Desempenho de frangos de corte alimentados com dietas contendo diferentes fontes de selênio, zinco e manganês, criados sob condições de estresse térmico

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

Adsorção de selênio em latossolos

A retenção de Se pelos colóides do solo constitui importante processo para a manutenção da sanidade ambiental. A informação sobre a adsorção de Se em solos altamente intemperizados é restrita e existem poucos padrões quantitativos disponíveis para a definição de estratégias de remediação de áreas contaminadas. Quantidades crescentes de Se (5, 10, 25, 50, 100 e 250 mg L-1), na forma de Na2SeO3, foram adicionadas a amostras de dez Latossolos brasileiros [três Latossolos Vermelho-Amarelos (LVA-1, LVA-2 e LVA-3), dois Latossolos Vermelhos (LV-1 e LV-2), um Latossolo Vermelho eutroférrico (LVef), um Latossolo Vermelho acriférrico (LVwf), dois Latossolos Amarelos (LA-1 e LA-2) e um Latossolo Amarelo acriférrico (LAwf)]. Isotermas de adsorção foram construídas e foi verificado o ajuste dos resultados experimentais aos modelos de Langmuir e de Freundlich. A equação de Langmuir ajustou melhor os resultados de adsorção de Se do que a isoterma de Freundlich. Todas as isotermas apresentaram o formato tipo-L (exponencial), com exceção daquelas obtidas para o LVA-1 e para o LVA-2, que apresentaram comportamento tipo-C (linear). Valores de adsorção máxima (Ads máx), estimada pelo modelo de Langmuir, variaram de 135 (LVA-3) a 2.245 mg kg-1 (LA-1), enquanto os coeficientes de afinidade (K L) estiveram entre 0,002 (LVA-2) e 0,326 (LVA-3). A constante de afinidade estimada pelo modelo de Freundlich (Kf) variou de 13,7 (LVA-2) a 180,1 (LAwf). A adsorção máxima de Se foi mais elevada no LVef e nos Latossolos ácricos (LAwf e LVwf), enquanto os maiores valores de Kf foram encontrados no LV-2, LVef, LVA-3 e LVwf. Não houve correlação entre os atributos dos solos e as constantes de Langmuir. Valores de Kf correlacionaram-se com os teores de argila (r = 0,42*) e com a capacidade de troca de ânions (r = 0,64*).

Selenato e selenito na produção, nutrição mineral e biofortificação com selênio em cultivares de alface

SELENATE and SELENITE on YIELD, MINERAL NUTRITION and BIOFORTIFICATION WITH SELENIUM IN LETTUCE CULTIVARSSelenium is an important antioxidant element associated with physiological processes in plants, microorganisms, animals, and humans. However, its mode of action and essentiality in plants are still disputed. In Brazil, information on Se in agricultural crops is extremely scarce, though there are indications that low levels of Se are being consumed by the population. The objective of this study was to evaluate the effect of selenate and selenite on yield, mineral nutrition and biofortification with Se of lettuce cultivars. The experiment was arranged in a completely randomized factorial design 5 x 3 x 2, with five lettuce cultivars (Maravilha de Verao, Rafaela, Great Lakes, Veneranda, and Vera), three Se concentrations (0, 10 and 20 mu mol L(-1)) and two forms of Se (selenate and selenite), with four replicates. Results indicate that selenate application is more appropriate for biofortification of lettuce cultivars, while the effect of selenite proved to be more toxic. The application of selenate results in increased S shoot concentrations, while selenite reduced P concentrations, and both Se forms decreased micronutrient concentrations. No genotypic variation among lettuce cultivars was observed for Se concentration, and little variation was observed for shoot dry matter yield and S, Mg, Mn, and Fe levels.

Selênio orgânico na alimentação de matrizes de tilápia-do-Nilo (Oreochromis niloticus)

Organic selenium in the diet of Nile tilapia (Oreochromis niloticus) broodstock. The aim of this study to test the effect of organic selenium supplementation in the diets of Nile tilapia broodstock. Growth, reproductive performance and performance of fingerlings were evaluated. Eighty adult fish were used, with average weight of 121.7 g and divided into groups of four animals (3 female and 1 male) stocked in 20 tanks with 1.5 cubic meters. The fish were fed five diets containing different levels of organic selenium (0.0, 0.25, 0.50, 0.75, and 1.0 mg kg-1 ration). In the experimental period, females from all tanks were captured and the eggs collected. The experimental design was entirely randomized, with five treatments and four replicates. To evaluate progeny performance, the fingerlings were shared in four aquariums and fed during 30 days with commercial diet (45% CP). The supplementation with organic selenium did not affect the productive performance as with the reproductive parameters of the broodstock (p > 0.05). on the other hand, the broodstock fed with 0.50 mg of organic selenium produced fingerlings that presented improved weight gain (p < 0.05) compared to fish fed the control diet.

Efeito da suplementação com selênio sobre a concentração sérica de creatina kinase em bovinos

The study, evaluated the addition of different concentrations of Se in mineral mixture affecting creatine kinase (CK) serum concentrations in cattle. 60 male, Nellore cattle, at about 12 months old, were randomly assigned to groups (15 calves/ group), Gc, G3,6, G5,4 or G6,4 (0, 3.6, 5.4, and 6.4 mg Se/bovine/day). The levels of serum CK in the cattle were not affected by neither the interaction selenium concentration x time nor the concentration of supplementation. However, CK levels increased over the experiment irrespective of dietary selenium concentration. In addition, the frequency of animals with CK levels above normal increased (p<0.10) in group G6,4. The concentrations of selenium studied here do not affect serum CK in cattle, but the daily concentration of 6.4 mg selenium is not recommended because it is possibly toxic effect.

Análise espermática de perdizes (Rhynchotus rufescens) criadas em cativeiro e suplementadas com selênio

Due to the commercial importance of the red-winged tinamou (Rhynchotus rufescens), for the past few years, the employment of reproductive biotechnologies has been attempted. Thirty animals were randomly assigned into two groups: control group (no selenium) and treatment group (supplemented with 0,2 a 0,8 mg selenium/ 1000 kg ration). Animals were allocated at the FCAV - UNESP/Jaboticabal (2007-2008). Semen collections were performed by digital manipulation and divided in pools of at least 150 μL. After the immediate evaluation of motility, vigour, concentration and morphology, an aliquot of 20 μL was diluted in 300 μL of physiologic solution in order to test acrosome and membrane integrities, which were performed by counting 200 cells for each test. Cells were evaluated as follows: 1) Intact acrosome: lilac acrosome; Non-intact acrosome: pink acrosome; 2) Live cells: non stained; Dead: stained. Data was statistically analysed using the SAS System for Windows. No differences were found between treatment and control groups for volume, motility, vigour, mean number of spermatozoa per animal, concentration, Intact acrosome, Intact membrane. The difference found on midpiece sperm defect (Se = 1,33 ± 0,53 and control = 3,78 ± 0,69, p = 0.0107) may be due to the damages caused by the selenium deficiency to the architecture of the midpiece, which compromises sperm mobility and fertilization capacity.

Determinação da toxicidade do selênio por meio de análises hematológicas em Oreochromis niloticus

Selenium (Se) is described as an essential micronutrient and participates in different biological functions, as the antioxidant defense systems maintenance and regulation. However, when in high concentrations, Se may cause toxic effects as well as hematological changes in fish. The aim of the present study was to determine the toxicity of selenium in the form of sodium selenate (Na 2Se 6+O 4) in Oreochromis niloticus based on hematological parameters, after exposure to different concentrations (0.01, 0.14 and 1.4 mg Se 6+ L -1). The erythrocytic and leukocytic series were examined over 14 days at intervals of 0, 3, 5, 7,10 and 14 days. The erythrocytic series showed significant alterations in the first 7 days, including the control group. Neutrophils and monocytes showed variations in the first 3 days at a concentration of 1.40 mgSe 6+ L -1 characterizing an acute response. The total number of leukocytes was different in relation to time zero on all Se concentrations. The thrombocyte count also differed statistically from time zero and control in the first 3 days at 0.14 mgSe 6+ L -1. These results indicate that different concentrations induce an acute response with diminution of total leukocytes, neutrophilia, monocytosis and thrombocytosis.

Suplementação com selênio orgânico nas dietas de tilápia do Nilo (Oreochromis niloticus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Suplementação de selênio orgânico em dietas de reprodutores de tilápia-do-Nilo (Oreochromis niloticus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atividade do micronutriente selênio na cinética de proliferação celular, citotoxicidade, indução de apoptose e expressão dos genes CASP9, BCL-XL e APC em células HT29

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Suplementação dietética de selênio e vitamina E: variáveis fisiológicas e desempenho de juvenis de pacu (Piaractus mesopotamicus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Adsorsão e coeficientes de distribuição de selênio em solos do Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estado nutricional e perfil bioquímico de zinco e selênio em pacientes com deficiência de UgA

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação hematológica, bioquimica e hormonal em equinos submetidos à atividade de policiamento sob influência da suplementação de vitamina E, selênio e cromo

Pós-graduação em Medicina Veterinária - FMVZ

Suplementação de ração de codornas com selênio, zinco e manganês de fonte orgânica

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