10 research outputs found

    Metabolismo da pectina em animais ruminantes - uma revisão

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    As pectinas são substâncias encontradas em subprodutos da indústria de extração de sucos de frutas — como a polpa de laranjas e maçãs — e da extração de açúcar — como a polpa de beterraba —, e fazem parte dos componentes da parede celular, atuando como cimento entre as células. A pectina é o único componente da parede celular que é completamente e rapidamente fermentável e, portanto, não é uma substância lignificada. Outra grande vantagem é que a fermentação da pectina não produz ácido láctico no ambiente ruminal, resultando em características fermentativas semelhantes às espécies forrageiras e contrárias aos açúcares que são rapidamente fermentados a lactato. Em virtude dessas características benéficas, a inclusão de subprodutos ricos em pectina na dieta de animais ruminantes poderá melhorar a digestibilidade da maioria dos nutrientes, por proporcionar um ambiente ruminal saudável, ao contrário do que ocorre com fontes ricas em amido, cujo padrão de fermentação diminui o pH ruminal, tornando os ruminantes propensos a distúrbios metabólicos como a acidose ruminal e o timpanismo, em sistemas intensivos

    Aerosol Particle and Black Carbon Emission Factors of Vehicular Fleet in Manila, Philippines

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    Poor air quality has been identified as one of the main risks to human health, especially in developing regions, where the information on physical chemical properties of air pollutants is lacking. To bridge this gap, we conducted an intensive measurement campaign in Manila, Philippines to determine the emission factors (EFs) of particle number (PN) and equivalent black carbon (BC). The focus was on public utility jeepneys (PUJ), equipped with old technology diesel engines, widely used for public transportation. The EFs were determined by aerosol physical measurements, fleet information, and modeled dilution using the Operational Street Pollution Model (OSPM). The results show that average vehicle EFs of PN and BC in Manila is up to two orders of magnitude higher than European emission standards. Furthermore, a PUJ emits up to seven times more than a light-duty vehicles (LDVs) and contribute to more than 60% of BC emission in Manila. Unfortunately, traffic restrictions for heavy-duty vehicles do not apply to PUJs. The results presented in this work provide a framework to help support targeted traffic interventions to improve urban air quality not only in Manila, but also in other countries with a similar fleet composed of old-technology vehicles

    <b>Fontes de gordura ômega-3 e ômega-6 sobre a digestibilidade aparente de novilhas de corte confinadas</b> - DOI: 10.4025/actascianimsci.v26i3.1834 <b>Fat source Omega 3, Omega 6 apparent digestibility of nelore beef heifers</b> - DOI: 10.4025/actascianimsci.v26i3.1834

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    O objetivo desse trabalho foi avaliar o efeito da suplementação com diferentes fontes de gordura sobre a digestibilidade aparente da matéria seca (MS), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose (HEM) e matéria orgânica (MO). Foram utilizadas 23 novilhas &frac12; Red Angus e &frac12; Nelore, com 20 meses de idade e peso médio inicial de 351kg, durante 28 dias, distribuídas ao acaso em 3 tratamentos: suplementação com semente de linho, fonte de ômega-3 (LIN); suplementação com gordura protegida, fonte de ômega-6 (GOP - Lac100&reg;) e sem suplementação com gordura (SGO). A cinza insolúvel em ácido foi utilizada como indicador interno. As digestibilidades aparentes da FDN e FDA (61,02% e 56,05%, respectivamente) não foram afetadas pelas fontes de gordura. As digestibilidades da MS e da MO foram maiores para as dietas LIN (69,23% e 70,95%) e GOP (69,69% e 72,57%) em relação à SGO (67,39% e 68,28%). Para a digestibilidade da PB, o LIN foi superior ao SGO, mas o GOP não diferiu deste. A GOP promoveu maior digestibilidade do EE em comparação ao LIN e este foi superior ao SGO e, o LIN apresentou maior digestibilidade da HEM, em relação aos demais.<br>The aim of this research was to evaluate the effect of different fat sources supplements on apparent digestibility of dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicelluloses (HEM), and organic matter (OM). Twenty three 20 months old and 351 kg of initial body weight crossbreed heifers (&frac12; Red Angus &frac12; Nelore) were used during 28 days. The heifers were allotted into a completely randomized design in three different treatments: Linseed supplement, omega-3 source (LIN); Protected fat, omega-6 source (PFA), and No fat supplement (NOF). The acid insoluble ash was used as internal indicator. NDF and ADF apparent digestibility (61.02% and 56.05%, respectively) were not affected by fat sources. DM and OM digestibility were higher for LIN (69.23% and 70.95%) and PFA (69.69% and 72.57%) diets in relation to NOF (67.39% and 68.28%). For CP digestibility, LIN was higher than NOF, but PFA did not differ from these. PFA promoted higher EE digestibility compared with LIN and this was higher to NOF. LIN presented higher HEM digestibility in relation to the others

    Fat supplementation ("Flushing") on the postpartum beef cows submitted to early weaning: performance Suplementação com gordura ("Flushing") para vacas de corte no pós-parto submetidas ao desmame precoce: desempenho animal

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    The effects of short-time fat supplementation flushing on animal performance (final body weight and average daily gain) of postpartum beef cows, submitted to the early weaning were evaluatrd. Two hundred and fifty eight beef cows from the following genetic groups were used: Aberdeen Angus (n = 21), Aberdeen Angus x Canchim (n = 20), Canchim x Aberdeen Angus (n = 52), Charoles x Caracu (n = 29), Charolês (n = 18), Cachim (n = 34), Caracu (n = 35), Caracu x Charoles (n = 26) and Purunã (n = 23), with 418.1±14.0 kg of body weight and pregnant. These animals were split into two treatments: flushing (30% soybean grain + 70% corn ground grain) and without supplementation. There was no flushing effect on final body weight (436.6 kg) and average daily gain (0.83 kg). November period, cows had higher final body weight (441.6 kg) and average daily gain (1.01 kg). There was no effect of flushing on variables.<br>O objetivou-se, neste experimento, avaliar o efeito da suplementação de gordura por um curto período de tempo (flushing) sobre o desempenho animal (peso vivo final e ganho médio diário) de fêmeas de corte no pós-parto, submetidas ao desmame precoce. Foram utilizadas 258 vacas, dos grupos genéticos: Aberdeen Angus (n = 21), Aberdeen Angus x Canchim (n = 20), Canchim x Aberdeen Angus (n = 52), Charolês x Caracu (n = 29), Charolês (n = 18), Cachim (n = 34), Caracu (n = 35), Caracu x Charolês (n = 26) e Purunã (n = 23), com peso vivo médio de 418,1±14,0 kg e diagnóstico de prenhez positivo. Os animais foram distribuídos nos tratamentos flushing (30% de grão de soja + 70% de milho grão moído) e não suplementados. Foram avaliados três períodos de acordo com a ordem de parição: setembro, outubro e novembro. Não houve efeito do flushing sobre o peso vivo final (436,6 kg) e ganho médio diário (0,83 kg). O período de novembro apresentou maior peso vivo final (441,6 kg) e ganho médio diário (1,01 kg). O fornecimento de gordura (flushing) para fêmeas de corte no pós-parto não resultou em ganhos de peso vivo

    Fat sources omega-3 and omega-6 on voluntary feed intake of feedlot beef heifers/ <br> Fontes de gordura ômega-3 e ômega-6 sobre o consumo voluntário de novilhas de corte confinadas

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    The objective of this work was to evaluate the effect of different fat sources supplements on voluntary intake of dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicelluloses (HEM), and organic matter (OM). Twenty-four crossbreed heifers (½ Red Angus ½ Nelore) 20 months old and 351 kg of initial body weight were used during 56 days. The heifers were allotted in a completely randomized design for three different treatments: linseed supplement, omega-3 source (LIN); protected fat, omega-6 source (PFA), and no fat supplement (NOF). There was no difference (P < 0.05) on DM, CP, NDF, ADF, and OM voluntary intake, expressed in kg/day, % BW and g/ kg BW0,75 for fat sources. The values means of dry matter voluntary intake were 8.51 kg/day, 2.43% BW, and 105.12 g/kg BW0,75. Heifers on treatment LIN and PFA presented highest (P<0.05) EE intake, expressed in kg/day, %BW and g/kg BW0,75. The LIN treatment resulted in highest (P < 0.05) HEM intake in % BW and g/kg BW0,75.<p><p>O objetivo deste trabalho foi avaliar o efeito da suplementação com diferentes fontes de gordura sobre o consumo voluntário de matéria seca (MS), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose (HEM) e matéria orgânica (MO). Foram utilizadas 24 novilhas (½ Red Angus e ½ Nelore), com 20 meses de idade e peso médio inicial de 351 kg, durante 56 dias, distribuídas ao acaso em três tratamentos: suplementação com semente de linho, fonte de ômega-3 (LIN); suplementação com gordura protegida, fonte de ômega-6 (GOP - Lac100ÆÊ) e sem suplementação com gordura (SGO). Não houve diferença (p > 0,05) no consumo voluntário de MS, PB, FDN, FDA e MO, expressos em kg/dia, %PV e g/kg PV0,75 para as fontes de gordura testadas, sendo observado valores médios de consumo de MS de 8,51 kg/dia, 2,43% do PV e 105,12 g/kg PV0,75, respectivamente. As novilhas do tratamento LIN e GOP apresentaram maiores (p < 0,05) consumos de EE, expressos em kg/dia, %PV e g/kg PV0,75. O LIN resultou em maior (p < 0,05) consumo de HEM em %PV e g/kg PV0,75

    Respiratory tract deposition of inhaled roadside ultrafine refractory particles in a polluted megacity of South-East Asia

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    Recent studies demonstrate that Black Carbon (BC) pollution in economically developing megacities remain higher than the values, which the World Health Organization considers to be safe. Despite the scientific evidence of the degrees of BC exposure, there is still a lack of understanding on how the severe levels of BC pollution affect human health in these regions. We consider information on the respiratory tract deposition dose (DD) of BC to be essential in understanding the link between personal exposure to air pollutants and corresponding health effects. In this work, we combine data on fine and ultrafine refractory particle number concentrations (BC proxy), and activity patterns to derive the respiratory tract deposited amounts of BC particles for the population of the highly polluted metropolitan area of Manila, Philippines. We calculated the total DD of refractory particles based on three metrics: refractory particle number, surface area, and mass concentrations. The calculated DD of total refractory particle number in Metro Manila was found to be 1.6 to 17 times higher than average values reported from Europe and the U.S. In the case of Manila, ultrafine particles smaller than 100 nm accounted for more than 90% of the total deposited refractory particle dose in terms of particle number. This work is a first attempt to quantitatively evaluate the DD of refractory particles and raise awareness in assessing pollution-related health effects in developing megacities. We demonstrate that the majority of the population may be highly affected by BC pollution, which is known to have negative health outcomes if no actions are taken to mitigate its emission. For the governments of such metropolitan areas, we suggest to revise currently existing environmental legislation, raise public awareness, and to establish supplementary monitoring of black carbon in parallel to already existing PM 10 and PM 2.5 measures. © 201

    Spatial Characterization of Black Carbon Mass Concentration in the Atmosphere of a Southeast Asian Megacity: An Air Quality Case Study for Metro Manila, Philippines

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    Black carbon (BC) particles have gathered worldwide attention due to their impacts on climate and adverse health effects on humans in heavily polluted environments. Such is the case in megacities of developing and emerging countries in Southeast Asia, in which rapid urbanization, vehicles of obsolete technology, outdated air quality legislations, and crumbling infrastructure lead to poor air quality. However, since measurements of BC are generally not mandatory, its spatial and temporal characteristics, especially in developing megacities, are poorly understood. To raise awareness on the urgency of monitoring and mitigating the air quality crises in megacities, we present the results of the first intensive characterization experiment in Metro Manila, Philippines, focusing on the spatial and diurnal variability of equivalent BC (eBC). The average mass concentration of eBC at the urban background station (UBS) was 7.0 ± 4.8 µg m–3 while at roadside (RS), hourly concentrations reached maximum values of 138 µg m–3, levels that are significantly higher than in European cities. At RS, the diurnal cycles of eBC mass concentration were connected most strongly with traffic dynamics and street configuration, while a notable influence of planetary boundary layer evolution was observed in the UBS. Results of mobile measurements conducted multiple times along two fixed routes showed high spatial variability ranging from 3–80 µg m–3 within a 500-m radius. Alarmingly, the highest concentrations were found in the most crowded areas where people spend more than eight hours a day

    Aerosol particle mixing state, refractory particle number size distributions and emission factors in a polluted urban environment: Case study of Metro Manila, Philippines

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    Ultrafine soot particles (black carbon, BC) in urban environments are related to adverse respiratory and cardiovascular effects, increased cases of asthma and premature deaths. These problems are especially pronounced in developing megacities in South-East Asia, Latin America, and Africa, where unsustainable urbanization ant outdated environmental protection legislation resulted in severe degradation of urban air quality in terms of black carbon emission. Since ultrafine soot particles do often not lead to enhanced PM10 and PM2.5 mass concentration, the risks related to ultrafine particle pollution may therefore be significantly underestimated compared to the contribution of secondary aerosol constituents. To increase the awareness of the potential toxicological relevant problems of ultrafine black carbon particles, we conducted a case study in Metro Manila, the capital of the Philippines. Here, we present a part of the results from a detailed field campaign, called Manila Aerosol Characterization Experiment (MACE, 2015). Measurements took place from May to June 2015 with the focus on the state of mixing of aerosol particles. The results were alarming, showing the abundance of externally mixed refractory particles (soot proxy) at street site with a maximum daily number concentration of approximately 15000 #/cm3. That is up to 10 times higher than in cities of Western countries. We also found that the soot particle mass contributed from 55 to 75% of total street site PM2.5. The retrieved refractory particle number size distribution appeared to be a superposition of 2 ultrafine modes at 20 and 80 nm with a corresponding contribution to the total refractory particle number of 45 and 55%, respectively. The particles in the 20 nm mode were most likely ash from metallic additives in lubricating oil, tiny carbonaceous particles and/or nucleated and oxidized organic polymers, while bigger ones (80 nm) were soot agglomerates. To the best of the authors\u27 knowledge, no other studies reported such high number concentration of ultrafine refractory particles under ambient conditions. Inverse modeling of emission factors of refractory particle number size distributions revealed that diesel-fed public utility Jeepneys, commonly used for public transportation, are responsible for 94% of total roadside emitted refractory particle mass. The observed results showed that the majority of urban pollution in Metro Manila is dominated by carbonaceous aerosol. This suggests that PM10 or PM2.5 metrics do not fully describe possible health related effects in this kind of urban environments. Extremely high concentrations of ultrafine particles have been and will continue to induce adverse health related effects, because of their potential toxicity. We imply that in megacities, where the major fraction of particulates originates from the transport sector, PM10 or PM2.5 mass concentration should be complemented by legislative measurements of equivalent black carbon mass concentration
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