Predição de frações digestíveis e valor energético de subprodutos agrícolas e agroindustriais para bovinos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of enzyme supplementation of broiler diets based on corn and soybeans

Digestibility of diets based on corn and soybean meal or soybeans treated by roasting or extrusion, with or without an enzyme supplementation, was measured by true (Sibbald) methods, by analysis of excreta, and by analysis of ileal digesta. Only analysis of ileal digesta was able to consistently measure differences between soybean and enzyme treatments in the digestibility of CP, starch, fat, and ME. The amino acid (AA) digestibility of the diets was measured by analysis of the ileal contents. Whereas enzyme supplementation improved overall CP digestibility by 2.9%, this improvement was not equal for all AA. of the AA most important for broilers fed corn-soybean diets, the digestibilities of Lys, Met, and Arg were not improved or not improved significantly by the enzyme supplementation; however, that of Val was improved by 2.3% and that of Thr was improved by 3.0%. A performance trial demonstrated that enzyme supplementation with equal diet formulation improved BW and the feed conversion ratio by 1.9 and 2.2%, respectively. A second performance trial compared standard diet formulations with formulations using enzyme supplementation and energy levels that were reduced by the amount of improvement provided by the inclusion of enzyme in the first performance trial. No difference was seen between treatments, showing that the improvement of nutrient utilization brought about by enzyme supplementation completely compensated for the reduced energy content. Whereas enzyme supplementation should allow a reduction in CP formulation as well, individual AA were not improved equally by supplementation and should also be balanced.

Energetic cost of predation: Aerobic metabolism during prey ingestion by juvenile rattlesnakes, Crotalus durissus

We investigated the cost of prey ingestion in the South American rattlesnake, Crotalus durissus, to see if the capacity to generate energy aerobically could be a constraint on the size of the prey that can be ingested. To accomplish this goal, we measured time and aerobic metabolism (inferred from oxygen consumption) of juvenile C. durissus ingesting prey ranging from 10 to 50% of their own body mass. Time needed for prey ingestion increased with prey size, with prey representing 10 and 20% of snake size being ingested with the same effort. Whole animal rates of oxygen consumption increased linearly with prey size, but at a slower pace for snakes ingesting prey larger than 30% of their body mass. Aerobic factorial power input necessary for prey ingestion increased with prey size, and for snakes ingesting prey representing 50% of their body mass it equaled the aerobic factorial scope for exercise. For the maximum prey size tested, the aerobic derived energy necessary for prey ingestion represented 0.02% of the total energy content of the prey. Within the prey size range we studied, the cost of ingestion did not constitute any constraint on the size of the prey that can be ingested. These constraints are set by morphological (gape size), ecological (predation risk), and, probably, by physiological parameters, as suggested by the tendency of V̇O2 during ingestion to increase at a slower pace at relative larger prey sizes.

Search for semiclassical gravity effects in relativistic stars

We discuss the possible influence of gravity in the neutronization process p+e-→νe, which is particularly important as a cooling mechanism of neutron stars. Our approach is semiclassical in the sense that leptonic fields are quantized on a classical background spacetime, while neutrons and protons are treated as excited and unexcited nucleon states, respectively. We expect gravity to have some influence wherever the energy content carried by the in state is barely above the neutron mass. In this case the emitted neutrinos would be soft enough to have a wavelength of the same order as the space curvature radius. ©2000 The American Physical Society.

Energia de briquetes produzidos com rejeitos de resíduos sólidos urbanos e madeira de Eucalyptus grandis

The incentive for consumption and production in large quantity in modern society generates enormous amounts of urban solid residues in the form of municipal solid waste (MSW). With the intention of reducing these residues of the municipal waste tips and to generate energy, briquettes with mixtures of MSW and residues of Eucalyptus grandis were produced. The briquettes were manufactured with 0, 5, 10, 15, 20 and 25% of MSW in the mixture with wood waste and 12% of moisture content. The analyzed parameters used to choose the best treatments were combustion analysis versus ash content, mechanical strength and energy content. The briquettes up to 10% of MSW showed low resistance, and above 15% showed large increase in ash content. Therefore, the treatment that fulfilled the requirements for combustion versus ash content and mechanical resistance was of at least 15% of MSW, since the source of the ash is unidentified. Considering the net energy content, the best treatment was 25% of MSW, with 17,175 kJ kg-1. Nevertheless, it is strongly advised that further studies related to gas emissions are necessary.

Meal size effects on the postprandial metabolic response of Bothrops alternatus (Serpentes: Viperidae)

We examined the effects of meal size on the postprandial metabolic response of the lancehead Bothrops alternatus (Duméril, Bibron & Duméril, 1894), fed mice equaling to 5, 10, 20, and 40% of the snake's body mass. The maximum O2 consumption rates measured during digestion increased with meal size, reaching levels up to 2.8-7.8-fold higher than the metabolic rate measured during fasting. Specific Dynamic Action (SDA) duration also increased with meal size, lasting from 54 to 212 hours to complete. Under our experimental conditions, 30°C, the majority of our snakes failed to completely digest prey with a relative size of 40%. The SDA coefficient ranged from 17 to 27% of the energy content of the meal and was not affected by meal size. © 2013 Sociedade Brasileira de Zoologia All rights reserved.

Esforço de escavação e teor de lipídios em rainhas da formiga cortadeira Atta sexdens rubropilosa

Nest digging spends a lot of energy existing a question about how much energy is required to dig the tunnel and initial chamber. It was hypothesized that the lipid content is used during nest digging. This hypothesis was tested by comparing the consequences of increasing digging effort in queens that were experimentally stimulated to excavate a complete founding nest either once, twice or three times consecutively, compared to control queens that didn't dig. Weight and lipid content of queens were quantified. Results showed that, in contrast with the initial expectations, weight and lipid content were not affected by the increased digging effort in the experimentally-induced successive excavations. It was conclude that the excavation by the queens did not affect the percentages of lipids and consequently the energy content, in their bodies. Probably, energy resources for the excavation wasn't originated from lipid reserves, but from other energy sources, perhaps carbohydrates.

Formulação não linear de ração para frangos de corte: modelagem e otimização

Pós-graduação em Ciência Animal - FMVA

Nutrientes digestíveis da silagem de grãos úmidos de milho: formulações dietéticas e desempenho de leitões

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exigências de proteína bruta e uso de diferentes níveis de suplementação de selênio orgânico na dieta de perdizes (Rhynchotus rufescens) na fase reprodutiva

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Processing of Brazil-nut flour: characterization, thermal and morphological analysis

A castanha-do-Brasil (Bertholletia excelsea H. B. K.) destaca-se por seus elevados teores em lipídios e proteínas de alta qualidade biológica, parâmetros que justificam a necessidade de maiores pesquisas e incentivos para a elaboração de novos produtos comerciais. No presente estudo, busca-se identificar novas formas de aproveitamento tecnológico dessas amêndoas pela indústria alimentícia, através de seu processamento sobre a forma de farinha sem alteração do teor energético. Os resultados após sua elaboração mostraram um produto com alto valor energético 431,48 kcal.100 g–1, teor de proteína de 45,92 g.100 g–1 e fibra alimentar de 17,14%. As análises térmicas indicam que a introdução de outro componente proteico, como o isolado proteico de soja, não altera as reações e comportamentos térmicos. Já as morfológicas evidenciaram estruturas granulares semelhantes à estrutura das matrizes de proteínas globulares. Constata-se que, após o processamento e obtenção de farinha, o produto mantém seu alto teor energético-proteico e, ao ser submetido a altas temperaturas, mantém suas características.

Análise microbiológica e físico-química de material proteico comestível derivado do processamento da gordura oriunda do abate de bovinos

Background: The use of all by-products of bovine slaughter is of high economic importance for the industries of products of animal origin. Among these products, fat has an important role, once fat rendering may generate several different products, such as protein material that may be used in the manufacture of meat products. However, in spite of the importance that the use of all by-products has for the economic balance of the industry, there are no reports on their use in Brazil, or studies that supply data on microbiological and physical-chemical local standards for this protein. Thus, the objective of this study was to evaluate microbiological and physical-chemical characteristics of protein material obtained from fat rendering, as well as to provide support for companies to use fat rendering to generate protein material, adding value to industrialized meat products.Materials, Methods & Results: The experimental production of edible protein obtained of fat rendering was conducted in slaughterhouse with supervision of the Brazilian Ministry of Agriculture, Livestock and Food Supply. Protein material was obtained in a continuous, humid heat system at high temperatures. Fat scraps containing protein were ground and cooked at high temperature (85 degrees C), and placed in a three phase decanter centrifuge. After centrifugation, protein material was ground again and packed. Samples were collected from 15 batches of protein material, and the following microbiological analyses were carried out: counts of aerobic mesophilic and psychrotrophic microorganisms, coliforms at 35 degrees C, Escherichia coli, sulfite-reducing Clostridium, and Staphylococcus aureus, besides presence or absence of Salmonella and Listeria monocytogens. The following physical-chemical analyses were also carried out: protein, total lipid, moisture, ash, carbohydrate, and energy content. Mean counts of mesophiles, psychrotrophs, and coliforms at 35 degrees C were 4.17; 3.69 and 1.87 (log CFU/g), respectively. Levels of protein, total lipids, moisture, ashes and carbohydrates were 27.50; 7.83; 63.88%; 0.24%; and 0.55%, respectively, and energy content was 182.63 kcal/100g.Discussion: Results of microbiological analyses demonstrated that, although low, the final product showed to be contaminated. Contamination that occurred during the second grinding procedure may be an explanation for these bacterial counts. Also, the temperature used for fat fusion was not enough to eliminate thermoduric microorganisms. However, even with the presence of indicator microorganisms in the samples, none was contaminated by E. coli, sulfite-reducing Clostridium, S. aureus, Salmonella or L. monocytogenes. Physical-chemical analyses showed that the product had adequate nutritional quality. Based on these results, it was possible to conclude that protein material obtained in fat rendering showed characteristics that enable the use of this product as raw material for processed meat products. Besides, the present study was the first one to present scientific results in relation to edible by-products obtained in fat rendering, supplying important information for slaughterhouses and meat-processing plants. The study also produced relevant data on the innocuousness of the product, which may be used to guide decision-making of health inspectors.

Brewer's yeast and sugarcane yeast as protein sources for dogs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Acurácia e precisão na formulação não linear de ração para frangos de corte: avanço e otimização de resultados

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

Biological Hydrogen production from environmental sample in tropical countries

The hydrogen gas is regarded as clean and renewable energy source, since it generates only water during combustion when used as fuel. It shows 2.75 times more energy content than any hydrocarbon and it can be converted into electrical, mechanical energy or heat. Inoculum sources have been successfully tested for hydrogen biological production in temperate climate countries as sludge treatment plants sewage, sludge treatment plant wastewater, landfill sample, among others. However, hydrogen biologic production with inoculum from environmental samples such as sediment reservoirs, especially in tropical countries like Brazil, is rarely investigated. Reservoirs and fresh water lake sediment may contain conditions for the survival of a wide variety of microorganisms which use different carbon sources mainly glucose and xylose, in the fermentation. Glucose is an easily biodegradable, present in most of the industrial effluents and can be obtained abundantly from agricultural wastes. A wide variety of wastewater resulting from agriculture, industry and pulp and paper processed from wood may contain xylose in its constitution. Such effluent contains glucose and xylose concentrations of about 2 g/L. In this sense, this work verified hydrogen biological production in anaerobic batch reactor (1L), at 37 ° C, initial pH 5.5, headspace with N2 (100%), Del Nery medium, vitamins and peptone (1 g/L), fed separately with glucose (2g/L) and xylose (2 g/L). The inoculum was taken from environmental sample (sediment reservoir Itupararanga - Ibiúna - SP-Brazil). It was previously purified in serial dilutions at H2 generation (10-5, 10-7, 10-10), and heat treated (90º C - 10 min) later to inhibited the H2 consumers. The maximum H2 generations obtained in both tests were observed at 552 h, as described below. At the reactors fed with glucose and xylose were observed, respectively, 9.1 and 8.6 mmol H2/L, biomass growth (0.2 and 0.2 nm); consumption of sugar concentrations 53.6% (1.1 glucose g/L) and 90.5% (1.8 xylose g/L); acetic acid generation (124.7 mg/L and 82.7 mg/L), butyric acid (134.0 mg/L and 230.4 mg/L) and there wasn’t methane generation in the reactors. Microscopic analysis of biomass in anaerobic reactors showed the predominance of Gram positive rods and rods with endospores, whose morphology is characteristic of H2-generating bacteria, in both tests. These species were selected from the natural environment. In DGGE analysis performed difference were observed between populations from inoculum and in tests. This analysis confirmed that some species of bacteria were selected which remained under the conditions imposed on the experiment. The efficiency of the pre-treatment of inoculum and the imposition of pH 5.5 inhibited methane-producing microorganisms and the consumers of H2. Therefore, the experimental conditions imposed allowed the attainment of bacterial consortium of producer H2 taken from an environmental sample with concentration of xylose and glucose similar to the ones of the industrial effluents.