of lactation and in goats kidding in the late season. A negative relationship between SCC and milk yield was found with an estimated loss of 0.23 kg per milking for each additional point of log10 SCC
Air Quality, Management Practices and Calf Health in Italian Dairy Cattle Farms
No full textAmong factors that can affect calf health, microbial quality of the pen air is poorly studied. In 25 Italian dairy farms, data concerning air quality in the calf pens, hygiene of pens and equipment, microclimatic conditions, calf health and management were collected during the winter season (January-March 2020 and December-March 2021). The average air Standard Plate Count (SPC) of 85 pens was 4.51 (SD = 0.52) log10 cfu/m3 whereas the average air ammonia concentration was 0.66 (SD = 0.53) ppm. Positive correlations were found between average Temperature Humidity Index (THI) in the pen and air SPC, night maximum THI and air SPC and between SPC and yeast, mould and ammonia concentration in the pen air. The concentrations of E. coli, Enterobacteriaceae and yeasts in the pen air were higher and calf cough increased as the renewal interval of bedding material became longer. High bedding dry matter and low THI were associated with low air SPC, good calf health scores and low mortality. Maintaining low bedding humidity and controlling microclimatic conditions can contribute to enhancing air microbiological quality in the pen and reduce calf diseases and mortality
Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
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Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
by Giulia Di Iorio,Laura Paglia *ORCID,Giulia PedrizzettiORCID,Virgilio GenovaORCID,Francesco MarraORCID,Cecilia BartuliORCID andGiovanni PulciORCID
INSTM Reference Laboratory for Materials and Surface Engineering, Sapienza University of Rome, Eudossiana 18, 00184 Rome, Italy
*
Author to whom correspondence should be addressed.
Coatings 2023, 13(9), 1602; https://doi.org/10.3390/coatings13091602
Original submission received: 10 August 2023 / Revised: 31 August 2023 / Accepted: 11 September 2023 / Published: 13 September 2023
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Abstract
SiC/SiC ceramic matrix composites (SiCf/SiC CMCs) are regarded as the new materials for the hot-section components of aircraft gas turbine engines, since they have one-third of the density of metallic superalloys, a higher temperature capability, good mechanical strength, and excellent thermal shock resistance. However, high-temperature water-vapor-rich combustion gases can induce severe surface recession phenomena in SiC/SiC leading to component failure. For this reason, it is necessary to design protective coatings, i.e., environmental barrier coatings (EBCs), able to protect the SiC/SiC surface in combustion environments. In the present work, ytterbium monosilicate (Yb2SiO5), stable when exposed to water vapor at high temperatures, and ytterbium disilicate (Yb2Si2O7), characterized by a thermal expansion coefficient closer to that of the substrate, were selected for a multilayer EBC system. EBCs were processed using the atmospheric plasma spray (APS) technique. A set of deposition parameters were tested, varying the power of the torch, and the composition and microstructure of the deposited coatings were studied in terms of porosity, crack density, and post-deposition phase retention by performing SEM, EDS, and XRD analysis. The results allow for the definition of the influence of deposition parameters on the final properties of multilayer EBC coatings
Correction to: Safety and Psychological Outcomes of Tandem t:Slim X2 Insulin Pump with Control-IQ Technology in Children, Adolescents, and Young Adults with Type 1 Diabetes: A Systematic Review
No full textThe second author name was incorrectly published as Giula Maria Smylie. The correct name is Giulia Marie Smylie. The original article has been corrected
How much is the environmental benefit of using precision livestock farming in Italian dairy farms?
No full textScrivere senza anestesia. La chiarezza di Giulia Niccolai
No full textIl saggio colloca storicamente la narratrice e poetessa Giulia Niccolai nel canone del Novecento letterario italiano discutendone poetica e cifre stilistiche. L'ampia analisi proposta tocca tutte le opere dell'autrice evidenziandone i legami intertestuali, anche tra poesia e narrativa, e i progressivi sviluppi in un arco cronologico esteso, tra anni Sessanta e primi anni Duemila. Lo studio coglie anche l'importanza dei riferimenti alle arti visive, in particolare alla fotografia, che Giulia Niccolai ha praticato in prima persona negli anni della Neoavanguardia, e alla pittura americana.The essay places the narrator and poet Giulia Niccolai in the canonical twentieth century Italian literary discussing her poetics and stylistic figures. The wide analysis proposed touches all the works of the author highlighting the intertextual links, also between poetry and narrative, and the progressive developments in an extended chronological period, between the Sixties and early Twenties. The study also captures the importance of references to the visual arts, especially photography, which Giulia Niccolai has practiced in the years of the Neo-avant-garde, and to American painting
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