Evaluation of in vitro gas production of roughages and their mixtures using the curves subtraction method

The in vitro gas production of four single roughages and their paired combinations (1:1 on dry matter basis) were evaluated. Two roughage samples (100 mg) per treatment were fermented with ruminal fluid during a 48 h incubation period. Total 48 h gas volumes of fermentation dry matter (DM), neutral detergent fiber (NDF) and soluble compounds in neutral detergent (NDS) were for sugarcane = 16.8, 11.2, 6.9 mL; sugarcane + corn silage = 20.1, 12.6, 9.1 mL; sugarcane + 60-day elephantgrass = 16.5, 17.6 mL; sugarcane + 180-day elephantgrass = 13.8, 8.2, 5.9 mL; corn silage = 18.8, 16.8, 4.7 mL; corn silage + 60-day elephantgrass = 16.3, 15.4, 2.4 mL; corn silage + 180-day elephantgrass = 16.1, 11.8, 4.2 mL; 60-day elephantgrass = 16.9, 19.0 mL and 180-day elephantgrass = fermented 10.7, 12.2 mL, respectively. The NDS gas production was not possible to estimate for sugarcane + 60-day elephantgrass, 60-day elephantgrass and 180-day elephantgrass. The present data shows that the curves subtraction method can be an option to evaluate the contribution of the soluble fractions in roughages to digestion kinetics. However, this method underestimates the NDS gas contribution when roughages are low in crude protein and soluble carbohydrates. It is advisable to directly apply the two-compartmental mathematical model to the digestion curves for roughage DM, when determining the NDS gas volume and the digestion rate. This method is more straightforward and accurate when compared to the curve subtraction method. Non-structural carbohydrates combined with fiber and protein promoted a positive associative effect in sugarcane + corn silage (50:50) mixture. Therefore, it can be concluded that the soluble fraction of roughages greatly contributes to gas production. (C) 2004 Elsevier B.V. All rights reserved.

Seed dispersal by fishes in tropical and temperate fresh waters: The growing evidence

Fruit-eating by fishes represents an ancient (perhaps Paleozoic) interaction increasingly regarded as important for seed dispersal (ichthyochory) in tropical and temperate ecosystems. Most of the more than 275 known frugivorous species belong to the mainly Neotropical Characiformes (pacus, piranhas) and Siluriformes (catfishes), but cypriniforms (carps, minnows) are more important in the Holarctic and Indomalayan regions. Frugivores are among the most abundant fishes in Neotropical floodplains where they eat the fruits of a wide variety of trees and shrubs. By consuming fruits, fishes gain access to rich sources of carbohydrates, lipids and proteins and act as either seed predators or seed dispersers. With their often high mobility, large size, and great longevity, fruit-eating fishes can play important roles as seed dispersers and exert strong influences on local plant-recruitment dynamics and regional biodiversity. Recent feeding experiments focused on seed traits after gut passage support the idea that fishes are major seed dispersers in floodplain and riparian forests. Overfishing, damming, deforestation and logging potentially diminish ichthyochory and require immediate attention to ameliorate their effects. Much exciting work remains in terms of fish and plant adaptations to ichthyochory, dispersal regimes involving fishes in different ecosystems, and increased use of nondestructive methods such as stomach lavage, stable isotopes, genetic analyses and radio transmitters to determine fish diets and movements. (C) 2011 Elsevier Masson SAS. All rights reserved.

Fibre analysis and fibre digestibility in pet foods - a comparison of total dietary fibre, neutral and acid detergent fibre and crude fibre

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

Análise físico-química e composição nutricional da matéria prima e de substratos pré e pós cultivo de Pleurotus ostreatus

The aim of the present study was to carry out the physical, chemical and nutritional analyses of the alternative substrates formulated from wood and agroindustrial residues of the Amazon for Pleurotus ostreatus (Jacq.:Fr.) Kummer cultivation. The determination of C, N, pH, humidity, soluble solids, protein, fat, total fiber ash, carbohydrates (total and available) and energy were carried out. The substrates were formulated from sawdust of Simarouba amara Aubl. (marupa), Ochroma piramidale Cav. ex. Lam. (pau de balsa) and from the stein of Bactris gasipaes Kunth (pupunheira palm tree), and from Saccharum officinarum L. (sugar cane bagasse). The results demonstrated that the nutritional composition of the substrate is variable and the improvement of the quality of the spent substrate (energy and protein increment) promoted by the metabolism of the fungus during the cultivation, contributed for a more nutritive substrate than the initial one, which could be used as a compost for Agaricus sp. cultivation, as organic fertilizer and for bioremediation for contaminated soils.

Control of lipase production by Rhizopus oligosporus under various growth conditions

Some factors influencing the growth and production of extracellular lipase by Rhizopus oligosporus were studied. Highest yields of enzyme were obtained when Tweens were the carbon source. Soybean meal extract supported good growth and enzyme production. Carbohydrates, vegetable oils, proteins or amino acids did not stimulate lipase production. The fungus grew well with carbohydrate- or protein-supplemented media but not with oils, unless emulsified with a non-metabolizable gum. The production of biomass in static cultures was maximum at 35-40°C after 4 d at pH 5.5. The yield of lipase was maximum at 25°C after 3 d at pH 6.5. Shaking cultures enhanced growth but decreased lipase production.

Soluble phosphate accumulation by Aspergillus niger from fluorapatite

In order to determine conditions that may provide greater solubilization of insouluble phosphate, the fungus Aspergillus niger was grown in a stationary culture containing modified citrate medium supplemented with 800 mg fluorapatite per litre. Solubilization of insouluble phosphate increased with fungal growth, reaching a maximum after 11 days of culture. Soluble phosphate levels were correlated with pH of the culture medium but not with titratable acidity values, probably due to the metabolic activity of the fungus resulting from consumption of sugar in the culture medium. Fructose, glucose, xylose, and sucrose were the carbohydrates that favoured fluorapatite solubilization the most when compared with galactose and maltose. Although increasing fructose concentrations in the culture medium favoured mycelial growth, increased total acidity and a fall in pH, soluble phosphate levels were reduced, probably owing to consumption by the rapidly growing fungus. Among the nitrogen sources tested, ammonium salts favoured the production of larger amounts of soluble phosphate than organic nitrogen (peptone or urea) or nitrate, corresponding to the lowest pH and highest titratable acidity values obtained. © 1988 Springer-Verlag.

Características histoquímicas e estruturais do testículo do morcego hematófago (Desmodus rotundus rotundus, Geoffrey, 1810).

The testicular stroma of the vampire bat including the testicular capsula and the lamina propria of the seminiferous tubuli, was strongly PAS-positive. This observation was a possible indication of great amounts of structural glycogen and other glycoconjugates at the level of smooth muscle cells; elongated contractile cells and/or collagen frameworks of the tunica albuginea and tubular lamina propria. In the last the basement membranes of the seminiferous tubules were particularly strongly PAS positive, as an indication of their neutral mucosubstances structural composition, previously described (Malmi et al., 1987). The epithelium lining from the cavitary and surface rete testis complex showed low reactivities to mucosubstances; total proteins and lipids and oxidative enzymes studied. Although the apical granulation at the rete testis epithelium showed an intense PAS reactivity with hypothesis of glycoprotein secretion, through the rete. The PAS, Sudan Black B, NADH, MDH and LDH reactions of the testicular interstitium seem correlate to steroid metabolism (biosynthesis and secretion), at the Leydig cells level. The seminiferous epithelium generally had low reactions to all the histochemical studies realized. Particularly in the adbasal compartment the histochemical localizations of NADH diaphorase and LDH were possible related to glycolytic activities and general carbohydrates metabolism, both enzymes, and hydrogen transport, the NADH. The strong PAS, diastase and PAS, and alcian blue pH 2.5 and PAS reactions observed in the adluminal seminiferous epithelium compartment were directly related to the spermatids acrosomal glycoconjugates structuration. Also the SDH localization at this level seems to be related to the mitochondrial activities at the middle piece level in the late spermatids.

Increased oxygen radical and high-dietary-carbohydrate pancreatic damage.

These data suggest that an improved understanding of the relationship between high dietary carbohydrate and the rate of lipid peroxidation may give some insight into possible treatment modalities for pancreatic damages and may shed light on molecular mechanisms underlying certain pathological processes. High dietary carbohydrate lesions are age related and induced alterations on ceruloplasmin, phospholipids, total proteins, copper and zinc serum levels. Significantly increased serum and pancreatic amylase, and lipoperoxide determinations were observed in 20 month old rats. Cu-Zn superoxide dismutase was decreased in these animals. Daily injection of Cu-Zn superoxide dismutase conjugated with polyethylene glycol (SOD-PEG) prevented the serum and pancreatic changes, indicating that superoxide radical is an important intermediate to high dietary carbohydrate lesion.

Metabolic adaptations induced by long-term fasting in quails

After up to 21 days without food, adult male quails (Coturnix coturnix japonica) lost about 45% of the initial body weight (100-150 g). As in naturally fast-adapted and larger birds, three phases were identified during prolonged fasting in quails. Phase I lasted 2-3 days and was characterized by a rapid decrease in the rate of body weight loss and high fat mobilization. Phase II was longer and characterized by a slow and steady decline in the rates of body weight loss and of nitrogen excretion. The third (critical) period was marked by an abrupt increase in the rates of body weight loss and of nitrogen excretion. Despite their small size, the duration of phase II in quails was relatively long, a clear advantage for the study of the relationships between the several metabolic events that occur during this crucial adaptative period. Also, the beginning of phase III could be precisely determined. Changes in blood glucose, plasma FFA and triacylglycerols levels, as well as in liver and carcass lipid content were similar to those found in other species of birds. Therefore, quails seem to be a suitable model to investigate the biochemical mechanisms involved in the metabolic adjustments to prolonged food deprivation in non fasting-adapted birds. © 1995.

Immunochemical study of a Paracoccidioides brasiliensis polysaccharide-like antigen

The polysaccharide antigen from P. brasiliensis has been largely employed in serologic tests, as well as in skin tests, to evaluate cellular immunity. SDS-PAGE analysis of this antigen has revealed a variability in the number of bands exhibited by isolates SN, 265, 339, 113 and 18 (7 to 16 bands). The antigens obtained from isolates 2, PTL, 192 and Adel showed two or three bands. Glycoprotein analysis demonstrated a broad region between 50 and 90 kDa. Major bands of 48 and 30 kDa were present in almost all antigens. Optimal complement fixing dilution appears to be unaffected by the number of bands presented by different antigens. The immunoblot analysis revealed that the 90 and 30 kDa bands were mainly recognized by sera from paracoccidioidomycosis patients. Bands of high molecular weight were also recognized by most of the sera studied. Sera from histoplasmosis recognized the 94 kDa band. In conclusion, although the isolates exhibit quantitative variability in the number of fractions, it is possible to use only one or two samples given the greatest frequency of reactivity is seen in the 30 and 90 kDa fractions.

Avaliação do triticale (X triticosecale wittimack) para silagem

Silages from three cultivars of triticale (X Triticosecale wittimack) were evaluated at the UNESP, Jaboticabal, Brazil. The cultivars FCA VJ-CB-01, FCA VJ-CB-02, and FCA VJ-CB-03 were harvested for silage in three growing stages of maturity; beginning of flowering, (S1), milk stage (S2), and dough stages (S3). Data were analyzed by randomized complete block with three replications. The DM (%) values increased while the CP (%DM) and buffering capacity (me HCl/100 g DM) decreased with plant development. Silages of plants harvested at S3 stage had higher pH and N-NH3 values compared to the S1 and S2 silages. The soluble carbohydrates contents (%DM) were higher at the S2 stage (16.9%) and were not different at the S1 (8.7%) and S3 (9.2%) stages. The crude energy contents (Kcal/kg MS) increased while the ADF, NDF, cellulose, and hemicellulose (DM%) decreased due to the presence of dough grains. This was not observed with the lignin contents. The IVDMD values were 66.3, 60.1 and 58.9%, for plants harvested at the S1, S2, and S3 stages, respectively. The results showed that there was no difference among for chemical composition, crude energy, and for IVDMD.

Avaliação da silagem de grãos úmidos de milho

This work had the objective of evaluating the effects of different percentages of corn (Zea mays L.) cob on the quality of the silage of high-moisture corn grains. The following treatments were studied: percentages of corn cob in the silage (0, 5, 10, 15 and 20%); period of sampling after opening the silos (zero, two, four and six days). The factorial arrangement 5 × 4 was studied according to a completely randomized block design with three replications. The variables studied were not affected by the sampling period. The buffering capacity and the pH were not affected by the cob, while the percent soluble carbohydrates and amoniacal nitrogen increasing until 1.2 and 1.89 unit percent, respectively. Increasing the amount of corn cobs reduced the contents of DM (from 63.9% to 58.6%), CP (from 10.0% to 7.3%), EE (from 4.87% to 3.92%) and the values of DMIVD (from 90.5% to 79.1%) in the silages and increasing the contents of acid detergente fiber (ADF) (from 3.3% to 12.9%) and neutral detergente fiber (NDF) (from 15.16% to 26.1%). The values of brute energy (BE) were not affected (P>0.01) by the cob corn in the silage.

Aditivos na ensilagem do capim-elefante. I. Composição bromatológica das forragens e das respectivas silagens

The effect of the addition of ground ear corn with husks, wheat bran and saccharin, on the rate of 0, 8, 16 and 24% (dry weight of additive/wet weight of cut green grass), upon the chemical composition of both fodder and silage of Pennisetum purpureum Schum. cv. Guaçu was evaluated. A split-plot randomized block design was used. The plots were the additives and their levels and the sub-plots the material types (forage + additives and their silages). The grass was fertilized with 20 t/ha of green manure and 80, 160 and 160 kg/ha of P2O5, N and K2O, respectively. The material (chopped grass mixed with the levels of the additives) was ensiled in experimental silos (200 L plastic vessels). The dry matter percentages increased linearly as additive levels increased, being greater the effect of ground ear corn with husks. Wheat bran addition and saccharin increased the crude protein and soluble carbohydrates percentages while the ground ear corn with husks addition decreased them. Losses of dry matter soluble compounds (CP, ash and NFE) and a relative rise in the less soluble compounds (CF and organic matter) were observed.

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.