Enzyme production by solid-state fermentation: Application to animal nutrition

Many microorganisms that decompose lignocellulosic material are being studied as producers of enzymes to perform enzymatic hydrolysis of the lignocellulosic material present in residues from the agroindustries. Although the cellulose and hemicellulose present in these materials have their value for feeding cattle, their bioavailability requires breakdown of the bonds with indigestible lignin. Predigestion of such materials with ligninases, xylanases and pectinases (cellulase free) may transform the lignocellulosic substrate into a feed with greater digestibility and higher quality for ruminants.. This review provides an overview of variables to be considered in the utilization of fungal plantdepolymerizing enzymes produced by solid-state fermentation from agricultural production residues in Brazil. (c) 2007 Elsevier B. V. All rights reserved.

Genetic correlations between categorical morphological traits in Nelore cattle by applying Bayesian analysis under a threshold animal model

P>In this study, Bayesian analysis under a threshold animal model was used to estimate genetic correlations between morphological traits (body structure, finishing precocity and muscling) in Nelore cattle evaluated at weaning and yearling. Visual scores obtained from 7651 Nelore cattle at weaning and from 4155 animals at yearling, belonging to the Brazilian Nelore Program, were used. Genetic parameters for the morphological traits were estimated by two-trait Bayesian analysis under a threshold animal model. The genetic correlations between the morphological traits evaluated at two ages of the animal (weaning and yearling) were positive and high for body structure (0.91), finishing precocity (0.96) and muscling (0.94). These results indicate that the traits are mainly determined by the same set of genes of additive action and that direct selection at weaning will also result in genetic progress for the same traits at yearling. Thus, selection of the best genotypes during only one phase of life of the animal is suggested. However, genetic differences between morphological traits were better detected during the growth phase to yearling. Direct selection for body structure, finishing precocity and muscling at only one age, preferentially at yearling, is recommended as genetic differences between traits can be detected at this age.

An animal model for the study of Chamomilla in stress and depression: pilot study

The behavioral and hematological effects of treatment with Chamomilla 6cH in mice subjected to experimental stress are described. Swiss mice were randomly divided into pairs, one animal was inoculated with Ehrlich's tumor, the other was treated daily with Chamomilla 6cH or control or received no treatment. After 7 days, the animals were observed in an open-field arena and blood samples taken. Mice who cohabitated with a sick cage-mate showed a decrease in their general activity, but those treated with Chamomilla 6cH were less severely affected (p = 0.0426). No hematologicall changes were observed.In a second experiment, the forced swimming test was applied to mice pre-treated with Chamomilla 6cH, controls were: water, 10% ethanol or amitriptyline. Only the amitriptyline and ethanol treated groups showed significant excitatory behavior (p = 0.0020), Chamomilla 6cH treated animals' scores intermediate between water control and ethanol or amitriptyline. A decrease in the leukocyte count was observed in the amitriptyline and Chamomilla 6cH treated groups (p = 0.039). These data suggest that treatment with Chamomilla 6cH is related to the recovery of basal behavioral conditions in mice subjected to stressful conditions.

Molecular tools and analytical approaches for the characterization of farm animal genetic diversity

Genetic studies of livestock populations focus on questions of domestication, within- and among-breed diversity, breed history and adaptive variation. In this review, we describe the use of different molecular markers and methods for data analysis used to address these questions. There is a clear trend towards the use of single nucleotide polymorphisms and whole-genome sequence information, the application of Bayesian or Approximate Bayesian analysis and the use of adaptive next to neutral diversity to support decisions on conservation.

Escherichia coli phylogenetic group determination and its application in the identification of the major animal source of fecal contamination

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

Plant Cell Wall Research Related to Evolution and Chemical Defenses

The plant cell wall is composed mainly of polysaccharides some constituted of repeating units of a single sugar, as cellulose or by two or more sugars grouped in repeating oligosaccharide blocks as the galactomannans and xyloglucans. Variations in composition and fine structure of these cell wall polysaccharides have been used as taxonomic markers and in the comprehension of the evolutive process, particularly in the Leguminosae. Partial hydrolysis of these compounds give rise to oligomers, some of which are capable of eliciting the synthesis of defensive substances in plants named phytoalexins. Species which differ in respect to phytoalexin liberation also differ in cell wall composition, particularly in the pectic fraction of the wall. Pectinases (mainly endopolygalacturonases) present in fungi, have been shown to hydrolyze plant cell walls yielding phytoalexin-eliciting oligosaccharides which differ in composition and in eliciting capacity in different species. These differences can be associated with the capacity of a given species to produce phytoalexins. On the other hand, the phytoalexin induction in plants is being used as a method of producing novel bioactive secondary metabolites.

Refining the intestinal motility test in mice to reduce animal stress

A new protocol using 3-h fast animal for intestinal motility test was developed in our laboratory aiming the 3R's concept to reduce the stress of animals. Our results may aid in formulating recommendations that can be included in revised guidelines with regard to fasting time of mice.

Toxicity of hypercaloric diet and monosodium glutamate: oxidative stress and metabolic shifting in hepatic tissue.

The present study examines the effects of a hypercaloric diet on hepatic glucose metabolism of young rats, with and without monosodium glutamate (MSG) administration, and the association of these treatments with evaluating markers of oxidative stress. Male weaned Wistar rats (21 days old) from mothers fed with a hypercaloric diet or a normal diet, were divided into four groups (n=6): control (C) fed with control diet; (MSG) treated with MSG (4 mg/g) and control diet; (HD) fed with hypercaloric diet and (MSG-HD) treated with MSG and HD. Rats were sacrificed after the oral glucose tolerance test (OGTT), at 45 days of treatments. Serum was used for insulin determination. Glycogen, hexokinase(HK), glucose-6-phosphatase(G6PH), lipid hydroperoxide, superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) were determined in liver. HD rats showed hypoglycemia, hyperinsulinemia, and high hepatic glycogen, HK and decreased G6PH. MSG and MSG-HD had hyperinsulinemia, hyperglycemia, decreased HK and increased G6PH in hepatic tissue. These animals had impaired OGTT. HD, MSG and MSG-HD groups had increased lipid hydroperoxide and decreased SOD in hepatic tissue. Hypercaloric diet and monosodium glutamate administration induced alterations in metabolic rate of glucose utilization and decreased antioxidant defenses. Therefore, the hepatic glucose metabolic shifting induced by HD intake and MSG administration were associated with oxidative stress in hepatic tissue.

Princípios éticos na experimentação animal

The treatment of animals used in research or in education tests requires proper care, scientific judgment and qualified professionals to understand the needs of the animals and the special requirements of the research, tests, and educational programs. The established guidelines aim the development of knowledge necessary for the improvement of health and wellbeing of humans as well as animals to get precise and accurate results. The techniques should not be performed with inappropriate procedures that cause pain or suffering. Some principles should be considered to have an appropriate animal care and treatment.

Estimates of covariance functions for growth of Nelore cattle applying a parametric correlation structure to model within-animal correlations

A total of 20,065 weights recorded on 3016 Nelore animals were used to estimate covariance functions for growth from birth to 630 days of age, assuming a parametric correlation structure to model within-animal correlations. The model of analysis included fixed effects of contemporary groups and age of dam as quadratic covariable. Mean trends were taken into account by a cubic regression on orthogonal polynomials of animal age. Genetic effects of the animal and its dam and maternal permanent environmental effects were modelled by random regressions on Legendre polynomials of age at recording. Changes in direct permanent environmental effect variances were modelled by a polynomial variance function, together with a parametric correlation function to account for correlations between ages. Stationary and nonstationary models were used to model within-animal correlations between different ages. Residual variances were considered homogeneous or heterogeneous, with changes modelled by a step or polynomial function of age at recording. Based on Bayesian information criterion, a model with a cubic variance function combined with a nonstationary correlation function for permanent environmental effects, with 49 parameters to be estimated, fitted best. Modelling within-animal correlations through a parametric correlation structure can describe the variation pattern adequately. Moreover, the number of parameters to be estimated can be decreased substantially compared to a model fitting random regression on Legendre polynomial of age. © 2004 Elsevier B.V. All rights reserved.

Fluorescence spectroscopy for tongue carcinoma detection: Study in an animal model

Fluorescence diagnosis of malignant lesions has been showed as an attractive optical technique due especially to its real-time response and a more objective and quantitative evaluation. Even though the oral cavity allows a direct examination many lesions are diagnosed when it is already in advanced stage, compromising the patient prognosis. In this study, the fluorescence spectroscopy was used to the detection of chemically induced carcinoma at the lateral border of the tongue in a hamster model. Two excitations wavelengths in visible region were applied: 442 and 532 nm. All the spectra results were analyzed comparing with the histopathological diagnosis. The better results were achieved with the 442 nm laser excitation. The spectra from carcinoma showed new emission bands and these were used to determined different ratios for a quantitative analysis. Using the 625-645 nm fluorescence range under 442 nm excitation (A3 coefficient) the percentage of false negative was of 9.1%, however the false positive percentage was of 18.5%. The 532 nm excitation provided a better normal tissue detection compared to 442 nm excitation. The ideal clinical condition is probably the use of multiple wavelengths excitation for a broader tissue fluorescence investigation.

Evaluation of serum- and animal protein-free media for the production of infectious bronchitis virus (M41) strain in a continuous cell line

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)