936 resultados para Feeds and feeding. Animal nutrition
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The use of laboratory animals in conjunction with research on the human organism provides a basis for on understanding of several important physiological and pathological processes. Besides, the results of experimental studies enable technical and safety improvements to be made in surgical techniques used in the medical clinic. As living biological material is involved, we should guarantee its physical well-being, taking into account microbiological contamination and the genetics, nutrition and correct manipulation of the animals, in order to avoid incorrect conclusions from the experiments or unnecessarily large numbers of animals being used. In parallel with the concerns and legislation on the use of laboratory animals, there is also a growing preoccupation with the welfare and safety of those who handle the laboratory animals, since they run the risk of acquiring occupational diseases through contact with zoonotic pathogens or developing allergies. Prevention requires the application of modern technological advances in the design of the animal house and in the work routines. Unfortunately, few establishments in Brazil possess staff with adequate training and a basic infrastructure of research that includes the laboratory animal breeding centers, equivalent to those existing ones in the United States and Europe.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Nile tilapia (Oreochromis niloticus), which is exotic to South America, is the most common species caught in artisanal fisheries at the Barra Bonita Reservoir, Southeastern Brazil. This species is of great socioeconomic importance for the region and keeps active a population of about 500 fishers. In the present study we assess reproduction, food dynamics and level of exploitation of O. niloticus, caught by artisanal fisheries in the Barra Bonita Reservoir. Specimens were collected monthly, from July 2004-June 2005, and a total of 1 715 specimens were analyzed. Each specimen was examined to obtain biological and biometric data: standard length (cm), total weight (g), reproductive data (sex and stage of maturation), and stomach contents (empty, partly full, and full). We also estimated the sex ratio (by macroscopic observation of gonads), reproductive period (by ovarian development and seasonal average of gonadosomatic index in females), and feeding habits (by stomach contents). The possible relationship between abiotic factors and the reproductive period was statistically verified using Spearman's Rank Correlation. The FiSAT (ELEFAN I) package was used to assess growth parameters, mortality rates and to infer exploitation rate from standard length frequencies. The O. niloticus population had a sex ratio of 1.3:1 (M:F). Results indicated that ripe females were captured throughout the year, with a higher frequency during the winter-2004 (with a frequency of 59%, at a mean temperature of 20.5°C), and in spring-2004 (with a frequency of 60.5% at a mean temperature of 21.18°C). The GSI mean values obtained by season were: winter-2004: 1.71; spring-2004: 1.72; summer-2005: 0.80, and autumn-2005: 1.19. The Spearman correlation indicated positive values with respect to pH, dissolved oxygen, electric conductivity, transparency and chlorophyll a, and negative values with respect to temperature, accumulated rainfall and altimetric benchmark. The main food items were phytoplankton and periphytic algae, observed in 99.6% of the analyzed stomachs. The estimated growth and mortality parameters were: L∞=33.60cm, k=0.63/year, longevity= 4.76years, Z=2.81/ year, M=1.20/year and F=1.61/year. The weight-length relationship was Ln Wt=-2.8532+2.8835 Ln Lp. The estimated yield per recruit values were as follows: E=0.570, Emax=0.776, E0.1=0.604 and E0.5=0.349. These results indicate that a well established population of O. niloticus is present at Barra Bonita Reservoir; with an active reproduction throughout the year, more intense during winter and spring, and that O. niloticus is a phytoplanktophagus species. There were no indications that this species is being overfished, we therefore recommend that, due to its exotic condition, no restrictions need to be taken on its fishing activities.
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Background: Staphylococcus is a clinically important genus because of its capacity to produce enterotoxins and to cause food poisoning. Staphylococci are the most frequent microorganisms of the skin and mucosal microbiota, with an estimated 20 to 40% of individuals carrying these bacteria on their hands or nose. Since nutrition professionals are involved in the handling and preparation of foods and are possible carriers of these bacteria, the objective of this study was to investigate the presence of Staphylococcus on the hands and in the nasal fossae of undergraduate nutrition students and to determine the enterotoxigenic capacity of these microorganisms. Methods and Findings: A total of 201 strains were isolated from the hands and nose of 61 nutrition students. Of these, 180 (89.5%) were identified as coagulasenegative staphylococci and 21 (10.5%) as S. aureus. Thirty-seven (18.4%) Staphylococcus isolates were producers of enterotoxin A. Toxin production was detected in 5 (19%) of the S. aureus isolates and in 31 (17.2%) of the coagulase-negative staphylococci. Conclusions: This study demonstrated a large number of enterotoxin-producing staphylococci on the hands and nose of nutrition students and professionals involved in the handling and preparations of foods. These findings indicate the need for adequate hygiene measures to prevent food poisoning. © iMedPub.
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The aim of this research was to evaluate the intake and apparent digestibility of nutrients in sheep fed with diets containing different amounts of linseed meal. The treatments evaluated were: corn silage exclusive (control); corn silage + concentrate; corn silage + concentrate + 5% of linseed meal; corn silage + concentrate + 10% of linseed meal. The dry matter (DM) intake has increased in diets containing concentrated if compared to diet exclusively with corn silage (P<0.05), however, there was no effect of the inclusion of linseed meal in diets (0; 5 and 10%). As it was expected, the diets containing 5 and 10% of linseed meal resulted in an increase of ether extract (EE) intake. A higher apparent digestibility of DM, organic matter (OM) and neutral detergent fiber (NDF) in the animals fed with diets containing the concentrate was observed, independently of linseed meal proportion. According to the experimental conditions under which the experiment was developed, itis recommended to provide the diets containing until 5% of linseed meal, because there is no negative effect on dry matter and nutrients intake, as well as on apparent digestibility.
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The effects of exogenous enzymes supplementation on kibble diets for dogs formulated with soybean meal (SBM) as a substitute for poultry by-product meal (PM) was investigated on nutrient digestibility, fermentation products formation, post-prandial urea response and selected faecal bacteria counts. Two kibble diets with similar compositions were used in two trials: PM-based diet (28.9% of PM; soybean hulls as a fibre source) and SBM-based diet (29.9% of SBM). In experiment 1, the SBM diet was divided into three diets: SBM-0, without enzyme addition; SBM-1, covered after extrusion with 7500U protease/kg and 45U cellulase/kg; and SBM-2, covered with 15000U protease/kg and 90U cellulase/kg. In experiment 2, the SBM diet was divided into three diets: SBM-0; SBM-1, covered with 140U protease/kg; 8U cellulase/kg, 800U pectinase/kg, 60U phytase/kg, 40U betaglucanase/kg and 20U xylanase/kg; and SMB-2, covered with 700U protease/kg, 40U cellulase/kg, 4000U pectinase/kg, 300U phytase/kg, 200U betaglucanase/kg and 100U xylanase/kg. Each experiment followed a block design with six dogs per diet. Data were submitted to analysis of variance and means compared by orthogonal and polynomial contrasts (p<0.05). In both experiments, nutrients and energy digestibility did not differ between diets (p>0.05). SBM consumption resulted in increased faecal moisture and production (p<0.05), without effect on faecal score. Higher concentration of propionate, acetate and lactate, and lower ammonia and pH were found in the faeces of dogs fed SBM (p<0.05). Higher post-prandial urea was verified in dogs fed SBM (p<0.05). In experiment 2, the addition of enzymes increased faecal concentration of propionate, acetate and total short-chain fatty acid (p<0.05) and tended to reduce post-prandial urea concentration (p=0.06). Although with similar digestibility, SBM shows a worse utilization of absorbed amino acids than the PM. Soybean oligosaccharides can beneficially change gut fermentation product formation. Enzymes can increase the gut fermentation activity and improve the SBM proteic value. © 2013 Blackwell Verlag GmbH.
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Bos indicus bulls 20. months of age grazed on pasture in Minas Gerais, Brazil either received 2 doses of the GnRF vaccine Bopriva at d0 and d91 (group IC, n. =. 144) or were surgically castrated on d91 (group SC, n. =. 144). Slaughter on d280, was 27. weeks after castration. Adverse safety issues in 8% of group SC bulls following surgery contrasted with 0% in group IC bulls. At d105 testosterone levels were suppressed to similar levels in both groups. Importantly, group IC bulls had higher live weight, hot carcass weight, ADG (P<. 0.005) and dressing percentage (P<. 0.0001) compared to group SC animals. There were no negative effects on carcass or meat quality traits, thus immunocastration was concluded to offer a safe and effective method that provides production gains, and improves animal welfare in Bos indicus beef bulls without impacting meat and carcass quality. © 2013 Elsevier Ltd.
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Ractopamine is a β-adrenergic agonist used as an energy repartitioning agent in the diets of finishing pigs. Most ractopamine studies are limited to evaluations of growth performance and meat quality, and there is little information on the effects of this additive on the behavior and welfare of pigs. Therefore, the objective of this study was to evaluate various indicators of stress caused by feeding diets containing ractopamine. One hundred seventy barrows and 170 gilts weighing 107.3 kg were allocated to 30 pens with 10 to 12 barrows or gilts per pen. Pigs were offered 1 of the 3 dietary treatments (0, 5, or 10 mg ractopamine/kg) for 28 d with 5 barrow pens and 5 gilt pens per treatment. Pigs were evaluated for behavior 3 d per week 1 wk before the initiation of the experiment and throughout the experiment. Each pig was classified into 1 of the 13 activities (drinking water, lying alone, lying in clusters, standing, nosing pig, sitting, feeding, biting pig, walking, exploring, running away, playing, and mounting pen mates) and also grouped into 1 of the 3 categories (calm, moving, and feeding themselves) based on those activities. At the end of the experiment, 3 pigs from each pen were slaughtered, and blood samples were collected during exsanguination to determine physiological indicators of stress (cortisol, lactate, and creatine-kinase enzymes). The incidence of skin and carcass lesions was determined at shoulder, loin, and ham. Ractopamine had no effect (P > 0.05) on pig behavior, total number of skin and carcass lesions, or blood concentrations of cortisol or lactate. However, there was an increase (P < 0.05) of creatine kinase concentrations in pigs receiving ractopaminesupplemented feed. This finding is consistent with the concept that ractopamine may cause muscular disorders, and this warrants further investigation. © 2013 American Society of Animal Science. All rights reserved.
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The objectives of the present study were to estimate genetic parameters of monthly test-day milk yield (TDMY) of the first lactation of Brazilian Holstein cows using random regression (RR), and to compare the genetic gains for milk production and persistency, derived from RR models, using eigenvector indices and selection indices that did not consider eigenvectors. The data set contained monthly TDMY of 3,543 first lactations of Brazilian Holstein cows calving between 1994 and 2011. The RR model included the fixed effect of the contemporary group (herd-month-year of test days), the covariate calving age (linear and quadratic effects), and a fourth-order regression on Legendre orthogonal polynomials of days in milk (DIM) to model the population-based mean curve. Additive genetic and nongenetic animal effects were fit as RR with 4 classes of residual variance random effect. Eigenvector indices based on the additive genetic RR covariance matrix were used to evaluate the genetic gains of milk yield and persistency compared with the traditional selection index (selection index based on breeding values of milk yield until 305 DIM). The heritability estimates for monthly TDMY ranged from 0.12 ± 0.04 to 0.31 ± 0.04. The estimates of additive genetic and nongenetic animal effects correlation were close to 1 at adjacent monthly TDMY, with a tendency to diminish as the time between DIM classes increased. The first eigenvector was related to the increase of the genetic response of the milk yield and the second eigenvector was related to the increase of the genetic gains of the persistency but it contributed to decrease the genetic gains for total milk yield. Therefore, using this eigenvector to improve persistency will not contribute to change the shape of genetic curve pattern. If the breeding goal is to improve milk production and persistency, complete sequential eigenvector indices (selection indices composite with all eigenvectors) could be used with higher economic values for persistency. However, if the breeding goal is to improve only milk yield, the traditional selection index is indicated. © 2013 American Dairy Science Association.
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The study is aimed to evaluate the efficiency of ultrasound-assisted extraction (UAE) as a simple strategy focused on sample preparation for metal determination in biological samples. The extraction of sodium and potassium extraction was carried out from swine feed followed by determination of the concentration of these metals by flame atomic emission spectrometry (FAES). The experiment was performed to cover the study of the variables influencing the extraction process and its optimal conditions (sample mass, particle size, acid concentration, sonication time and ultrasound power); the determination of these analytical characteristics and method validation using certified reference material; and the analysis of pre-starter diets. The optimal conditions established conditions were as follows: mass: 100 mg, particle size:<60 μm, acid concentration: 0.10 mol L-1 HCl, sonication time: 50 s and ultrasound power: 102 W. The proposed method (UAE) was applied in digestibility assays of those nutrients present in different piglet pre-starter feeds and their results proved to be compatible with those obtained from mineralized samples (P < 0.05). The ultrasound extraction method was demonstrated to be an excellent alternative for handless sampling and operational costs and the method also has the advantage of does not generating toxic residues that may negatively affect human health and contaminate the environment. © 2013 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Alimentos e Nutrição - FCFAR
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Pós-graduação em Medicina Veterinária - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)