963 resultados para Carbon-nutrient balance


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O objetivo nesta pesquisa foi avaliar o efeito de dois ingredientes protéicos da dieta (farelo de soja e de algodão) e de dois processamentos físicos do concentrado (farelado e extrusado) na terminação de 16 bovinos machos não-castrados da raça Canchim. Avaliaram-se ainda a excreção de nutrientes nos dejetos e o potencial de produção de biogás. Os animais tinham 12 meses de idade e 315 kg PC, em média, e foram confinados em baias individuais durante 147 dias (os primeiros 35 dias foram de adaptação). Como volumoso utilizou-se silagem de milho, em uma relação volumoso:concentrado de 50:50, com base na MS. Os resultados foram analisados em delineamento inteiramente casualizado, em esquema fatorial 2 × 2 (fonte protéica × processamento físico). A fonte protéica influenciou o ganho de peso corporal (1,50 e 1,35 kg/dia para o farelo de soja e de algodão, respectivamente), a conversão alimentar (4,73 e 5,31 kg MS ingerida/kg de ganho de peso, respectivamente) e a eficiência protéica (1,78 e 1,59 kg de ganho de peso/kg PB ingerida, respectivamente). O tratamento físico do concentrado e a fonte protéica não influenciaram a ingestão de MS, a área de olho-de-lombo e a espessura de gordura, estimadas por ultra-som. O balanço de nutrientes foi semelhante entre tratamentos para MS, FDN e FDA, mas a fonte protéica determinou diferenças no balanço de PB. Entre os macro e microminerais quantificados nas fezes, os teores de P e Mg diferiram entre as fontes protéicas e a extrusão aumentou o conteúdo de Ca, com médias de 0,39 e 0,43 g/100 g de MS de dejetos, respectivamente, para os concentrados farelado e extrusado. Os dejetos produziram biogás de maneira efetiva entre o 70º e o 200º dia.

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The caprine oxyhemoglobin dissociation curve has not been previously defined. Blood from 10 healthy goats was equilibrated in a tonometer with calibrated gas mixtures of oxygen at concentrations of 95%, 21%, 13%, 12%, 10%, 9%, 8%, 5%, 4% and 2.5%, 5% carbon dioxide, balance nitrogen. The pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), total hemoglobin, oxyhemoglobin saturation, carboxyhemoglobin, methemoglobin, and oxygen content were measured. The PO2/oxyhemoglobin and the PO2/oxygen content relationships were graphed with curve-fitting software and a formula for calculating oxyhemoglobin from PO2 was generated. The maximum oxygen content per gram of hemoglobin was 1.29 ml of oxygen per gram of hemoglobin. The PO2 at which hemoglobin was 50% saturated (P-50) from the PO2/oxyhemoglobin relationship was 28.6 +/- 1.5 mmHg and that from the PO2/oxygen content relationships was 29.1 +/- 1.6 mmHg. The Hill coefficient for the PO2/oxyhemoglobin data was 3.0 +/- 0.4. (c) 2005 Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Metabolic adaptations during negative energy and nutrient balance in dairy cows are thought to cause impaired immune function and hence increased risk of infectious diseases, including mastitis. Characteristic adaptations mostly occurring in early lactation are an elevation of plasma ketone bodies and free fatty acids (nonesterified fatty acids, NEFA) and diminished glucose concentration. The aim of this study was to investigate effects of elevated plasma β-hydroxybutyrate (BHBA) at simultaneously even or positive energy balance and thus normal plasma NEFA and glucose on factors related to the immune system in liver and mammary gland of dairy cows. In addition, we investigated the effect of elevated plasma BHBA and intramammary lipopolysaccharide (LPS) challenge on the mammary immune response. Thirteen dairy cows were infused either with BHBA (HyperB, n=5) to induce hyperketonemia (1.7 mmol/L) or with a 0.9% saline solution (NaCl, n=8) for 56 h. Two udder quarters were injected with 200 μg of LPS after 48 h of infusion. Rectal temperature (RT) and somatic cell counts (SCC) were measured before, at 48 h after the start of infusions, and hourly during the LPS challenge. The mRNA abundance of factors related to the immune system was measured in hepatic and mammary tissue biopsies 1 wk before and 48 h after the start of the infusion, and additionally in mammary tissue at 56 h of infusion (8h after LPS administration). At 48 h of infusion in HyperB, the mRNA abundance of serum amyloid A (SAA) in the mammary gland was increased and that of haptoglobin (Hp) tended to be increased. Rectal temperature, SCC, and mRNA abundance of candidate genes in the liver were not affected by the BHBA infusion until 48 h. During the following LPS challenge, RT and SCC increased in both groups. However, SCC increased less in HyperB than in NaCl. Quarters infused with LPS showed a more pronounced increase of mRNA abundance of IL-8 and IL-10 in HyperB than in NaCl. The results demonstrate that an increase of plasma BHBA upregulates acute phase proteins in the mammary gland. In response to intramammary LPS challenge, elevated BHBA diminishes the influx of leukocytes from blood into milk, perhaps by via modified cytokine synthesis. Results indicate that increased ketone body plasma concentrations may play a crucial role in the higher mastitis susceptibility in early lactation.

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An experiment was conducted to investigate the effects of increasing the level of two sources of fibrous by-products, orange pulp (OP) and carob meal (CM), in iso-NDF growing-finishing pig diets on nutrient balance, slurry composition and potential ammonia (NH3) and methane (CH4) emissions. Thirty pigs (85.4 ± 12.3 kg) were fed five iso-nutritive diets: a commercial control wheat/barley (C) and four experimental diets including two sources of fibrous by-products (OP and CM) and two dietary levels (75 and 150 g/kg) in a 2 × 2 factorial arrangement. After a 14-day adaptation period, faeces and urine were collected separately for 7 days to measure nutrient digestibility and the excretory patterns of N from pigs (6 replicates per diet) housed individually in metabolic pens. For each animal, the derived NH3 and CH4 emissions were measured in samples of slurry over an 11- and 100-day storage periods, respectively. Source and level of the fibrous by-products affected digestion efficiency in a different way as the coefficients of total tract apparent digestibility (CTTAD) for dry matter (DM), organic matter (OM), fibre fractions and gross energy increased with OP but decreased with CM (P < 0.05). Crude protein CTTAD decreased with the inclusion of both sources of fibre, being lower at the highest dietary level. Faecal concentration of fibre fractions increased (P < 0.05) with the level of inclusion of CM but decreased with that of OP (P < 0.01). High dietary level for both sources of fibre increased (P < 0.02) CP faecal content but urine N content decreased (from 205 to 168 g/kg DM, P < 0.05) in all the fibre-supplemented compared to C diet. Additionally, the proportions of undigested dietary, water soluble, and bacterial and endogenous debris of faecal N excretion were not affected by treatments. The initial slurry characteristics did not differ among different fibre sources and dietary levels, except pH, which decreased at the highest by-product inclusion levels. Ammonia emission per kg of slurry was lower in all the fibre-supplemented diets than in C diet (from 2.44 to 1.81 g, P < 0.05). Additionally, slurries from the highest dietary level of by-products tended (P < 0.06) to emit less NH3 per kg of initial total Kjeldahl N and showed a lower B0, independently of the fibre source. Thus, the fibre sources and their dietary levels affected pig nutrient digestion and composition of urine and faeces, showing potential to decrease NH3 and CH4 emissions at high levels of inclusion, independently of type of fibre.

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Dietary modification is considered a cornerstone in the management of diabetes superimposed upon which are pharmacological therapies as required. The value of hypocaloric diets in reducing and eliminating glycosuria was extolled in the pre-insulin era. A common feature of the nutrient balance of these diets was restriction in the availability of carbohydrate. Herein we review the use of diet as therapy in the past and discuss the rationale for hypocaloric dietary management of type 2 diabetes in the 21st century, drawing comparisons with bariatric surgery and considering why weight loss is particularly difficult for overweight and obese individuals with type 2 diabetes. © SAGE Publications 2012.

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The ageing process is strongly influenced by nutrient balance, such that modest calorie restriction (CR) extends lifespan in mammals. Irisin, a newly described hormone released from skeletal muscles after exercise, may induce CR-like effects by increasing adipose tissue energy expenditure. Using telomere length as a marker of ageing, this study investigates associations between body composition, plasma irisin levels and peripheral blood mononuclear cell telomere length in healthy, non-obese individuals. Segmental body composition (by bioimpedance), telomere length and plasma irisin levels were assessed in 81 healthy individuals (age 43∈±∈15.8 years, BMI 24.3∈±∈2.9 kg/m2). Data showed significant correlations between log-transformed relative telomere length and the following: age (p∈<∈0.001), height (p∈=∈0.045), total body fat percentage (p∈=∈0.031), abdominal fat percentage (p∈=∈0.038) , visceral fat level (p∈<∈0.001), plasma leptin (p∈=∈0.029) and plasma irisin (p∈=∈0.011), respectively. Multiple regression analysis using backward elimination revealed that relative telomere length can be predicted by age (b∈=∈-0.00735, p∈=∈0.001) and plasma irisin levels (b∈=∈0.04527, p∈=∈0.021). These data support the view that irisin may have a role in the modulation of both energy balance and the ageing process. © 2014 The Author(s).

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Three conical sediment were deployed at three depths 968 m (top trap), 1976 m (middletrap), and 2938 m (50mabove the bottom, bottom trap) - from June 27, 2004 to April 27, 2005 on the NW Atlantic margin at a water depth of 2988 m. The sediment trap carousels were programmed to open each collection cup for 23.4 days for the top trap and 14.5 days for the other two traps, resulting in total 13 samples from the top trap and 21 samples each from the middle and bottom traps. The samples were analyzed for the biogeochemical properties with various methods. Frequent occurrences of higher fluxes in deep relative to shallower sediment traps and low delta 14C values of sinking POC together provide strong evidence for significant lateral transport of aged organic matter over the margin. Comparison of biogeochemical properties such as aluminum concentration and flux, and iron concentration between samples intercepted at different depths shows that particles collected by the deepest trap had more complex sources than the shallower ones. These data also suggest that at least two modes of lateral transport exist over the New England margin. Based on radio carbon mass balance, about 30% (± 10%) of sinking POC in all sediment traps is estimated to be derived from lateral transport of re-suspended sediment. A strong correlation between delta 14C values and aluminum concentrations suggests that the aged organic matter is associated with lithogenic particles.

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Dissertação de Mestrado, Engenharia Agronómica, 20 de Julho de 2016, Universidade dos Açores.

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Ocean acidification has a wide-ranging potential for impacting the physiology and metabolism of zooplankton. Sufficiently elevated CO2 concentrations can alter internal acid-base balance, compromising homeostatic regulation and disrupting internal systems ranging from oxygen transport to ion balance. We assessed feeding and nutrient excretion rates in natural populations of the keystone species Euphausia superba (Antarctic krill) by conducting a CO2 perturbation experiment at ambient and elevated atmospheric CO2 levels in January 2011 along the West Antarctic Peninsula (WAP). Under elevated CO2 conditions (~672 ppm), ingestion rates of krill averaged 78 µg C/individual/d and were 3.5 times higher than krill ingestion rates at ambient, present day CO2 concentrations. Additionally, rates of ammonium, phosphate, and dissolved organic carbon (DOC) excretion by krill were 1.5, 1.5, and 3.0 times higher, respectively, in the high CO2 treatment than at ambient CO2 concentrations. Excretion of urea, however, was ~17% lower in the high CO2 treatment, suggesting differences in catabolic processes of krill between treatments. Activities of key metabolic enzymes, malate dehydrogenase (MDH) and lactate dehydrogenase (LDH), were consistently higher in the high CO2 treatment. The observed shifts in metabolism are consistent with increased physiological costs associated with regulating internal acid-base equilibria. This represents an additional stress that may hamper growth and reproduction, which would negatively impact an already declining krill population along the WAP.

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Develop a superior fertiliser product (compared to conventional spent litter and current palletised forms) formulated from poultry litter.

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The potential for fertiliser use in Lockyer Valleys intensive vegetable production to impact on the Moreton Bay Waterways (MBW) is not well defined. Notwithstanding nutrient runoff through soil erosion of agricultural lands has been identified as a process that significantly contributes artificial fertiliser to the MBW (SEQ Healthy Waterways Draft Strategy 2006). In order to better understand this issue the present study undertakes a nutrient mass balance to evaluate nitrogen use efficiency in the intensive horticultural industry of the Lockyer Valley.