Níveis de energia digestível sobre os desempenhos reprodutivo e zootécnico e a deposição de lipídios nos hepatócitos de machos de tilápia-do-nilo

O experimento foi conduzido com o objetivo de avaliar o desempenho reprodutivo e zootécnico e a deposição de lipídios no tecido hepático de machos de tilápia-do-nilo alimentados com rações contendo diferentes níveis de energia digestível, obtidos com a inclusão de óleo de soja. Foram utilizados 400 reprodutores (300 fêmeas e 100 machos) distribuídos em delineamento inteiramente casualizado, composto de cinco níveis de energia digestível (2.700, 2.950, 3.200, 3.450 e 3.700 kcal.kg de ração-1) e quatro repetições. Os reprodutores foram alimentados com rações contendo 35% de proteína bruta e submetidos ao manejo reprodutivo em hapas por 101 dias. O melhor resultado de concentração espermática e percentual de espermatozoides normais foram obtidos para reprodutores alimentados com rações contendo 3.465,56 e 3.443,43 kcal. kg de ração-1, que produziram 7,98 × 10(9) espermatozoides.mL de sêmen-1 e 38,98% de espermatozoides normais, respectivamente. A produção de sêmen, o pH seminal, o índice de sobrevivência espermática e o tempo de ativação espermática não foram afetados pelos níveis energéticos das rações. Os níveis de energia das rações não influenciaram o desempenho zootécnico dos peixes, mas promoveram aumento linear na deposição de lipídios nos hepatócitos e afetaram a qualidade seminal, estimulando a produção de espermatozoides e a melhora dos índices de normalidade da morfologia espermática em níveis energéticos próximos a 3.450 kcal. kg de ração-1.

Efeito dos níveis de energia da ração sobre o desempenho e teor de gordura na carcaça de frangos de corte

It was studied the effect of energy levels in the diet, obtained from vegetal oil inclusion, on the performance, diet cost per kilogram of broiler and fat content of the carcass, There were used 4,800 broiler chicks, 2,400 males and 2,400 females, and they were distributed in six treatment (energy levels in kcal ME/kg of diet) in three different phases: start diet from one to 20 days of age: A - 2930, B - 2980, C - 3030, D - 3080, E - 3130, F - 3180, growth diet from 21 to 40 days: A - 2980, B - 3030, C - 3050, D - 3130, E - 3150, F - 3230, finishing diet from 41 to 45 days of age: A - 3030, B - 3080, C - 3130,, D - 3180, E - 3230, F - 3280. The protein content was 22, 20 and 18% in each phase, respectively, There were evaluated the feed intake, energy intake, protein intake, weight gain, feed conversion mortality, diet cost per kg/bw. Sixty broilers were slaughtered, five males and five females per treatment, randomly chosen to determine the carcass composition considering the dry matter content, lipids content and protein content, total fat in carcass and fat per kilogram of broiler. The data were submitted to variance analysis and the means were compared using SNK. The broilers fed with medium and low levels of dietary energy showed the highest weight gain. At energy levels of the treatment D in the three phases, the lowest cost per kilogram of broiler was obtained. The females presented the highest fat content per kilogram of broiler produced.

Validação de métodos para determinação do teor de 3-hidroxibutirato e 3-hidroxivalerato em polímero biodegradável

The efficiency of two methods for determining 3-hydroxybutyrate and 3-hydroxyvalerate content in the biopolymer (poly(3-hydroxybutyrate-co-3-hydroxyvalerate) has been evaluated. Both methods are based on (a) the hydrolysis of polymers, (b) the esterification with methyl (method A) and isoamilic alcohol (method B) and (c) analysis of the esters by gas chromatography using flame ionization detection (GC-FID). After optimization of the analytical conditions, the main validation parameters (linearity, quantification limit, detection limit, recovery, sensitivity and precision) were determined showing that both analytical procedures can be applied to control the process of poly(3-hydroxybutyrate) production. However, method B gives better analytical results than method A and has the advantage of not using chlorinated solvents.

Variabilidade espacial da resistência do solo à penetração e do teor de água em sistema de plantio direto na cultura da soja

A harmful and limiting factor regarding culture productivity is soil compaction, a parameter that can be quantified by the resistance of the soil to penetration and highly influenced by water content. These variables present spatial and temporary variability, characteristics which can be determined by the geostatistical technique. In the light of the above, the present work had as its objective the study of spatial variability of soil resistance to penetration (RP) and water content in the soil (U) in soy culture. The RP values at depths of 0,00-0,10; 0,11-0,20 and 0,21-0,30 m varied from 2,9 to 4,28 MPa and are considered harmful to the root development of legumes, although they have not influenced soy productivity which was 3887 kg ha(-1). The medium water content of the soil was between 0,210 and 0,213 kg kg(-1) for the three depths studied. The resistance of the soil to penetration, expressed through semivariograms, presented spatial dependence at all depths, being adjusted to the spherical model at depths of 0,00-0,10m and exponential at depths of 0,110,20 and 0,21-0,30 m. The spatial variability for all studied layers presented a range of about 20m. The water content in the soil did not present spatial dependence for the depths, presenting randomized distribution.

Relação lisina digestível: proteína digestível em rações para tilápias-do-nilo

This study was carried out to determine the best digestible protein/digestible lysine ratio that should be present in feed fed to Nile tilapias. Two hundred and sixteen tilapias (11.0 +/- 0.43g) were distributed in 36 fish tanks (205 L) at a density of 6 fish/tank. Twelve feeds were formulated with three different digestible protein (DP) levels 22.0; 26.0 and 30.0% (based on digestible amino acids) and four different lysine percentages of 4.5; 6.0; 7.5 or 9.0% in relation to digestible protein. The fish were fed ad libtum during a 60-day period. There was significant effect of the digestible protein and digestible lysine ratio on weight gain, because the increase in lysine levels in feeds with 26 and 30% DP promoted linear increase in this parameter. The best values for feed conversion were obtained at the levels 26 and 30% DP that increased the daily consumption of digestible protein. The lysine level caused a linear reduction in feed conversion and linear increase in the protein efficiency rate. The results suggested that the 26% DP level might be used in ration to feed Nile tilapia juveniles; however, these should contain digestible amino acids and the digestible lysine/digestible protein ratio should be 6.0%. However, for levels higher than 26% DP, a maximum digestible lysine level of 7.5% DP improved weight gain for the species.

Níveis de proteína digestível e energia digestível em dietas para tilápias-do-nilo formuladas com base no conceito de proteína ideal

This study was carried out to determine the best digestible energy and digestible protein ratio in feeds for Nile tilapia (Oreochromis niloticus) juveniles 30.0 +/- 4.21 g) based on digestible amino acids and the ideal protein concept). Twelve rations were formulated with protein levels 22.0; 26.0; 30.0 and 34.0% of digestible protein and levels 3,000, 3,300 and 3,600 kcal/kg digestible energy. The digestible energy/digestible protein ratio was between 8.94 and 15.19 kcal/g. Three hundred and twenty four tilapias were randomly distributed in thirty six 250 L circular tanks at a density of 9 fish/tank, a total of 12 treatments with three replications. After 60 days, there was no significant difference in weight gain, daily weight gain and feed conversion ratio among the studied treatments. A linear increase was observed in fillet yield with increasing digestible protein. With respect to feed cost/kg weight gain, the treatment with 30.0% DP and 3,000 kcal/kg DE presented low cost and better cost effectiveness index. Therefore, it was concluded that digestible energy did not influence the productive performance parameters and that effective feeds can be formulated with DP levels lower than 34% when feeding juvenile tilapias. The ration should be formulated based on the concept of ideal protein.

Efeito da extrusão termoplástica no teor de usina disponível da farinha desengordurada de grão-de-bico (Cicer arietinum, L.)

The aim of this research was to evaluate lysine availability of chickpea (Cicer arietinum, L.) flour submitted to thermoplastic extrusion at three feed moisture levels (13%, 18% and 27%). It was verified that extrusion treatments reduced available lysine by 58% and 55% at 13% and 18% feed moisture levels. The major lysine loss, 71%, was verified at 27% feed moisture level.

Efeitos da irrigação na sobrevivência, transpiração e no teor relative de água na folha em mudas de Eucalyptus grandis em diferentes substratos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Energia digestível para larvas de tilápia-do-nilo (oreochromis niloticus) na fase de reversão sexual

This experiment was conducted to evaluate different levels of digestible energy on the performance of Nile tilapia larvae (Oreochromis niloticus) during the sexual reversion phase. Three hundred and seventy-five larvae with initial average length and weight of 21.0±4.0 mg and 1.19±0.72 cm, respectively, were allotted to 25 30L-aquarium. A completely randomized design with five treatments and five replicates was used. The aquarium with 15 larvae was the experimental unit. The diets were formulated to contain levels of 3,300, 3,525, 3,750, 3,975, and 4,200 kcal/kg of digestible energy and to be isoprotein (38.6% digestible protein). The animals were fed ad libitum five times a day. At the end of the experiment, the averages of weight (PF), survival rate (SO), condition factor (FC) and length (CF) were analyzed. Linear reduction of fishes PF and CF, as the dietary digestible energy levels increased, was observed. No differences on fish SO and FC of different treatments were observed. Deleterious effects on performance due to the increasing dietary digestible energy levels were noticed for Nile tilapia larvae during the sexual reversion.

Reguladores vegetais na produção de biomassa e teor de óleos essenciais em Cymbopogon citratus (DC.) Stapf, em diferentes épocas do ano

The purpose of the present research was to evaluate the effect of plant growth regulators in biomass production and essential oil yield content in lemongrass (Cymbopogon citratus (DC.) Stapf), in different seasons. The experiment was conducted on São Manuel Experimental Farm, Faculdade de Ciências Agronômicas, UNESP - Botucatu. Which plants were randomly assigned into blocks to treatments with three repetitions. The treatments consisted of GA3 (50 and 100 mg L-1); Ethrel (100 and 200 mg L-1); CCC (500 and 1000 mg L-1); Alar 85 (1000 and 2000 mg L-1); Accel (20 and 40 mg 0L-1) and control. Four applications of plant growth regulators were realized every three months. After 40 days of each foliar spray, the plants were cut to determine the fresh weight and essential oil yield. The application of plant growth regulators did not increase the biomass production, showing difference among collect periods when the major production was detected at the fourth collect (summer). The greatest essential oil yield was found at the second collect (winter). In the present study, the used concentrations of plant growth regulators did not increase biomass neither essential oil yield.

Efeito dos níveis de triptofano digestível em dietas para codornas japonesas em postura

The adequate level (0.12, 0.16, 0.20, 0.24, and 0.28%) of the dietary digestible tryptophan was evaluated in 400 laying Japanese quail from 21 to 30 weeks old. The animals were housed in laying cages, with initial weight of 158.50 g and egg production average of 84.50%. A completely randomized blocks design, with eight blocks, five diets, eight replicates of ten birds per replicate and three experimental periods of 21 days each was used. Feed intake (g/bird/day), digestible tryptophan intake (mg/bird/day), egg production (%/bird/day), egg weight (g), egg mass (kg/bird/day) and feed conversion (kg feed intake per kg eggs and dozen eggs) were the characteristics evaluated. Only the characteristics digestible tryptophan intake and egg production rate show significant effects of digestible tryptophan levels in the diets. Performance response of the Japanese quails in posture, regarding the adjustment obtained through models of linear regression and broken-line regression model, and the biological interpretation, allow to conclude that to obtain the best productive performance, the Japanese quails diets should contain the level of 0.21% digestible tryptophan, that results in a daily intake of 45.0 mg/ bird of digestible tryptophan, corresponding to the digestible tryptophan: digestible lysine ratio of 21%. © 2008 Sociedade Brasileira de Zootecnia.

Micropropagação de Salvia officinalis L. com avaliação do teor de fenóis totais e atividade antioxidante

Stem cuts and seeds of Salvia officinalis were incubated on nutrient media for plantlets production and analysis of the total phenolic compounds, total flanovoids and antioxidant activity in micropropagated plants. Explants were obtained from seedlings and inoculated on MS with different concentrations of benzylaminopurine (BAP) and indolbutyric acid (IBA). After 30 and 60 days of incubation, the explants were scored for percentage of contaminated, dead and oxidized explants and mean bud numbers. For bud formation, the most efficient treatment was the medium containing BAP at 1 mg L-1, for the plantlet height the better medium was the control without the addition of plant regulator. IBA promoted the formation of few roots. Our results indicated that stem cuts incubated on media containing BAP and/or IBA did not increase the total flavonoid contents, but increased the total phenolics' by BAP and high antioxidant activity by 1 mg L-1 BAP.