Ultrastructural aspects of the mandibular gland of Melipona bicolor Lepeletier, 1836 (Hymenoptera : Apidae, Meliponini) in the castes

The mandibular gland in Melipona bicolor workers and queens was studied by scanning and transmission electron microscopy. There is no difference in the gland anatomy between the castes, but the transmission electron microscopy showed variation of the cellular ultrastructure according to the secretory phase of the gland in both castes. Smooth endoplasmic reticulum was abundant in the secretory cells of physogastric queens, indicating that these cells produce lipid secretion that is stored in granules with multi-lamellar bodies. Mitochondrial variations during the cell secretory cycle indicates their participation in the lipid synthesis. After secretion, release in the reservoir lumen through the collecting canals, the secretory cells contain many myelinic bodies, indicative of cellular regression. (C) 2004 Elsevier Ltd. All rights reserved.

Oxalate determination in urine using an immobilized enzyme on Sorghum vulgare seeds in a flow injection conductimetric system

A flow-injection (FI) method was developed for the determination of oxalate in urine. It was based on the use of oxalate oxidase (E.C. 1.2.3.4) immobilized on ground seeds of the BR-303 Sorghum vulgare variety. A reactor was filled with this activated material, and the samples (200 μL) containing oxalate were passed through it, carried by a deionized water flow. The carbon dioxide produced by the enzyme reaction permeated through a microporous PTFE membrane, and was received in a water acceptor stream, promoting conductivity changes proportional to the oxalate concentration in the sample. The results obtained showed a useful linear range from 0.05 to 0.50 mmol dm-3. The proposed method, when compared with the Sigma enzymatic procedure, showed good correlation (Y = 0.006(±0.016) + 0.98(±0.019)X; r = 0.9995, Y = conductivity in μS, and X = concentration in mmol dm-3), selectivity, and sensitivity. The new immobilization approach promotes greater stability, allowing oxalate determination for 6 months. About 13 determinations can be performed per hour. The precision of the proposed method is about ± 3.2 % (r.s.d).

The chemical composition of the mandibular gland secretion of Melipona bicolor lepeletier, 1836 (Hymenoptera, Apidae, Meliponini): A comparative study among castes and sexes

The mandibular gland secretions of newly emerged, nurse and forager workers, virgin and physogastric queens and males of Melipona bicolor were analyzed by gas chromatography-mass spectrometry. The secretion is composed of a blend of hydrocarbons, alcohols, esters, and acids. The secretion is caste-sex specific and also differs with the tasks performed by the workers and the physiological reproductive condition of the queens.

Effects of corn replacement by sorghum in broiler diets on performance and intestinal mucosa integrity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Demanda energética de sistemas de manejo do solo na cultura da soja (Glycine max L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção e composição do leite de ovelhas da raça bergamácia suplementadas com óleo de linhaça (Linum usitatissimum L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morfoanatomia e ontogênese de frutos e sementes de três espécies de Chamaecrista moench (Fabaceae, Caesalpinioideae) de cerrado do Estado de São Paulo

Pós-graduação em Ciências Biológicas (Botânica) - IBB

Efeito de adubação orgânica e mineral e culturas de entressafra na cultura da soja (Glycine max (L) Merrill) no sistema plantio direto

Pós-graduação em Agronomia - FEIS

Implications of the use of sorghum in broiler production

This study aimed at evaluating total or partial replacement of corn by sorghum in broiler diets and at estimating the effect of the pigment supplementation on broiler performance, carcass and cuts yield, and possible breast and leg pigmentation. We used 1680 one-d-old Ross® 308 broilers. Birds were sexed and distributed according to a completely randomized design (2 x 3 + 1). Treatments consisted of a control diet based on corn and diets with two levels corn replacement by sorghum (50 and 100%) and three pigments levels, with four replicates of 60 birds per treatment. There was no effect (p > 0.05) of the dietary replacement of corn by sorghum on performance, carcass and parts yield, and no changes in breast and leg meat pH (p >0.05). Meat redness (a*), yellowness (b*) and luminosity (L*) increased (p < 0.05) as pigment inclusion levels increased. It was concluded that the use of sorghum instead of corn did not affect broiler performance or carcass and cuts yield. When adequate pigments were used, meat color significantly improved.

Analysis of the intestinal bacterial microbiota in maize- or sorghum-fed broiler chickens using real-time PCR

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of the particle size of maize, rice, and sorghum in extruded diets for dogs on starch gelatinization, digestibility, and the fecal concentration of fermentation products

The influence of rice, maize, and sorghum raw material particle size in extruded dry dog food on the digestibility of nutrients and energy and the fecal concentration of fermentation products was investigated. Three diets with similar nutrient compositions were formulated, each with 1 starch source. Before incorporation into diets, the cereals were ground into 3 different particle sizes (approximately 300, 450, and 600 mu m); therefore, a total of 9 diets were in a 3 x 3 factorial arrangement (3 cereals and 3 particle sizes). Fifty-four beagle dogs (12.0 +/- 0.1 kg BW) were randomly assigned to the diets, with 6 dogs per diet. The digestibility was measured with the chromium oxide method. The data were evaluated with ANOVA considering the carbohydrate source, grinding effect, and interactions. The means were compared with the Tukey test and polynomial contrasts (P &lt; 0.05). With the same grinding procedure, rice was reduced to smaller particles than other cereals. The cereal mean geometric diameter (MGD) was directly related to starch gelatini-zation (SG) during extrusion. For rice diets, the MGD and SG did not change nutrient digestibility (P &gt; 0.05); only GE digestibility was reduced at the largest MGD (P &lt; 0.01). For maize and sorghum diets, the total tract apparent nutrient digestibility was reduced for foods with greater MGD and less SG (P &lt; 0.01). A linear reduction in nutrient digestibility according to cereal particle size was observed for sorghum (r(2) &lt; 0.72; P &lt; 0.01). Higher concentrations of fecal total shortchain fatty acids (SCFA) were observed for sorghum diets (P &lt; 0.05) than for other diets. The rice diets led to the production of feces with less lactate (P &lt; 0.05). The increase in raw material MGD did not influence fecal SCFA for rice diets, but for the dogs fed maize and sorghum foods, an increase in propionate and butyrate concentrations were observed as MGD increased (P &lt; 0.05). In conclusion, for dogs fed different particle sizes of the cereal starches in the extruded diets, the digestibility and fecal characteristics were affected, and this effect was ingredient dependent.