Paulo Roberto Cecon

Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial

BackgroundThe consumption of low glycemic index (LGI) foods before exercise results in slower and more stable glycemic increases. Besides maintaining an adequate supply of energy during exercise, this response may favor an increase in fat oxidation in the postprandial period before the exercise compared to high glycemic index (HGI) foods. The majority of the studies that evaluated the effect of foods differing in glycemic index on substrate oxidation during the postprandial period before the exercise are acute studies in which a single meal is consumed right before the exercise. The purpose of this study was to investigate the effect of consuming two daily HGI or LGI meals for five consecutive days on substrate oxidation before the exercise and in the concentrations of glucose, insulin and free fatty acids before and during a high intensity exercise.MethodsFifteen male cyclists, aged 24.4 ± 3.8 years, with body mass index of 21.9 ± 1.4 kg.m-2 and a VO2 max of 70.0 ± 5.3 mL.kg-1.min-1, participated in this crossover study. All test meals were consumed in the laboratory. On days 1 and 5, substrate oxidation (30 minutes before and 90 minutes after breakfast (HGI or LGI)) and diet-induced thermogenesis (90 minutes postprandial) were assessed before the exercise. The levels of glucose, insulin, and free fatty acids were determined during 2 h after breakfast on these same days. Ninety minutes after breakfast, subjects completed a 30 min cycloergometric exercise at 85 to 95% of their maximum heart rate, during which lactate concentrations were assessed.ResultsThe consumption of HGI meals resulted in higher areas under the glycemic and insulinemic curves in the postprandial period. However, glycemia did not differ by study treatment during exercise. There were no differences in free fatty acids in the postprandial period or in lactate levels during exercise. LGI meals resulted in lower fat oxidation and higher carbohydrate oxidation than the HGI meal in the postprandial period.ConclusionsThe results do not support a differential glycemia according to glycemic index during exercise. The ingestion of LGI foods did not lead to higher fat oxidation relative to the ingestion of HGI foods.Trial registrationACTRN: ACTRN12609000522213

Produção de fitomassa, acúmulo de nutrientes e fixação biológica de nitrogênio por adubos verdes em cultivo isolado e consorciado

The objective of this work was to evaluate the effects of sole and intercropping systems of the summer green manures sunnhemp (Crotalaria juncea) and millet (Pennisetum americanum) in phytomass yield, content and accumulation of nutrients and biological nitrogen fixation (BNF). The experimental design was a randomized complete block with four replicates, and treatments consisted of green manures sunnhemp, millet, sunnhemp + millet and spontaneous vegetation. The sunnhemp stood out in the phytomass yield, being 108% greater than the spontaneous vegetation and 31% superior to millet. In the sunnhemp + millet intercropping, the leguminous contributed with 65% of the total dry matter. The presence of sunnhemp resulted in larger contents of N and Ca, while millet and the spontaneous vegetation showed larger content of potassium. The accumulation of P and Mg was strongly influenced by the phytomass yield, reaching high values in the presence of sunnhemp, while the accumulation of N and Ca was a result of the largest contents as well as the largest phytomass yield in the treatments with the leguminous. The BNF was 61% in the intercropping and 57% in sole cropping, incorporating to soil via BNF 89 and 173 kg/ha of N, respectively, being an excellent strategy for increasing soil nitrogen.

Consumo e digestões totais e parciais em novilhos F1 Limousin x Nelore alimentados com dietas contendo cinco níveis de concentrado

ABSTRACT - A trial was conducted to evaluate the effects of five dietary concentrate levels on the intake and total and partial apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO), neutral detergent fiber (NDF), and non structural carbohydrates (NSC). Five rumen, abomasum and ileum fistulated F1 Limousin x Nellore bulls were full fed diets containing 25.0, 37.5, 50.0, 62.5, and 75.0% of concentrate and allotted to a 5 x 5 Latin square design. The chromic oxide was used as an external marker to determine the total and partial digestibility. The addition of crescent concentrate amounts to the diet resulted in linear increases in the DM, OM, NCE, CP, EE, and TDN and reductions in NDF intake. The total apparent digestibility of DM, OM, CP, EE, CHO, and NSC linearly increased with the increment of the dietary concentrate levels. The CP apparent digestibility in the small intestine linearly increased as function of the concentrate addition in the diets. The concentrate levels in the diet did not influence the rumen and post-rumen NDF apparent digestibility. The dietary NDF levels reduction resulted on linear increases of NDT and DM total apparent digestibility.

Parâmetros genéticos em café Conilon

O objetivo deste trabalho foi avaliar a produtividade e obter as estimativas de parâmetros geneticos e nao geneticos de 40 materiais geneticos do programa de melhoramento genetico de cafe Conilon do Incaper, no Estado do Espirito Santo. Foram analisados dados de dois experimentos, nos municipios de Marilândia e Sooretama, ES, nas safras de 1996, 1997, 1998, 1999, 2000, 2001 e 2002, em que se avaliaram 16 caracteristicas. Realizou-se, inicialmente, a analise de variância individual, por local em cada ano, com base na media de parcelas, em blocos ao acaso. Posteriormente foi feita a analise de variância conjunta. Os genotipos apresentaram grande variabilidade genetica para a maioria das caracteristicas avaliadas. Os elevados coeficientes de determinacao genotipico e coeficientes de variacao geneticos, associados as altas produtividades e a variabilidade genetica indicam a possibilidade de obtencao de exitos em programas de melhoramento genetico para diferentes caracteristicas avaliadas nos dois municipios.

Polymorphism in the PPARgamma2 and beta2-adrenergic genes and diet lipid effects on body composition, energy expenditure and eating behavior of obese women

In order to evaluate the effect of polymorphism in the PPARgamma2 and beta2-adrenergic genes and diet lipids on body composition, energy expenditure and eating behavior of obese women, 60 subjects were submitted to anthropometric, biochemical, dietary, molecular, basal and postprandial metabolism (indirect calorimetry) and eating behavior (visual analog scale) evaluation. Fat and saturated fatty acid (SFA) high diet was used to assess postprandial metabolism. The frequency of Pro12Pro/Gln27Gln, Pro12Pro/Gln27Glu, Pro12Pro/Glu27Glu and Pro12Ala/Gln27Glu genotypes was 35.71%, 30.37%, 23.21% and 10.71%, respectively. These values were not significant (p>0.05) for the dietary, anthropometric, biochemical and metabolic parameters. The Pro12Ala/Gln27Glu group was found to present greater energy used in postprandial period (EUPP). The presence of the PPARgamma2 gene variant, independent of beta2-adrenergic gene polymorphism, resulted in fat oxidation increase. Also, this group presented higher satiety, compared to the Pro12Pro/Gln27Gln group. The presence of the variant alleles in the PPARgamma2 gene suggests benefits in food intake control.

Fontes nitrogenadas e uso de Sacharomyces cerevisiae em dietas à base de cana-de-açúcar para novilhos: consumo, digestibilidade, balanço nitrogenado e parâmetros ruminais

O objetivo do presente estudo foi avaliar os efeitos das fontes nitrogenadas e o uso de Sacharomyces cerevisiae em dietas a base de cana-de-acucar sobre os consumos e as digestibilidades aparentes totais e parciais de materia seca (MS), materia orgânica (MO), proteina bruta (PB), extrato etereo (EE), carboidratos totais (CHO), fibra em detergente neutro (FDN) e carboidratos nao-estruturais (CNE), o balanco nitrogenado e os parâmetros ruminais. Foram utilizados quatro novilhos Holandes-Zebu, fistulados no rumen e abomaso, alimentados com quatro racoes a base de cana-de-acucar, constituidas de duas fontes nitrogenadas (ureia ou cama de frango) combinadas com dois niveis de Sacharomyces cerevisiae (0 e 10 g/dia). Utilizou-se delineamento em quadrado latino 4 x 4. A fibra em detergente neutro indigestivel (FDNi) foi utilizada como indicador, para determinar as digestibilidades aparentes totais e parciais. Os consumos de MS, MO, EE, CT e CNE nao foram influenciados pelas fontes nitrogenadas e pela utilizacao de Sacharomyces cerevisiae. Os consumos de PB e FDN foram maiores para as dietas suplementadas com cama de frango. Os coeficientes de digestibilidades totais de PB e EE foram maiores para as dietas constituidas de ureia. As digestibilidades aparentes totais de MS, MO, CT e FDN nao foram influenciadas pelas fontes nitrogenadas e pela utilizacao de Sacharomyces cerevisiae. O pH do liquido ruminal decresceu linearmente para as dietas suplementadas com ureia e apresentou comportamento quadratico, quando estas dietas foram combinadas com Sacharomyces cerevisiae. As concentracoes de amonia no liquido ruminal apresentaram comportamento quadratico, estimando-se valores maximos de 16,90; 26,12; 18,48; e 14,40 mg/100 mL para os tratamentos constituidos de cana-de-acucar e ureia; cana-de-acucar, ureia e Sacharomyces cerevisiae; cana-de-acucar e cama de frango; e cana-de-acucar, cama de frango e Sacharomyces cerevisiae, respectivamente.

Desempenho e características de carcaça de novilhos suplementados no período das águas

The effects of concentrate supplementation of steers during the rainny season on the performance and physical and traits of the carcass were evaluated. Fourty nine crossbreds steers were used, maintained on pastures of Brachiaria decumbens. The experiment was carried out in three experimental periods, according to a complete randomized design. The following supplements were daily fed at 10 a.m.: mineral salt (SALT), corn and soybean meal based supplements, with 20% CP, at the levels of 1.0 and 2.0 kg (CSBM1 and CSBM2) and wheat bran and soybean meal based supplements, with 20% CP, at the levels of 1.0 and 2.0 kg (WMSBM1 and WMSBM2). There was no treatment effect on average daily gain (ADG) and body weight (BW). The ADG were: 0.887, 0.936, 1.047, 0.943 and 1.012 kg/animal/day, respectively, for the treatments SALT, CSBM1, CSBM2, WMSBM1 and WMSBM2. The animals submitted to the different treatments did not exhibit differences in the physical and chemical characteristics of the carcass. No differences were observed for the steers carcass yield, which was, in average, of 52.19%.

Sample size for full-sib family evaluation in sugarcane

The objective of this study was to determine the minimum number of plants per plot that must be sampled in experiments with sugarcane (Saccharum officinarum) full-sib families in order to provide an effective estimation of genetic and phenotypic parameters of yield-related traits. The data were collected in a randomized complete block design with 18 sugarcane full-sib families and 6 replicates, with 20 plants per plot. The sample size was determined using resampling techniques with replacement, followed by an estimation of genetic and phenotypic parameters. Sample-size estimates varied according to the evaluated parameter and trait. The resampling method permits an efficient comparison of the sample-size effects on the estimation of genetic and phenotypic parameters. A sample of 16 plants per plot, or 96 individuals per family, was sufficient to obtain good estimates for all traits considered of all the characters evaluated. However, for Brix, if sample separation by trait were possible, ten plants per plot would give an efficient estimate for most of the characters evaluated.

Exigência nutricional de treonina digestível para galinhas poedeiras no período de 34 a 50 semanas de idade

With the objective to establish the nutritional requirement of threonine for light and semi-heavy laying hens in the period from 34 to 50 weeks old, 580 laying hens (half Lohmann and half Lohmann Brown) submitted to a basal ration containing 2.850 kcal ME/kg, 14.0% CP, supplemented of five levels (0.00, 0.035, 0.07, 0.105, and 0.140%) of L-threonine, in order to provide 0.410, 0.445, 0.480, 0.515, and 0.550% of digestible threonine in the rations. A 5 x 2 (threonine level and [...]

Seleção de plantas com potencial para fitorremediação de tebuthiuron

This study aimed to select tebuthiuron- tolerant plants to use them in phytoremediation programs in contaminated soils. The evaluated species were: Amaranthus hybridus, Crotalaria juncea, C. hyssopifolia, Chamaesyce hirta, Canavalia ensiformes, Helianthus annus, Pennisetum typhoides, Estizolobium aterrimum, Raphanus raphanistrum and Crotalaria incana. The experiment was carried out in a greenhouse, with a sandy-clay soil with 2.18 dag kg-1 of organic matter, in pots of 3 dm3 capacity. The experiment was arranged in a 10 x 4 x 4 factorial scheme in a randomized block design with three replications. The treatments consisted of: 10 species, four tebuthiuron doses (0.0; 0.5; 1.0 e 2.0 kg ha-1) applied in pre-emergence, and four evaluation times (15, 30, 45, and 60 days after sowing). Phytotoxicity, plant height and, above-ground, root and total biomass dry matter were evaluated. Canavalia ensiformes and Pennisetum typhoides were tolerant to tebuthiuron at the dose of 0.5 kg ha-1, and Estizolobium aterrimum up to the dose of 1.0 kg ha-1, with the latter showing less phytotoxicity symptoms and a smaller reduction of plant height, above-ground, root, and total biomass dry matter, as compared to the control treatment.