Performance, Meat Quality and Meat Metabolomics Outcomes: Efficacy of 3-Nitrooxypropanol in Feedlot Beef Cattle Diets.

30 Nellore animals with an average weight of 407.25 ± 2.04 kg, were distributed in a completely randomized design across the following treatments: 1-Control (without inclusion of 3-NOP); 2-BV75 (inclusion of 3-NOP at 75 mg/kg DM); 3-BV100 (inclusion of 3-NOP at 100 mg/kg DM). No significant effects were observed between treatments on ingestive behavior. However, the notable effect on the BWfinal and ADG of animals supplemented with 3-NOP compared to the control group was measurable. Cattle beef receiving 3-NOP exhibited reduced methane emissions (p < 0.0001) for all variables analyzed, resulting in an average decrease of 38.2% in methane emissions compared to the control, along with increased hydrogen emissions (g/day) (p < 0.0001). While supplementation with BV100 demonstrated lower methane emission, the performance was lower than BV75 in DMI, BWfinal, ADG, and ADG carcasses. Partial separation of metabolomics observed between groups indicated changes in meat metabolism when comparing the control group with the 3-NOP group, identifying metabolites with a variable importance projection (VIP) score > 1. In conclusion, supplementation with 3-NOP effectively reduced methane emissions and did not negatively influence animal performance.

Deciphering the role of Moringa oleifera seeds and probiotic bacteria on mitigation of biogas production from ruminants.

Maintaining cleaner and more sustainable ecosystems by mitigating greenhouse gas (GHG) emissions from livestock through dietary manipulation is in demand. This study was aimed to assess the effect of Moringa oleifera seeds and probiotics (Pediococcus acidilactici BX-B122 and Bacillus coagulans BX-B118) as feed supplements on GHG production and fermentation profile from steers and sheep. The treatments included diets containing 0, 6, 12, and 18% of M. oleifera seeds meal and a mixture of probiotic bacteria (0.2 ml/g of diet). Total biogas production, CH4, CO, and H2S emission from animals (up to 48 h), rumen fermentation profile, and CH4 conversion efficiency were recorded using standard protocols. Results showed interaction among M. oleifera seeds and probiotics on asymptotic biogas production and total biogas production up to 48 h (P < 0.05). The rate of CH4 emission in steers was reduced from 0.1694 to 0.0447 ml/h using 6 and 18% of M. oleifera seeds (P < 0.05). Asymptotic CO and the rate of CO production were increased (P < 0.05) by supplementing different doses of M. oleifera seeds and probiotics. Adding 12% of M. oleifera seeds and probiotics reduced H2S production from 0.0675 to 0.0112 ml H2S/g DM (at 48 h of fermentation) in steers. In sheep, the additives mitigated H2S production from 0.0364 to 0.0029 ml H2S/g DM (at 48 h of fermentation), however there were not interaction (P = 0.7744). In addition, M. oleifera seeds and probiotics reduced the pH level and dry matter degradability (DMD) in steers and sheep (P < 0.0001) showing a positive impact on CH4:ME and CH4:OM (in steers) and CH4:SCFA (in sheep), while the interaction was not significant (P > 0.05) for CH4:SCFA (in steers) and CH4:ME and CH4:OM (in sheep). In conclusion, the interaction of M. oleifera seeds and probiotics in the feeding diet reduced GHG emissions and affected the fermentation profile of steers and sheep.

Essential Oils in Nellore Beef Cattle: In Vivo Impact on Rumen Emissions.

Essential oils (EOs), as rumen additives, decreased CH4 emissions in in vitro trials but results from in vivo studies are still limited. We investigated the effects of Origanum vulgare (OEO) and Thymus vulgaris (TEO) EOs on in vivo methane emissions from Nellore beef cattle. Six adult rumen-cannulated Nellore cattle were used in a double 3 × 3 Latin square design. Treatments consisted of three diets containing either 3 mL OEO per kg of concentrate, 3 mL TEO/kg of concentrate, or no EO addition. The experimental period consisted of three 21 d feeding periods and methane production was measured using the sulfur hexafluoride (SF6) technique from Day 16 to Day 21 of each feeding period. Intake, total apparent digestibility (dry matter as well as neutral and acid detergent fiber), and rumen parameters (pH, ammoniacal nitrogen concentration, and short-chain fatty acids) were also evaluated. The EOs did not decrease CH4 emissions and had no effect on rumen parameters.

Greenhouse gases capture applying impregnated silica with ionic liquids, deep eutectic solvents, and natural deep eutectic solvents.

The development of technologies to capture greenhouse gases (GHGs) like carbon dioxide (CO2) and nitrous oxide (N2O) is vital for climate change mitigation. Ionic liquids (ILs), deep eutectic solvents (DES), and natural deep eutectic solvents (NADES) are promising absorbents to abate GHGs emissions. However, their high viscosity limits the gas-liquid contact, as consequence of the mass transfer. To overcome this, their impregnation onto porous silica gel has been carried out, increasing the gas-liquid contact area. The present study analyzes the effect of size particle of silica gel impregnated with ILs, DES, and NADES over the CO2 and N2O capture at atmospheric conditions. The degree of impregnation of silica particles was determined by thermogravimetric analysis (TGA). The identification of functional groups present on the surface of silica, ILs, DES, and NADES was performed using Fourier-transform infrared spectroscopy (FTIR), and their crystalline structure was determined by X-ray diffraction (XRD). The partition coefficient of CO2 and N2O between gas and ILs, DES, and NADES was determined by a static headspace method. Results show that the degree of solvent impregnation on silica gel ranged from 36.8 to 43.0% w/w, the partition coefficient of CO2 in the impregnated silica varied from 0.005 to 0.067, and for N2O, from 0.005 to 0.032. This suggests that impregnated particles have a greater affinity for N2O compared to CO2. Using impregnated particles requires only 40% of the bulk solvent to achieve a similar GHG capture capacity compared to using bulk solvents.

Composition of the rumen microbiome and its association with methane yield in dairy cattle raised in tropical conditions.

BACKGROUND: Methane (CH4) emissions from rumen fermentation are a significant contributor to global warming. Cattle with high CH4 emissions tend to exhibit lower efficiency in milk and meat production, as CH4 production represents a loss of the gross energy ingested by the animal. The objective of this study was to investigate the taxonomic and functional composition of the rumen microbiome associated with methane yield phenotype in dairy cattle raised in tropical areas. METHODS AND RESULTS: Twenty-two Girolando (F1 Holstein x Gyr) heifers were classified based on their methane yield (g CH4 / kg dry matter intake (DMI)) as High CH4 yield and Low CH4 yield. Rumen contents were collected and analyzed using amplicon sequencing targeting the 16 and 18S rRNA genes. The diversity indexes showed no differences for the rumen microbiota associated with the high and low methane yield groups. However, the sparse partial least squares discriminant analysis (sPLS-DA) revealed different taxonomic profiles of prokaryotes related to High and Low CH4, but no difference was found for protozoa. The predicted functional profile of both prokaryotes and protozoa differed between High- and Low CH4 groups. CONCLUSIONS: Our results suggest differences in rumen microbial composition between CH4 yield groups, with specific microorganisms being strongly associated with the Low (e.g. Veillonellaceae_UCG - 001) and High (e.g., Entodinium) CH4 groups. Additionally, specific microbial functions were found to be differentially more abundant in the Low CH4 group, such as K19341, as opposed to the High CH4 group, where K05352 was more prevalent. This study reinforces that identifying the key functional niches within the rumen is vital to understanding the ecological interplay that drives methane production.

Estimación de emisiones de gases de efecto invernadero en la dieta de mujeres adolescentes en áreas rurales de oriente de Guatemala / Estimation of greenhouse of gas emissions in the diet of adolescent women in rural areas of eastern Guatemala

Introducción. La producción de alimentos es una de las principales causas de Emisiones de Gases de Efecto Invernadero (GEI). Estimar las emisiones GEI de la dieta es el punto de partida para definir dietas saludables y sostenibles con el ambiente. Objetivo. Estimar el total GEI de la dieta de mujeres adolescentes del oriente de Guatemala, así como la contribución de grupos de alimentos a este valor. Materiales y métodos. En el contexto de un estudio de agricultura y nutrición en el oriente de Guatemala, se realizó un análisis secundario de los datos dietéticos (Recordatorio de 24 horas) de 2082 mujeres adolescentes. Los alimentos reportados fueron enlazados con la base de datos SHARP, que contiene estimaciones de GEI para 944 alimentos. La variable de enlace fue un código único armonizado con el sistema de clasificación FoodEx2. Resultados. La dieta es poco diversa, principalmente a base de grupos de alimentos de origen vegetal, con poca presencia de alimentos de origen animal. El GEI de la dieta fue de 2,3 Kg CO2 eq/ per cápita/día, con la mayor contribución de comidas preparadas (26,7%) y panes, tortillas y similares (12,8%). Conclusiones. La dieta de las mujeres adolescentes de áreas rurales de Guatemala tiene un GEI inferior al reportado en otros países de la región para estratos socioeconómicos con mayor consumo de alimentos de origen animal. Este estudio es el punto de partida para sistematizar la metodología para continuar con las estimaciones de GEI en Guatemala(AU)

Introduction. Food production is one of the main causes of Greenhouse Gas Emissions (GHGE). Estimating GHG emissions from the diet is the starting point for defining healthy and environmentally sustainable diets. Objective. Estimate the total GHGE in the diet of adolescent women from eastern Guatemala, as well as the contribution of food groups to this value. Materials and methods. In the context of an agriculture and nutrition study in eastern Guatemala, a secondary analysis of dietary data (24-hour recall) of 2082 adolescent women was performed. The reported foods were linked to the SHARP database, which contains GHGE estimates for 944 foods. The linking variable was a unique code harmonized with the FoodEx2 classification system. Results. The diet is not diverse, mainly based on food groups of plant origin, with little presence of foods of animal origin. The GHG of the diet was 2.3 Kg CO2 eq/per capita/day, with the greatest contribution from prepared foods (26.7%) and breads, tortillas and similar products (12.8%). Conclusions. The diet of adolescent women in rural areas of Guatemala has a lower GHG than that reported in other countries in the region for socioeconomic strata with greater consumption of foods of animal origin. This study is the starting point to systematize the methodology to continue with GHG estimates in Guatemala(AU)

Nitrous oxide and methane emissions from a Ferralsol as affected by loblolly pine cultivation time in subtropical Brazil.

We hypothesized that the age of loblolly pine stands influences soil methane (CH4) and nitrous oxide (N2O) emissions. This is a relevant topic to be studied in subtropical Brazil, where the pine plantation area is increasing considerably. We evaluated N2O and CH4 emissions for two years in a Ferralsol under loblolly pine (Pinus taeda L.) stands of 1, 9 and 18 year-olds and a native forest (NF). We calculated the net CO2eq emission by considering the N2O and CH4 emissions from soil and the carbon (C) accumulation as litter in the forest floor. The soil N2O emission reduced gradually over the loblolly pine cultivation years, whereas CH4 uptake rates showed no clear pattern. Soil N2O emission showed a positive relationship with soil temperature in NF, and with soil ammonium and nitrate intensities in the pine stands. Soil CH4 uptake was inversely related to water-filled pore space in the pine stands, but this relationship was not observed in NF. The soil CH4 uptake rate was 4.6 times higher (p < 0.10) in NF than the average uptake in loblolly pine stands. On the other hand, soil N2O emissions in 9 and 18-year-old stands were similar (p > 0.10) to those in NF (1.3 kg N ha-1 yr-1). Our results suggest that cultivation with loblolly pine for 18 years can reduce soil N2O emission, and the uptake of CH4 in this system offsets 17 % of N2O emissions. Furthermore, the C accumulation as litter in the forest floor of the mature pine stands (9- and 18-year-old) generated a net emission of -1.6 Mg CO2eq ha-1 yr-1, showing to be an expressive offsetting mechanism. Therefore, we conclude that aged loblolly forests can reach N2O emissions levels comparable to those of NF, and the C sequestration in these forests floor can significantly contribute to offset N2O emissions and act as sink for net atmospheric CO2eq.

Feeding 3-nitrooxypropanol reduces methane emissions by feedlot cattle on tropical conditions.

Our objective was to evaluate the effects of feeding 3-nitrooxypropanol (3-NOP; Bovaer, DSM Nutritional Products) at two levels on methane emissions, nitrogen balance, and performance by feedlot cattle. In experiment 1, a total of 138 Nellore bulls (initial body weight, 360 ± 37.3 kg) were housed in pens (27 pens with either 4 or 5 bulls per pen) and fed a high-concentrate diet for 96 d, containing 1) no addition of 3-NOP (control), 2) inclusion of 3-NOP at 100 mg/kg dry matter (DM), and 3) inclusion of 3-NOP at 150 mg/kg DM. No adverse effects of 3-NOP were observed on DM intake (DMI), animal performance, and gain:feed (P > 0.05). In addition, there was no effect (P > 0.05) of 3-NOP on carcass characteristics (subcutaneous fat thickness and rib eye area). In experiment 2, 24 bulls (initial BW, 366 ± 39.6 kg) housed in 12 pens (2 bulls/pen) from experiment 1 were used for CH4 measurements and nitrogen balance. Irrespective of the level, 3-NOP consistently decreased (P < 0.001) animals' CH4 emissions (g/d; ~49.3%), CH4 yield (CH4/DMI; ~40.7%) and CH4 intensity (CH4/average daily gain; ~38.6%). Moreover, 3-NOP significantly reduced the gross energy intake lost as CH4 by 42.5% (P < 0.001). The N retention: N intake ratio was not affected by 3-NOP (P = 0.19). We conclude that feeding 3-NOP is an effective strategy to reduce methane emissions, with no impairment on feedlot cattle performance.

During fiber digestion in the rumen, enteric methane is produced. Methane is a potent greenhouse gas. Recently several studies have focused on developing synthetic compounds and their utilization as specific inhibitors of methanogenesis. 3-Nitrooxypropanol is a structural compound that can help to mitigate CH4 emissions. The objective of this study was to evaluate the effects of feeding 3-nitrooxypropanol (3-NOP; Bovaer, DSM Nutritional Products) at two levels on methane emissions, nitrogen balance, and performance by feedlot cattle. No effect of 3-NOP on animal performance and N balance was found. However, regarding CH4 production 3-NOP consistently decreased (P < 0.001) animals' CH4 emissions (g/d; ~49.3%), methane yield (CH4/dry matter intake; ~40.7%), and CH4 intensity (CH4/average daily gain; ~38.6%). This study provides information on the potential role of 3-NOP on reducing CH4 emissions from feedlot cattle without reducing animal performance.

Assessment of heat production and methane emission using infrared thermography in lactating Holstein and Gyrolando-F1 (½ Holstein ½ Gyr) crossbreed cows.

Infrared thermography (IRT) is a non-invasive and efficient tool to detect changes in the animal's body surface temperature, which is directly associated with the animal's energy loss. Methane emission represents a significant energy loss, particularly in ruminants, as well as heat production. Therefore, the aim of this study was to correlate skin temperature measured using IRT with heat production (HP) and methane emission in lactating Holstein and crossbred ½ Holstein x ½ Gyr (Gyrolando-F1) cows. Six Gyrolando-F1 and four Holstein cows, all primiparous, at mid lactation were used to evaluate daily HP and methane emission using indirect calorimetry in respiratory chambers. Thermographic images were taken at anus, vulva, ribs (on the right side), left flank, right flank, right front foot, upper lip, masseter and eye; IRT was performed every hour during 8 h after the morning feeding. Cows received the same diet ad libitum. Daily methane emission was positively correlated with IRT taken at the right front foot 1 h after feeding in Gyrolando-F1 cows (r = 0.85, P < 0.05) and with IRT taken at the eye 5 h after feeding in Holstein cows (r = 0.88, P < 0.05). HP was positively correlated with IRT taken at the eye 6 h after feeding in Gyrolando-F1 cows (r = 0.85, P < 0.05) and with IRT taken at the eye 5 h after feeding in Holstein cows (r = 0.90, P < 0.05). Infrared thermography was positively correlated with HP and methane emission in both Holstein and Gyrolando-F1 lactating cows, although the anatomical points and times of image acquisition yielding the greatest correlation coefficients varies among breeds.

Substitutional Coinage Metals as Promising Defects for Adsorption and Detection of Gases on MoS2 Monolayers: A Computational Approach.

Defective molybdenum disulfide (MoS2) monolayers (MLs) modified with coinage metal atoms (Cu, Ag and Au) embedded in sulfur vacancies are studied at a dispersion-corrected density functional level. Atmospheric constituents (H2, O2 and N2) and air pollutants (CO and NO), known as secondary greenhouse gases, are adsorbed on up to two atoms embedded into sulfur vacancies in MoS2 MLs. The adsorption energies suggest that the NO (1.44 eV) and CO (1.24 eV) are chemisorbed more strongly than O2 (1.07 eV) and N2 (0.66 eV) on the ML with a cooper atom substituting for a sulfur atom. Therefore, the adsorption of N2 and O2 does not compete with NO or CO adsorption. Besides, NO adsorbed on embedded Cu creates a new level in the band gap. In addition, it was found that the CO molecule could directly react with the pre-adsorbed O2 molecule on a Cu atom, forming the complex OOCO, via the Eley-Rideal reaction mechanism. The adsorption energies of CO, NO and O2 on Au2S2, Cu2S2 and Ag2S2 embedded into two sulfur vacancies were competitive. Charge transference occurs from the defective MoS2 ML to the adsorbed molecules, oxidizing the later ones (NO, CO and O2) since they act as acceptors. The total and projected density of states reveal that a MoS2 ML modified with copper, gold and silver dimers could be used to design electronic or magnetic devices for sensing applications in the adsorption of NO, CO and O2 molecules. Moreover, NO and O2 molecules adsorbed on MoS2-Au2s2 and MoS2-Cu2s2 introduce a transition from metallic to half-metallic behavior for applications in spintronics. These modified monolayers are expected to exhibit chemiresistive behavior, meaning their electrical resistance changes in response to the presence of NO molecules. This property makes them suitable for detecting and measuring NO concentrations. Also, modified materials with half-metal behavior could be beneficial for spintronic devices, particularly those that require spin-polarized currents.

Influence of Azadirachta indica and Cnidoscolus angustidens aqueous extract on cattle ruminal gas production and degradability in vitro.

Introduction: Mitigation of ruminant greenhouse gas (GHG) emissions is crucial for more appropriate livestock production. Thus, there is a need of further research evaluating feed supplementation strategies to mitigate enteric GHG emissions and other gases produced within the rumen. Methods: This study was conducted as a completely randomized experimental design to determine the effectiveness of liquid extracts from A. indica (AZI), C. angustidens (CNA), or their combination (Mix. 1:1) at dosages of 0, 36, 72, and 108 mg of liquid extract/g DM substrate incubated in reducing GHG production in vitro, particularly methane (CH4), from the diet of steers during anaerobic incubation in rumen fluid. Total gas production, CH4, CO, H2S, and fermentative characteristics were all measured in vitro. Results: Treatment AZI at a dose of 108 mg of liquid extract/g DM substrate produced the highest (P < 0.05) gas volume at 6 h, whereas CNA at a dose of 72 mg of liquid extract/ g DM substrate produced the least (P < 0.05) at 6 and 24 h, and Mix. at a dose of 72 mg of liquid extract/g DM substrate produced the least (P < 0.05) at 48 h. In addition, CH4 levels at 6 and 24 h of incubation (36 mg/g DM substrate) were highest (P < 0.05) for CNA, and lowest (P < 0.05) for AZI, whereas this variable was lowest (P < 0.05) at 72 mg of liquid extract for CNA at 24 and 48 h. At 6 and 24 h, CO volume was highest (P < 0.05) for AZI at 108 mg of liquid extract and lowest (P < 0.05) for Mix. at 72 mg of liquid extract. Treatment Mix. had a high (P < 0.05) concentration of short chain fatty acids at 72 mg of liquid extract/g DM of substrate. Discussion: In general, herbaceous perennial plants, such as AZI and CNA, could be considered suitable for mitigating enteric GHG emissions from animals. Specifically, the treatment Mix. achieved a greater sustainable reduction of 67.6% in CH4 and 47.5% in H2S production when compared to either AZI. This reduction in CH4 might suggest the potential of the combination of both plant extracts for mitigating the production of GHG from ruminants.

Calidad nutricional e impacto en medio ambiente por los insumos de un comedor universitario en Uruguay / Nutritional quality and environmental impact by the inputs of a university canteen in Uruguay

El espacio de comedores son una forma de garantizar el acceso a alimentos seguros, saludables y medio ambientalmente responsables para los estudiantes universitarios. Objetivo. Este estudio tuvo como objetivo caracterizar los estándares del menú, a partir de la evaluación de la calidad nutricional y del impacto en el medio ambiente por los insumos utilizados para su elaboración por un Comedor Universitario (CU) en Uruguay. Materiales y métodos. Se trató de un estudio de caso retrospectivo, relativo al año 2021. Las variables evaluadas fueron a) cantidad total de alimento comprado en kilogramos (kg); b) cantidad en kilocalorías (kcal) e impactos ambientales por: c) generación de residuos; d) huella hídrica (HH); y e) gases de efecto invernadero (GEI). También se realizaron cálculos para evaluar la ecoeficiencia (EE). Resultados. El CU sirvió 33.740 comidas en 2021, de las cuales el 87,1% fueron almuerzos. De los 78 tipos de alimentos comprados, 41 de ellos representaron el 93,17% del total en kilogramos. En la calidad nutricional, menos del 10% se clasificaron como alimentos procesados o ultraprocesados. En la evaluación de aspectos nutricionales e impactos ambientales, los alimentos de origen animal representaron el 26,52% del total en kg y el 69,78% de los HH. Un alimento de origen vegetal tuvo el mayor impacto de GEI debido a su origen. En cuanto a la EE, la valoración general mostró un resultado de 0,0626 para los alimentos de origen animal y 0,3838 para los de origen vegetal. Conclusiones. Corresponde a los servicios de alimentación para colectividades considerar, en la planificación del menú, además de la calidad nutricional y sanitaria de la oferta alimentaria, los impactos ambientales que estas genera(AU)

The canteens are a way to guarantee access to safe, healthy and environmentally responsible food for university students. Objective. The purpose of this research was to characterize the menu standards, based on the evaluation of the nutritional quality and the environmental impact of the inputs used for its preparation by a university canteen in Uruguay. Materials and methods. This was a retrospective case study, relating to the year 2021. The variables evaluated were a) total amount of food purchased in kilograms (kg); b) quantity in kilocalories (kcal) and environmental impacts due to: c) waste generation; d) water footprint (WF); and e) greenhouse gases (GHG). Calculations were also performed to assess eco-efficiency (EE). Results. The university canteen served 33,740 meals in 2021, of which 87.1% were lunches. Of the 78 types of food purchased, 41 of them represented 93.17% of the total in kilograms. In nutritional quality, less than 10% are classified as processed or ultra-processed foods. In the evaluation of nutritional aspects and environmental impacts, foods of animal origin represented 26.52% of the total in kg and 69.78% of WF. A vegetal based food had the highest GHG impact due to its origin. Regarding the EE calculations, the general assessment showed a result of 0.626 for foods of animal origin and 0.3838 for those of vegetable origin. Conclusions. It corresponds to the food services for communities to consider, in the planning of the menu, in addition to the nutritional and sanitary quality of the food offer, the environmental impacts that it generates(AU)

Juicios de daños y aporte de los tribunales chilenos ante los desafíos ético-ambientales que impone el cambio climático / Litigation for damages and contribution of the Chilean courts to the ethical-environmental challenges posed by climate change / Julgamento de danos e contribuições dos tribunais chilenos diante dos desafios ético-ambientais trazidos pela mudança climática

Este artículo muestra que la experiencia acumulada por la Corte Suprema chilena en juicios sobre responsabilidad civil y ambiental, debiera permitirle abordar los problemas ético-ambientales y jurídicos que el calentamiento global implica, sea previniendo daños mediante la imposición a los principales emisores de gases de efecto invernadero, incluido el Estado, del deber de reducir acelerada y significativamente las emisiones, sea exigiendo y haciendo cumplir la obligación de adaptación al cambio climático mediante la atribución de responsabilidad extracontractual o ambiental.

This article shows that the experience accrued by the Chilean Supreme Court in lawsuits on tort and environmental liability, should allow it to address the ethical-environmental and legal issues that global warming implies, either by preventing harm through the imposition on the major emitters of greenhouse gases, including the State, of the duty to reduce emissions rapidly and significantly, or by demanding and enforcing the obligation to adapt to climate change through the attribution of tort liability or environmental liability.

Esse artigo mostra que a experiência acumulada pela Corte Suprema chilena em julgamentos sobre responsabilidade civil e ambiental, deveria permitir-lhe abordar os problemas ético-ambientais e jurídicos que o aquecimento global implica, seja prevenindo danos mediante a imposição aos principais emissores de gases de efeito estufa, incluindo o Estado, do dever de reduzir acelerada e significativamente as emissões, seja exigindo e fazendo cumprir a obrigação de adaptação à mudança climática mediante a atribuição de responsabilidade extracontratual ou ambiental.

Methane emission, intake, digestibility, performance and blood metabolites in sheep supplemented with cupuassu and tucuma cake in the eastern Amazon.

The use of co-products as a feed supplement for ruminants makes livestock sustainable and optimizes the use of available areas and animal performance. Furthermore, when cakes are used, the residual fat composition can influence ruminal metabolism and methane (CH4) production. This study aimed to assess the effects of a diet containing cupuassu (CUP; Theobroma grandiflorum) and tucuma (TUC; Astrocaryum vulgare Mart.) cakes on intake, digestibility, serum metabolites, performance, and CH4 emissions in confined sheep in the Amazon. Approximately 28 animals, Dorper-Santa Inês, castrated, with an average initial live weight (ILW) of 35 ± 2.3 kg, were distributed in metabolic cages, in a completely randomized design, with four treatments and seven replications: (1) Control (C40), without the addition of Amazonian cake and with 40 g of ether extract (EE)/kg of dietary dry matter (DM); (2) CUP, the inclusion of the CUP cake and 70 g of EE/kg; (3) TUC, the inclusion of the TUC cake and 70 g of EE/kg; and (4) Control (C80), without the addition of Amazonian cake and with 80 g of EE/kg of dietary DM, with roughage to concentrate ratio of 40:60. The use of the TUC cake as a feed supplement reduced the intake of DM, crude protein (CP), and EE compared to the inclusion of the CUP cake (p < 0.05); however, it increased the intake of neutral detergent fiber (NDF) by 32% (p < 0.01). The highest averages of DM (732 g/kg) and CP (743 g/kg) digestibility were presented in C40, while the highest digestibility of NDF was presented in TUC (590 g/kg). Albumin levels stayed above and protein levels were below the reference values, and the C40 diet also obtained below results for cholesterol, triglycerides and High Density Lipoprotein (HDL) (P < 0.05). Sheep fed CUP (91 g) and TUC (45 g) had lower daily weight gains (DWGs) than those fed with diets without the inclusion of cakes (C40 = 119 g; C80 = 148 g), and feed efficiency (FE) was also lower in CUP (84) and TUC (60) diets than in C40 (119) and C80 (137) diets. CH4 emissions were lower in animals fed TUC (26 L/day) and higher in C40 (35 L/day); however, TUC resulted in higher CH4 emissions in grams/body live weight (BW) gain/day (353 g/BW/day) vs. 183 g/BW/day (C40), 157 g/BW/day (C80), and 221 g/BW/day (CUP). The supplementation with cakes did not improve intake, digestibility and performance, did not compromise blood metabolites and did not reduce the enteric CH4 emission in confined sheep in the Amazon; however, the use of CUP cake showed similar results to the control treatments and did not increase CH4 emissions, as occurred with the inclusion of TUC cake.

Tannin-based product in feedlot diet as a strategy to reduce enteric methane emissions of Nellore cattle finished under tropical conditions.

A total of 120 Nellore bulls, [initial body weight (BW) = 307 ± 11.6 kg and 12 mo of age] were allocated into 12 collective pens (10 bulls per pen) in a commercial feedlot to evaluate the effects of a specific blend of tannin and saponins on enteric methane (CH4) emissions. The study was a completely randomized design, in which pens were considered the experimental units (N = 6 pens per treatment) and were randomly allocated into one of two treatments: 1) Control (CON), a basal diet with monensin supplementation (25 mg/kg dry matter [DM]; Rumensin, Elanco Animal Health, Greenfield, IN, USA), or 2) Control + a specific blend of tannin and saponins (TAN; 7 g/kg DM; composed of quebracho and chestnut tannin extracts along with carriers from cereals rich in saponins; SilvaFeed BX, Silvateam, San Michele Mondovi, CN, Italy). After the adaptation period (20 d), the experiment was divided into two phases: growing phase (21 to 53 d; total of 33 d) and fattening phase (54 to 139 d; total of 86 d). Enteric methane emissions were estimated using the sulfur hexafluoride (SF6) tracer gas technique. Interactions between treatment and period (growing vs. fattening) were detected for daily CH4 emissions, in which animals fed TAN reduced CH4 emissions by 17.3% during the fattening period compared to bulls fed CON (P = 0.05). In addition, bulls fed TAN had lower CH4 emissions expressed by dry matter intake (DMI) during the fattening period compared to bulls fed CON (P = 0.06). The findings presented herein indicate that a specific blend of tannin and saponins can be used as a strategy to reduce enteric CH4 emissions and its intensity of Nellore bulls finished in feedlot systems under tropical conditions.

Impact of extreme wildfires from the Brazilian Forests and sugarcane burning on the air quality of the biggest megacity on South America.

Recently, extreme wildfires have damaged important ecosystems worldwide and have affected urban areas miles away due to long-range transport of smoke plumes. We performed a comprehensive analysis to clarify how smoke plumes from Pantanal and Amazon forests wildfires and sugarcane harvest burning also from interior of the state of São Paulo (ISSP) were transported and injected into the atmosphere of the Metropolitan Area of São Paulo (MASP), where they worsened air quality and increased greenhouse gas (GHG) levels. To classify event days, multiple biomass burning fingerprints as carbon isotopes, Lidar ratio and specific compounds ratios were combined with back trajectories modeling. During smoke plume event days in the MASP fine particulate matter concentrations exceeded the WHO standard (>25 µg m-3), at 99 % of the air quality monitoring stations, and peak CO2 excess were 100 % to 1178 % higher than non-event days. We demonstrated how external pollution events such as wildfires pose an additional challenge for cities, regarding public health threats associated to air quality, and reinforces the importance of GHG monitoring networks to track local and remote GHG emissions and sources in urban areas.

Implications of CO2 emissions on the main land and forest uses in the Brazilian Amazon.

The emission of soil carbon dioxide (CO2) in agricultural areas is a process that results from the interaction of several factors such as climate, soil, and land management practices. Agricultural practices directly affect the carbon dynamics between the soil and atmosphere. Herein, we evaluated the temporal variability (2020/2021 crop season) of soil CO2 emissions and its relationship with related variables, such as the CO2 flux model, enhanced vegetation index (EVI), gross primary productivity (GPP), and leaf area index (LAI) from orbital data and soil temperature, soil moisture, and soil CO2 emissions from in situ collections from native forests, productive pastures, degraded pastures, and areas of high-yield potential soybean and low-yield potential soybean production. A significant influence (p < 0.01) was observed for all variables and between the different land uses and occupation types. September and October had lower emissions of soil CO2 and low means of soil moisture and soil temperature, and no differences were observed among the treatments. On the other hand, there was a significant effect of the CO2 flux model in productive pastures, high-yield potential soybean areas, and low-yield potential soybean areas. The months with the highest CO2 flux values in the model, regardless of land use and land cover, were October and November, which is the beginning of the rainy season. There were positive correlations between soil CO2 emissions and GPP (0.208), LAI (0.354), EVI (0.363), and soil moisture (0.280) and negative correlations between soil CO2 emissions and soil temperature (-0.240) and CO2 flux model (-0.314) values. Land use and land cover showed negative correlations with these variables, except for the CO2 flux model variable. Soil CO2 emission values were lower for high-yield potential soybean areas (averages from 0.834 to 6.835 µmol m-2 s-1) and low-yield potential soybean areas (from 0.943 to 5.686 µmol m-2 s-1) and higher for native forests (from 2.279 to 8.131 µmol m-2 s-1), whereas the opposite was true for the CO2 flux model.

Evaluation of a Model (RUMINANT) for Prediction of DMI and CH4 from Tropical Beef Cattle.

Simulation models represent a low-cost approach to evaluating agricultural systems. In the current study, the precision and accuracy of the RUMINANT model to predict dry matter intake (DMI) and methane emissions from beef cattle fed tropical diets (characteristic of Colombia) was assessed. Feed intake (DMI) and methane emissions were measured in Brahman steers housed in polytunnels and fed six forage diets. In addition, DMI and methane emissions were predicted by the RUMINANT model. The model's predictive capability was measured on the basis of precision: coefficients of variation (CV%) and determination (R2, percentage of variance accounted for by the model), and model efficiency (ME) and accuracy: the simulated/observed ratio (S/O ratio) and slope and mean bias (MB%). In addition, combined measurements of accuracy and precision were carried out by means of mean square prediction error (MSPE) and correlation correspondence coefficient (CCC) and their components. The predictive capability of the RUMINANT model to simulate DMI resulted as valuable for mean S/O ratio (1.07), MB% (2.23%), CV% (17%), R2 (0.886), ME (0.809), CCC (0.869). However, for methane emission simulations, the model substantially underestimated methane emissions (mean S/O ratio = 0.697, MB% = -30.5%), and ME and CCC were -0.431 and 0.485, respectively. In addition, a subset of data corresponding to diets with Leucaena was not observed to have a linear relationship between the observed and simulated values. It is suggested that this may be related to anti-methanogenic factors characteristic of Leucaena, which were not accounted for by the model. This study contributes to improving national inventories of greenhouse gases from the livestock of tropical countries.

Fuel consumption by agricultural machinery: a review of pollutant emission control technologies / Consumo de combustível por máquinas agrícolas: uma revisão das tecnologias de controle de emissão de poluentes

Most energy used to operate agricultural machines in the field is generated from fossil fuel combustion. The combustion process emits atmospheric pollutants, increasing the emission of greenhouse gases (GHGs). In this context, this review is to discuss technologies for mitigating diesel engine GHG emissions to advance sustainable development in the agricultural machinery sector. This paper presents strategies and technologies widely adopted by agricultural machinery manufacturers in controlling pollutant emissions during fuel combustion. The findings of this study encompass sustainable alternative technologies, such as selective catalytic reduction, exhaust gas recirculation, diesel particulate filter, and fuels. This study helps reveal the environmental impact of agricultural field operations that generate GHG emissions.

Grande parte da energia utilizada para o funcionamento das máquinas agrícolas em suas operações no campo ainda é resultante da combustão de combustíveis fósseis. O processo de combustão provoca a emissão de poluentes atmosféricos que contribuem para o aumento dos Gases de Efeito Estufa (GEE). Neste contexto, esta revisão tem como objetivo descrever as tecnologias que contribuem para mitigar as emissões de GEE pelos motores de ciclo Diesel, a fim de contribuir para a compreensão e o desenvolvimento da sustentabilidade no setor de máquinas agrícolas. São apresentadas as estratégias e tecnologias que comumente estão sendo adotadas pelos fabricantes de máquinas agrícolas para o controle das emissões de poluentes, durante o processo de combustão do combustível. Os achados do estudo apresentam as alternativas tecnológicas sustentáveis como a Selective Catalytic Reduction, Exhaust Gas Recirculation, Diesel Particulate Filter, e sobre o uso de combustíveis alternativos. Ainda, contribui para o entendimento do impacto ambiental das operações agrícolas em campo, que provocam as emissões de GEE.

Fuel consumption by agricultural machinery: a review of pollutant emission control technologies / Consumo de combustível por máquinas agrícolas: uma revisão das tecnologias de controle de emissão de poluentes

ABSTRACT: Most energy used to operate agricultural machines in the field is generated from fossil fuel combustion. The combustion process emits atmospheric pollutants, increasing the emission of greenhouse gases (GHGs). In this context, this review is to discuss technologies for mitigating diesel engine GHG emissions to advance sustainable development in the agricultural machinery sector. This paper presents strategies and technologies widely adopted by agricultural machinery manufacturers in controlling pollutant emissions during fuel combustion. The findings of this study encompass sustainable alternative technologies, such as selective catalytic reduction, exhaust gas recirculation, diesel particulate filter, and fuels. This study helps reveal the environmental impact of agricultural field operations that generate GHG emissions.

RESUMO: Grande parte da energia utilizada para o funcionamento das máquinas agrícolas em suas operações no campo ainda é resultante da combustão de combustíveis fósseis. O processo de combustão provoca a emissão de poluentes atmosféricos que contribuem para o aumento dos Gases de Efeito Estufa (GEE). Neste contexto, esta revisão tem como objetivo descrever as tecnologias que contribuem para mitigar as emissões de GEE pelos motores de ciclo Diesel, a fim de contribuir para a compreensão e o desenvolvimento da sustentabilidade no setor de máquinas agrícolas. São apresentadas as estratégias e tecnologias que comumente estão sendo adotadas pelos fabricantes de máquinas agrícolas para o controle das emissões de poluentes, durante o processo de combustão do combustível. Os achados do estudo apresentam as alternativas tecnológicas sustentáveis como a Selective Catalytic Reduction, Exhaust Gas Recirculation, Diesel Particulate Filter, e sobre o uso de combustíveis alternativos. Ainda, contribui para o entendimento do impacto ambiental das operações agrícolas em campo, que provocam as emissões de GEE.