Navegando por Autor "Cecon, P. R."

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Desempenho e rendimento de carcaça de bezerros alimentados com colostro fermentado, associado ao óleo de soja e zeranol
(Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2004-04) Mancio, A. B.; Castro, A. L. M.; Campos, W. E.; Pereira, J. C.; Cecon, P. R.
Utilizaram-se 40 bezerros Holandês × Zebu distribuídos em oito tratamentos (T): leite integral (1); leite integral com óleo de soja (2); leite integral e zeranol (3); leite integral com óleo de soja e zeranol (4); colostro fermentado (5); colostro fermentado com óleo de soja (6); colostro fermentado e zeranol (7); e colostro fermentado com óleo de soja e zeranol (8) com o objetivo de avaliar o consumo de alimentos, o crescimento e a conversão alimentar de animais entre o 15o e o 60o dia de vida. Diariamente, foram fornecidos 1,5kg de concentrado contendo 23% de proteína bruta, feno de tifton (Cynodon dactylon) à vontade e três litros de leite ou colostro fermentado. O colostro fermentado proporcionou melhores resultados de peso corporal e ganho de peso quando comparado ao leite integral, mas semelhantes aos resultados com zeranol. Também promoveu maior ingestão de matéria seca em relação ao leite integral, o que resultou em desempenhos semelhantes para esses dois tipos de alimento. Não houve diferenças entre os tratamentos quanto aos componentes não-integrantes da carcaça. O tratamento com leite e zeranol resultou em maior peso de carne industrial e o com óleo de soja aumentou a proporção de gordura interna. O colostro fermentado é uma boa opção para a recria de machos leiteiros e o efeito do zeranol sobre o ganho de peso é dependente da dieta dos animais.
Effects of Cu, Ni and Zn on lettuce grown in metal-enriched vermicompost amended soil
(Water, Air, and Soil Pollution, 2006-04-12) Jordão, C. P.; Fialho, L. L.; Cecon, P. R.; Matos, A. T.; Neves, J. C. L.; Mendonça, E. S.; Fontes, R. L. F.
A greenhouse experiment was conducted to test the effectiveness of cattle manure vermicompost enriched with Cu, Ni or Zn to increase plant yield. An oxisol amended with the metal-enriched vermicompost at the doses 0, 25, 50, 65, and 80 t ha^−1 was used to grow lettuce (Lactuca sativa L). After 39 days of growth, the plants were weighed for fresh and dry matter weight determinations. The soil amended with the vermicompost was analyzed for determination of DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Ni and Zn. The distribution of the metals in the plants was determined and the metal concentrations compared with the levels commonly found in plants, as well as with the range of the critical levels of toxicity to plants. Within each dose of 50, 65 and 80 t ha^−1 of the metal-enriched vermicomposts applied there was a decrease in lettuce yield as compared to the correspondent 50, 65 and 80 t ha^−1 doses of the natural vermicompost applied. The Cu concentrations in the lettuce leaves from the pots with vermicompost enriched with this element were in the range commonly found in plants (from 5.9 to 13.9 mg kg^−1), although in the roots they were relatively high (from 76.25 to 244.56 mg kg^−1). The Ni concentrations in the leaves from the pots with the vermicompost contaminated with this element were within the range of critical levels of toxicity to plants, i.e., from 10 to 50 mg kg^−1. In the case of Zn, its concentrations in the leaves from the pots with vermicompost enriched with this element were, in general, above the range of critical levels of toxicity to plants, i.e., from 200 to 500 mg kg^−1. The plants grown in soil amended with vermicomposts enriched with Cu and Ni showed high Cu and Ni concentrations in the roots, while the plants grown in soil amended with vermicompost enriched with Zn showed high Zn concentrations in the leaves. The correlation coefficients between the DTPA-extractable Cu, Ni and Zn and their concentrations in the plants varied from 0.835 to 0.950.
Heavy metal availability in soil amended with composted urban solid wastes
(Environmental Monitoring and Assessment, 2005-01-20) Jordão, C. P.; Nascentes, C. C.; Cecon, P. R.; Fontes, R. L. F.; Pereira, J. L.
A study was performed to evaluate the pH and the availability of Zn, Cu, Mn, Pb, and Ni in soil amended with increasing doses of composted solid wastes, collected in Rio de Janeiro, Rio de Janeiro State and in Coimbra, Minas Gerais State, Brazil. The influence of the time elapsed between compost application to the soil and the sampling of the plant growth substrate (soil + compost) for pH and metal availability analyses was also examined. The availability of heavy metals in the soil, in the compost and in the substrate was evaluated using DTPA solution for metal extraction. The increase of the compost doses added to the soil resulted in the increase of the pH in the substrate. The addition of the compost from the bigger city, Rio de Janeiro, resulted in higher increase in soil pH and available Zn, Cu, Pb, and Ni levels as compared to the addition of the compost from the smaller city, Coimbra. Increasing the time elapsed between the compost application to the soil and the sampling of the mixture resulted in higher available Zn, Cu, Mn, and Pb levels. The addition of the compost from Rio de Janeiro resulted in substrate metal concentrations in the order Zn > Pb > Ni > Cu > Mn and for the Coimbra compost the metal concentrations in the substrate was Zn > Pb > Cu > Ni > Mn. The higher values of pH and available metals obtained for the bigger city were attributed to the greatest metal contamination of its compost.
Influence of the antibiotic timentin on plant regeneration of tomato (Lycopersicon esculentum Mill.) cultivars
(Plant Cell Reports, 2000-01) Costa, M. G. C.; Nogueira, F. T. S.; Figueira, M. L.; Otoni, W. C.; Brommonschenkel, S. H.; Cecon, P. R.
Cotyledon explants of tomato (Lycopersicon esculentum Mill. cvs 'Santa Clara', 'Firme' mutant, 'IPA-5' and 'IPA-6') were excised from 8- to 10-day-old in vitro-grown seedlings. Four different shoot induction media supplemented with timentin (300 mg l–1) were screened. When cotyledon explants were cultured on MS-based medium with 1.0 mg l–1 zeatin plus 0.1 mg l–1 IAA and supplemented with timentin, higher regeneration frequencies and a greater number of elongated shoots were obtained. It was observed that timentin caused an increase in the morphogenesis of in vitro cotyledon explants of tomato cultivars. In two of three cultivars tested, rooting of shoots was positively influenced, both in the presence and absence of timentin in the rooting medium, among shoots regenerated from explants derived from timentin-supplemented medium. The results confirm those of a previous investigation on the beneficial effects of this class of antibiotics on tomato regeneration and, consequently, its reliability for use in the transformation of this species.