Estabilidade da fitase e sua utilização na alimentação de frangos de corte

This work was designed to evaluate the effect of storage forms and conditions upon the enzyme activity of phytase and bioavaibility of calcium and phosphorus in broiler diets. The work was accomplished in two steps. The first step, made in the laboratory measured the activity of the phytase enzyme along the storage period. In this step, two experiments were performed: Experiment 1, constituted of 5 treatments (pure phytase stored at 0 °C, 4 °C and environmental temperature and mixed to vitamin and mineral supplement, stored at environmental temperature) in CRD and split plot scheme. The activities were evaluated every 14 days for 112 days of storage, being verified that the phytase storage in the pure form at 0o C was superior to the other treatments. Experiment 2, made up of 4 treatments (phytase mixed to the ration directly, directly and afterwards pelleted, via mineral supplement and via vitamin supplement),all the treatments being stored at environmental temperature, in CRD and split plot scheme. The activities were evaluated every 7 days for 56 days' storage, being verified that the storage of the phytase mixed to the ration via vitamin supplement and directly with the ration pelleted later, provoked a fall in phytase activity when compared with the other treatments. In the second step, the effect of phytase on the bioavaibility of calcium and phytic phosphorus was evaluated, 2 experiments being accomplished (3 and 4); in both experiments were utilized 576 broiler line chicks, housed in an array of heated batteries, receiving practical diets on the basis of corn and soybean meal (basal) for 21days. At the end of 27 days of age,96 birds were slaughtered for evaluation of the mineral contents (Ca and P) in the tíbias and plasma phosphorus. The excretae were collected from 22 to 27 days of age of the birds. Experiment 3: A CRD with the treatments in 2 x 3 x 2 +4 factorial arrangement was utilized, namely, two levels of total phosphorus (0.35 and 0.45% of total phosphorus), three leveis of phytase (500, 750 and 1,000 FTU) and four additional treatments with levels of 0.35 and 0.45 % of available phosphorus for each sex, with three replicates per treatment. There was significant interaction among levels of phosphorus and phytase (P< 0.05) for weight gain, ration consumption and feed conversion. Phytase did not indicate significant differences when the level 0.45% was utilized, nevertheless, at the level 0.35% as phytase was supplemented, weight gain, ration consumption and feed conversion were improved, chiefly with 1,000 FTU/Kg, in both sexes. The males presented greater weight gain. The ration consumption and feed conversion were equal to those of females. The contrast 0.45% did not affect the performance of males and females, the same not occurring with the level 0.35%,at which the available phosphorus was superior in both the sexes. The highest contents of ashes, phosphorus and calcium in the tíbias and plasma phosphorus were obtained with the levels of 750 and 1,000 FTU/Kg of phytase and 0.45% of total phosphorus. The males presented higher contents of ashes in the tibias. The level 0.45% of available phosphorus presented the greatest contents of ashes, calcium and phosphorus in the tibias, and phosphorus in the plasma. The lowest excretions of phosphorus occurred at the levels 0.35% of total phosphorus and 1,000FTU/kg of phytase. The lowest contents of ashes and calcium in the excretae were obtained with 0.35% and 1,000FTU/Kg of phytase. The females excreted smallest amounts of ashes, calcium and phosphorus than the males. Experiment 4: a CRD with the treatments in 3 x 4 x 2 factorial arrangement, namely, three levels of phytase (0, 500 and 1,000 FTU), four levels of calcium (0.7, 0.8, 0.9 and 1.0%) with four replicates per treatment. The performance was not affected by the treatments utilized, the males being superior to the females in weight gain, feed consumption and conversion. The contents of ashes in the tibias were not affected by the levels of phytase but as calcium levels raised, the ash contents increased. The contents of calcium and phosphorus in the tibias increased with the supplementation of 500 and 1,000 FTU/kg of phytase and with calcium levels. The utilization of phytase did not decrease the excretion of ashes, calcium and phosphorus.

Eficiência agronômica da ureia estabilizada com inibidores de urease e nitrificação na cultura do milho

Nitrogen (N) is the most required nutrient for corn plants and, in order to supply this demand in highly productive crops, mineral fertilizers are used, especially urea. The disadvantage of urea is the loss of N-NH3 to atmosphere. To reverse this situation, some technologies have been developed, such as nitrification and urease inhibitors, which are used as additives to urea. This work aimed at evaluating the agronomic efficiency of urea stabilized with urease and nitrification inhibitors applied to cover the 2013/2014 corn crop. We evaluated 11 nitrogen fertilizer applied in coverage: urea + PA (41.6% N, 3% Cu); urea + PA (41.6% N, 1.5% Cu); urea + PA (41.6% N, 3% Zn); urea + PA (41.6% N, 1.5% Zn); urea + PA (41.6% N, 0.34% Cu, 0.94% B); urea + PA (41.6% N, 0.25% Cu, 0.68% B); urea + PA (41.6% N); urea (44.3% N, 0.15% Cu, 0.4% B); urea (43% N, 0.1% Cu, 0.3% B, 0.05% Mo); pearled urea (46% N); urea + 0,8% DMPP (45% N) and the control, which did not receive nitrogen topdressing. The evaluations were: Nitrogen losses through volatilization, content and accumulation of N, boron (B), copper (Cu) and zinc (Zn) to the dry matter of aerial parts, grains, and in straw and grain productivity. Fertilizers stabilized with urease and nitrification inhibitors did not reduce the volatilization of ammonia volatilization, when compared to pearled urea. Urea with 0.8% of DMPP nitrification inhibitor (3,4-dimethylpyrazole phosphate) provided higher loss by volatilization, lower productivity and agronomic efficiency compared to pearled urea. The coating of urea with Cu, B and Zn did not increase the accumulation of these nutrients in grains and MSPA plants. The use of fertilizers stabilized and coated with micronutrients did not increase the productivity and agronomic efficiency compared to conventional urea.

Caracterização mineralógica, química e solubilização do potássio de glauconita modificada

Demand for potassium in Brazil is large and is constantly increasing, but only about 5% of all consumed potassium is produced in the country. This low domestic production implies high rate of potassium imports, leaving the country vulnerable in the event of any difficulty to import this product and currency fluctuations. The modified glauconite is a rock that has a high potential for potassium exploration, found in Minas Gerais state, its extraction is relatively cheap and the prospected rock volume is high. The difficulty for its use as a direct source of potassium is in its low solubility. Thus, the objective of this study was to perform a chemical and mineralogical characterization of the modified glauconite and evaluate the effectiveness of techniques and treatments in the potassium solubilization contained in the rock. For this study, it was used characterization techniques such as X-ray diffraction, scanning electron microscopy, diffraction by Synchrotron Light and chemical analysis of high and low power of potassium extraction. Also granulometric testing and thermal treatments with different forms of calcination were carried out. Overall, it was found that the modified glauconite is a compound of minerals, of the mica groups K-feldspar and quartz and calcination substantially alter the crystal structure of these minerals, increasing the potassium availability. While the natural solubility of glauconite modified be very low, rock calcination added with high fluxes of calcium and low magnesium content at 1200 °C led to potassium solubility increase in order of 100 times compared to that observed in the glauconite natural modified.

Potencial antioxidante, mineral, inibitório de enzimas α-amilase e lipoxigenase e composição centesimal de espécies da família Apiaceae

Eryngium foetidum L., Eryngium cf. campestre and Coriandrum sativum L. are Apiaceae family vegetable appreciated due to its peculiar flavor and consumed mainly in the north and northeast of Brazil. The vegetables are rich in protein, vitamins, fiber, minerals, total phenolics and other essential bioactives for a balanced health. Nevertheless, many vegetables are falling into disuse by the population, instead of processed foods. The rescue consumption of these species is very important, aiming at their nutritional, therapeutic and antioxidant benefits. In this study, was quantified the levels of total phenolic, flavonoids and dihidroflavonoides by molecular absorption spectrophotometry in the ultraviolet. The total antioxidant capacity was also evaluated using five methodologies of in vitro assays: test Total Antioxidant Capacity (TAC), scavenging of DPPH and ABTS radical, Power Reducing and Power Chelating. It was also evaluated the power inhibitor of α-amylase and lipoxygenase extracts. All species showed significant levels of total phenolics, flavonoids and dihidroflavonoides in its composition. All treatments showed antioxidant activity of 50% except the sheets of E. cf. campestre, C. sativum and bracts of E. foetidum in DPPH and bracts of E. foetidum in ABTS. All treatments also exhibited 50% inhibition activity of the enzyme lipoxygenase.In α-amylase only the leaves of E. cf. campestre and C. sativum showed IC50. It was evaluate the phytochemical composition, aiming to meet the nutritional potential of Apiaceae family vegetables, called unconventional: Eryngium foetidum L., Eryngium cf. campestre; and conventional: Coriandrum sativum L. At the centesimal composition analysis Coriandrum sativum L. presented the highest levels of protein. The leaves of Eryngium foetidum L. exhibited higher values than other species in dietary fiber, while Eryngium cf. campestre detach with superior results in lipids. About the analyzed minerals, the leaves of Eryngium cf. campestre expressed results superior to the other in N, Ca, Mg, S and Cu. The amount of iron highlighted in sheets of E. foetidum, whereas P, K, Mn, Zn and B were most significant on leaves of C. sativum. It was concluded that the levels of total phenolic compounds found in these vegetables, characterize them for its high potential in the antioxidant and inhibition of lipoxygenase and α-amylase enzymes. Their protein and mineral levels classify them as species that can be used as a nutritional source in the preparation of other foods and may their regular consumption bring benefit to human health.

Compartimentos de K, Ca e Mg em solos e sua relação com o crescimento inicial, fisiologia e produtividade do eucalipto

Forestry has grown in a continuous and accelerated manner in Brazil, constituting a strategic activity for the generation of employment, income and tributes, favoring social and economic development of Brazilian agribusiness. The objectives of this study were: (1) evaluate the contents of K, Ca and Mg in the reserve compartments, non-interchangeable, interchangeable, available and the speed of its release, its correlations and its effects over productivity (annual average increment – AAI) of eucalyptus plantations, in forest sites cultivated in soils of the state of Rio Grande do Sul; (2) evaluate the initial growth, nutrition and physiological aspects of eucalyptus plants, cultivated with and without the addition of mineral sources of potassium (K), calcium (Ca) and magnesium (MG), in soils obtained from forest sites in the state of Rio Grande do Sul. In the first study, contents of K, Ca and Mg were evaluated in sulfuric digestion extract, boiling nitric acid, ammonium chloride, Mehlich-1 (only K), potassium chloride (Ca and Mg), as well as the release speed of these nutrients in the soil. In the second study, growth variables, nutritional aspects, photosynthetic rate (A) and transpiration rate of the plants (E) grown in distinct soils were evaluated under controlled conditions. The contents of K, Ca and Mg varied between compartments and depths in the studied soil classes, with the highest proportions found in the reserve compartment, indicating the importance of this compartment for the supplement of these nutrients at average and long terms. The great majority of K, Ca and Mg compartments presented significant correlations between each other, showing the dependence between them and the importance of evaluating the contents of these nutrients in the different compartments to adapt the nutritional management of the plants to each soil class, and to obtain continuous productions, minimizing the negative effects to the environment. Plants cultivated in soils that present larger reserves, availability and K, Ca and Mg release kinetics, presented similar height (H), stem diameter (SD) and shoot dry mass (SDM), with or without fertilization with K, Ca and Mg. The plants presented higher leaf content and accumulation of K in all soils fertilized with K, Ca and Mg.

Biofortificação com zinco, selênio e ferro, e biodisponibilidade de ferro em cultivares de feijoeiro-comum

The common bean (Phaseolus vulgaris L.), a staple food in nutritional diet of Brazilians and populations in developing countries, is a nutritionally rich legume with potential for biofortification. Approximately one third of the world population suffers from nutritional deficiencies, being necessary to increase the nutrient content in vegetables, especially iron (Fe), selenium (Se) and zinc (Zn), which are important micronutrients for plants and human health. In this context, three studies were carried out aiming to evaluate the potential of common bean cultivars to biofortification with Fe, Se and Zn, and verify the interaction between these minerals and iron bioavailability, in order to contribute to increased nutritional quality of grains, reducing the micronutrients deficiency and improving human health. In the first study, experiments were conducted in a greenhouse, with ten common bean cultivars in nutrient solution under different treatments with Fe, Se and Zn. The plant growth and the mineral content of the beans were evaluated in addition to verify the influence of polyphenol and phytate levels on Fe bioavailability in grains fortified with Zn and Se. The evaluated beans cultivars have proved promising for simultaneous biofortification with these nutrients without greatly affecting Fe bioavailability. In the second study, the aim was evaluate the interaction between Fe, Se and Zn in cultivars consumed in Brazil or in USA. Gene expression and root microscopy analysis were performed in order to understand the positive effect of Zn supply on the Fe uptake by roots. The expression of genes related to the transport and uptake of Fe and Zn did not clearly explain the influence of Zn in Fe nutrition. The roots microscopy and the evaluation of nutrient solutions used showed that, in the presence of Zn, there was Fe accumulation in epidermis of the roots and not in the vascular system, prone to be precipitated when it goes through the root membrane. In the latest study, a field experiment was conducted to evaluate the effect of Zn fertilization via soil and foliar, in the content and accumulation of Fe and Zn in grains and in the yield of common bean cultivars, in addition to verify the amount of these micronutrients supplied by biofortified beans. The fertilization with Zn did not affect the yield, but provided high levels of this nutrient in grains of the cultivars analyzed, representing 27% of the recommended daily intake of Zn. The higher Fe content in beans, obtained when there was no application of foliar Zn, supplies 56% of the daily requirement of Fe.