Effect of starch-based supplementation level combined with oil on intake, performance, and methane emissions of growing Nellore bulls on pasture.

Intake of tropical grass forages alone is generally insufficient to avoid nutrition imbalances and reduced animal performance; therefore, supplementation is often recommended. The hypothesis of the present study is that when combined with fat, soybean hulls (SH) could replace corn as a source of energy, reducing methane production without affecting animal performance. This study evaluated the effects of starch-based supplementation level combined with oil on intake, digestibility, performance, and methane emissions of growing Nellore bulls (P = 44; initial BW = 250.69 ± 27 kg) fed cv. Xaraés during the rainy season. There were no interactions between starch level and oil supplementation with regard to intake of DM (P = 0.67), forage DM (P = 0.55), supplement DM (P = 0.14), OM (P = 0.66), CP (P = 0.74), NDF (P = 0.50), ether extract (EE; = 0.47), and GE ( P= 0.68). The intake of EE was greater for animals supplemented with oil than those fed supplements without oil (P < 0.01). There were no interactions between starch level and oil supplementation on digestibility of DM (P= 0.18), OM (P = 0.11), NDF (P= 0.42), and EE (P = 0.14). Moreover, there was interaction between starch and oil supplementation on GE (P < 0.01). Independent of starch level used, the addition of oil decreased the digestibility of OM (P = 0.04) and NDF (P = 0.03). There were no main effects of starch level, oil, or interaction between starch and oil for initial BW (P = 0.10), final BW (P = 0.94), ADG (P = 0.40), feed efficiency (P= 0.37), and carcass gain (P = 0.38). There was no interaction between starch-based supplementation level and oil on methane emissions when expressed in grams per day (P = 0.77), kilograms per year (P = 0.77), grams per kilogram DMI (P = 0.53), and grams per kilogram carcass gain (P= 0.31). There was, however, an interaction (P = 0.04) between starch level and oil on methane emissions when corrected for NDF intake. Additionally, oil decreased enteric methane emission for intake of GE (P = 0.04) and EE (P < 0.01) of animals fed with starch level. Soybean hulls have an estimated feeding value similar to that of corn. The use of oil supplementation may be effective to reduce enteric methane emission of Nellore bulls raised on pasture.

Spatial cognitive deficits in an animal model of Wernicke-Korsakoff syndrome are related to changes in thalamic VDAC protein concentrations.

Proteomic profiles of the thalamus and the correlation between the rats' performance on a spatial learning task and differential protein expression were assessed in the thiamine deficiency (TD) rat model of Wernicke-Korsakoff syndrome. Two-dimensional gel-electrophoresis detected 320 spots and a significant increase or decrease in seven proteins. Four proteins were correlated to rat behavioral performance in the Morris Water Maze. One of the four proteins was identified by mass spectrometry as Voltage-Dependent Anion Channels (VDACs). The association of VDAC is evident in trials in which the rats' performance was worst, in which the VDAC protein was reduced, as confirmed by Western blot. No difference was observed on the mRNA of Vdac genes, indicating that the decreased VDAC expression may be related to a post-transcriptional process. The results show that TD neurodegeneration involves changes in thalamic proteins and suggest that VDAC protein activity might play an important role in an initial stage of the spatial learning process.

Fatty acid profile, carcass and quality traits of meat from Nellore young bulls on pasture supplemented with crude glycerin.

The aim of this study was to evaluate the carcass traits and meat quality of Nellore bulls (279.5±16.3 initial body weight) raised on pasture supplemented with crude glycerin at 0%, 7%, 14%, 21% or 28% (DM basis). The diets were similar in energy and protein levels, and the glycerin replaced corn in the supplement. After slaughter, the carcass characteristics were measured, and the longissimus muscle was collected to determine the meat quality. The inclusion of crude glycerin in the supplement did not change (P>0.05) any of the carcass characteristics and meat quality assessed; however, the pH decreased linearly (P=0.03), and margaric acid (17:0) increased (P=0.02) in the longissimus muscle with the addition of glycerin in the diet. Our conclusion is that the inclusion of crude glycerin up to the level of 28% of dry matter in the supplement does not alter the carcass characteristics or the meat quality from animals raised on pasture.

Perfil bioquímico sanguíneo na intoxicação experimental com extrato de Mascagnia rigida (A. Juss.) Griseb. (Malpighiaceae) em coelhos / Biochemistry profile after experimental intoxication by extract of Mascagnia rigida (A. Juss.) Griseb. (Malpighiaceae) in rabbits

Avaliou-se o perfil bioquímico sanguíneo na intoxicação por Mascagnia rigida, uma planta tóxica que gera problema econômico para a pecuária, por causar morte súbita. Nove coelhos Nova Zelândia, machos, com massa corporal média de 3,54kg, foram distribuídos em três grupos (G) (n=3). Os animais receberam, durante oito dias consecutivos, o equivalente a 30g/kg de matéria seca da planta em dois tipos de extratos: solúvel em água (GS) e insolúvel em água (GI), e formou-se também o grupo-controle (GC). Os exames bioquímicos foram realizados previamente ao início do experimento até o nono dia. A administração dos extratos da Mascagnia rigida causou alterações eletrolíticas que podem justificar alguns sinais clínicos observados e atuar de forma significativa na causa mortis.

A study was carried out to evaluate the biochemical profile in Mascagnia rigida poisoning, a toxic plant that generates a significant economic problem to livestock, causing "sudden death". Nine New Zealand rabbits, male, 3,54kg mean body weight were divided into three groups (G) (n = 3). The animals received the equivalent of 30g/kg of dry matter in two types of extracts: water-soluble (GS) and insoluble in water (GI), and the control group (CG) (ultra-pure water) for eight consecutive days. Biochemical exams were done prior to the beginning of the experiment until the ninth day. It was concluded that the administration of extracts of Mascagnia rigida cause electrolyte imbalances that may justify some clinical signs and act significantly in the cause of death.

Assessment of antimutagenic and genotoxic potential of senna (Cassia angustifolia Vahl.) aqueous extract using in vitro assays.

Senna (Cassia angustifolia Vahl.) is widely used as a laxative, although potential side effects, such as toxicity and genotoxicity, have been reported. This study evaluated genotoxic and mutagenic effects of senna aqueous extract (SAE) by means of four experimental assays: inactivation of Escherichia coli cultures; bacterial growth inhibition; reverse mutation test (Mutoxitest) and DNA strand break analysis in plasmid DNA. Our results demonstrated that SAE produces single and double strand breaks in plasmid DNA in a cell free system. On the other hand, SAE was not cytotoxic or mutagenic to Escherichia coli strains tested. In effect, SAE was able to avoid H(2)O(2)-induced mutagenesis and toxicity in Escherichia coli IC203 (uvrA oxyR) and IC205 (uvrA mutM) strains, pointing to a new antioxidant/antimutagenic action of SAE.

Dual targeting properties of the N-terminal signal sequence of Arabidopsis thaliana THI1 protein to mitochondria and chloroplasts.

thi1 has been recently isolated from Arabidopsis thaliana and is probably involved in both thiamine biosynthesis and as protection of organellar DNA from damage. Studies of thiamine biosynthesis in plants suggests a plastid location for the pathway, which is in agreement with the predicted THI1 N-terminal chloroplastic transit peptide (TP). On the other hand, thiamine is synthesized in mitochondria in yeast cells. Interestingly, A. thaliana thi1 cDNA complements a yeast strain disrupted for the homologous gene. Analysis of THI1 amino acid sequence revealed the presence of a putative amphiphilic alpha-helix, which is typical for mitochondrial presequences, located downstream of the chloroplast transit peptide. To define the putative role of the two predicted targeting sequences in tandem, we produced two chimeric genes encompassing the chloroplastic THI1 TP and either 4 or 27 (including the putative mitochondrial presequence) N-terminal residues of the mature THI1, both linked to the reporter (gusA) gene. Analysis of GUS distribution in subcellular fractions of transgenic plants revealed that in the construct retaining only 4 residues of mature THI1, GUS was found in the chloroplastic fraction. Extension of the THI1 transit peptide to 27 residues of the mature protein allowed import and processing of GUS into both mitochondria and chloroplasts. Direct analysis by immunogold-labeling with an anti-THI1 polyclonal antibody identified THI1 in both organelles in Arabidopsis. We also provide evidence that the precursors of both organellar isoforms are encoded by a single nuclear transcript. Thus, THI1 is targeted simultaneously to mitochondria and chloroplasts by a post transcriptional mechanism.

[Effect of denervation on macromolecular metabolism in electric tissue of Electrophorus electricus (L)]. / Effet de la dénervation sur le métabolisme macromoléculaire chez le tissu électrique de l'Electrophorus electricus (L)

Unilateral denervation of the principal electric organ of the Electrophorus electricus produces in the denervated an increase of its content of RNA. This increase results, as shown by radioactive incorporation, from an increase in RNA synthesis and is followed by an increase in aminoacid incorporation by proteins. Protein concentration does not change significantly, implying that a change of the proteic pattern occurs. The increase in the RNA content follows denervation rather rapidly but comes down to approximately 10% of the initial value sixty days afterwards.