Productive performance, nutrient digestion and metabolism of Holstein (Bos taurus) and Nellore (Bos taurus indicus) cattle and Mediterranean Buffaloes (Bubalis bubalis) fed with corn-silage based diets

The objective of this study was to evaluate the productive performance, nutrients digestion and metabolism of three different genetic groups fed with the same diet based on corn silage. 30 heifers in growth were used of three groups of cattle, the following: Nellore (Bos taurus indicus) (n = 10), Holstein (Bos taurus taurus) (n = 10), and Mediterranean buffaloes (Bubalis bubalis) (n = 10). The animals were fed in groups and received the same experimental diet composed of corn silage and concentrate for growing heifers. In the evaluation of animals the performance, consumption and total apparent digestibility of dry matter and nutrients with the aid of internal markers (chromic oxide) and external (iADF), rumen fermentation, excretion of purine derivatives, nitrogen balance and blood metabolites were measured. No differences were observed in animal performance. There were differences in nutrient intake and apparent digestibility of dry matter and nutrients in different groups of cattle. The concentration of ammonia nitrogen (NH3-N) and short chain fatty acids (SCFA) in the rumen were higher and lower, respectively, for the group of buffaloes in relation to other experimental groups evaluated. When considering the excretion of total purine derivatives, buffaloes showed the lowest value compared to other genetic groups evaluated; about 61.76% of the total genetic group Nellore and 57.62% of the total genetic group Holstein with an average of 33.67 mmol/day. For the buffaloes, the excretion of xanthine and hypoxanthine observed was of 5.11% of total purine derivatives. There was a better nitrogen balance (g/day) for groups of Holstein heifers and Nellore in relation to the group of buffalo heifers. There were differences in the concentrations of urea and urea nitrogen in serum and liver enzymes where the buffaloes had higher values in relation at the bovines. There is a great metabolic diversity among the experimental groups evaluated and it was more exacerbated among buffaloes and bovines, when submitted to the same diet and same management conditions. (C) 2011 Elsevier B.V. All rights reserved.

Influence of oil contamination on in vitro bond strength of bonding agents to dental substrates

Purpose: To evaluate the influence of cleaning procedures (pumice, anionic detergent and both procedures together) on the tensile bond strength of etch-and-rinse and self-etch adhesive systems to bovine enamel and dentin in vitro. Methods: Eighty non-carious, bovine incisors were extracted, embedded in acrylic resin to obtain enamel/dentin specimens. Flat bonding surfaces were obtained by grinding. Groups were divided according to substrate (enamel or dentin), adhesive system [etch-and-rinse, Adper Single Bond 2 (SB) or self-etch, Clearfil Protect Bond (PB)]; and cleaning substances (pumice, anionic detergent and their combination). The teeth were randomly divided into 20 groups (n=8): G1 - Enamel (E) + SB; G2 -E + oil (O) + SB; G3 - E + O + Pumice (P) + SB; G4 - E + O + Tergentol (T) + SB; G5 - E + O + P + T + SB; G6 - E + PB; G7 - E + O + PB; G8 - E + O + P + PB; G9 - E + O + T + PB; GIO - E + O + P + T + PB; G11 - Dentin (D) + SB; G12 D + SB + O; G13 - D + SB + O + P; G14 - D + SB + O + T; G15 - D + SB + O + P + T; G16 - D + PB; G17 - D + O + PB +; G18 - D + O + P + PB; G19 - D + O + T + PB; G20 - D + O + P + T + PB. Specimens were contaminated with handpiece oil for 5 seconds before bonding. Adhesive systems and resin composite were applied according to manufacturers` instructions. Specimens were tested in tension after 24 hours of immersion using a universal testing machine at a crosshead speed of 0.5 mm/minute. Bond strengths were analyzed with ANOVA. Failure sites were observed and recorded. Results: Tensile bond strength in MPa were: G1 (23.6 +/- 0.9); G2 (17.3 +/- 2.2); G3 (20.9 +/- 0.9); G4 (20.6 +/- 0.5); G5 (18.7 +/- 2.3); G6 (23.0 +/- 1.0); G7 (21.5 +/- 2.4); G8 (19.9 +/- 1.3); G9 (22.1 +/- 1.2); G10 (19.1 +/- 1.2); G11 (18.8 +/- 1.3); G12 (15.7 +/- 2.1); G13 (17.8 +/- 3.3); G14 (15.3 +/- 2.9); G15 (15.6 +/- 1.9); G16 (14.7 +/- 2.3); G17 (5.5 +/- 0.9); G18 (19.3 +/- 1.8); G19 (15.6 +/- 1.6); G20 (20.3 +/- 3.9). Statistical analysis showed that the main factors substrate and cleaning were statistically significant, as well as the triple interaction between factors of variance. However, the factor adhesive system did not show statistical difference. Oil contamination reduced bond strengths, being less detrimental to enamel than to dentin. Etch-and-rinse (SB) and two-step self-etch (PB) systems had similar bond strengths in the presence of oil contamination. For etch-and-rinse (SB), the cleaning procedures were able to clean enamel, but dentin was better cleaned by pumice. When self-etch (PB) system was used on enamel, anionic detergent was the best cleaning substance, while on dentin the tested procedures were similarly efficient.

Laboratory evaluation of the physicochemical properties of a new root canal sealer based on Copaifera multijuga oil-resin

Aim To compare a new root canal sealer based on Copaifera multijuga oil-resin (Biosealer) using three other established sealers (Sealer 26 (R), Endofill (R) and AH plus (R)) in terms of their physicochemical properties. Methodology The study was carried out according to the requirements of Specification Number 57 of the American Dental Association (ADA) and consisted of the following tests: setting time, flow, film thickness, dimensional stability, radiopacity and solubility/disintegration. Data were analysed statistically using anova and Tukey`s test for multiple comparisons. The significance level was set at 5% for all analyses. Results Sealer 26 (R) and AH Plus (R) had the longest setting time (P < 0.05). All materials presented flow in with the ADA`s guidelines. Regarding film thick-ness, Sealer 26 (R) did not have a satisfactory performance, as it had a higher mean value than the maximum allowed by the ADA (0.05 mm), being significantly different from the other materials (P < 0.05), which had mean values for film thickness in accordance with the ADA`s recommendations. Regarding the solubility and disintegration, only Endofill (R) did not meet the ADA`s specifications and presented the worst results of all materials (P < 0.05). Sealer 26 (R) presented the greatest dimensional changes and differed significantly from all other sealers (P < 0.05). Biosealer had the lowest radiopacity values and was significantly different from the other sealers (P < 0.05). Conclusion The experimental sealer based on Copaifera multijuga oil-resin presented satisfactory results in the physicochemical tests required by the ADA.

Inhibition of adventitious rooting in Backhousia citriodora F. Muell cuttings correlate with the concentration of essential oil

Backhousia citriodora is typical of the many commercially valuable woody Australian Myrtaceae species that are recalcitrant in forming adventitious roots from cuttings after maturation. A series of experiments were conducted to identify an endogenous rooting inhibitor in line with established criteria. Endogenous levels of citral were correlated with the rooting capacities of juvenile versus mature, and easy- versus difficult-to-root genotypes of B. citriodora, in both winter and summer. The biological activity of citral was confirmed in bioassays on mung beans and easy-to-root B. citriodora seedlings. Evidence of a common mechanism of root inhibition with other species in the Myrtaceae and the role of action of citral are discussed.

Genetic structure of a population of Ganoderma boninense on oil palm

Ganoderma boninense (the causal agent of basal stem rot of oil palm in Papua New Guinea) has a tetrapolar mating system with multiple alleles. Investigations into the population structure of G. boninense, using interfertility between isolates as a marker, revealed that the population on oil palm was comprised predominantly of genetically distinct individuals, although a number of isolates were found to share single mating alleles. No direct hereditary relationship was found between isolates on neighbouring or spatially separated diseased palms, indicating that outcrossing had probably occurred over several generations in the founder population prior to colonization of oil palm. In this study, a total of 81 A and 83 B mating type alleles (factors) were detected with 18 allelic repeats at the A locus and 17 at the B locus. Alleles appeared to be randomly dispersed throughout the population in each study block, although there was a significantly (P

Influence of planting date, method of handling and seed size on supersweet sweet corn seed quality

A supersweet sweet corn hybrid, Pacific H5, was planted at weekly intervals (P-1 to P-5) in spring in South-Eastern Queensland. All plantings were harvested at the same time resulting in immature seed for the last planting (P-5). The seed was handled by three methods: manual harvest and processing (M-1), manual harvest and mechanical processing (M-2) and mechanical harvest and processing (M-3), and later graded into three sizes (small, medium and large). After eight months storage at 12-14degreesC, seed was maintained at 30degreesC with bimonthly monitoring of germination for fourteen months and seed damage at the end of this period. Seed quality was greatest for M-1 and was reduced by mechanical processing but not by mechanical harvesting. Large and medium seed had higher germination due to greater storage reserves but also more seed damage during mechanical processing. Immature seed from premature harvest (P-5) had poor quality especially when processed mechanically and reinforced the need for harvested seed to be physiologically mature.

Effect of type of grain and oil supplement on the performance, blood lipoproteins, egg cholesterol and fatty ccids of laying hens

The effects of type of grain (wheat vs. sorghum) and oil supplement/kg diet [0, 20g olive oil (OL), 20g safflower oil (SO), 10 g OL plus 10 g SO (OLSO)], over a 12-week period on the performance, plasma and lipoproteins lipids [cholesterol (C), triglycerides (TG), phospholipid (P)], and yolk C and fatty acids concentrations of laying hens were studied. Hens fed on the sorghum diet had significantly (P

Simulation supplements field studies to determine no-till dryland corn population recommendations for semiarid western Nebraska

In a 2-yr multiple-site field study conducted in western Nebraska during 1999 and 2000, optimum dryland corn (Zea mays L.) population varied from less than 1.7 to more than 5.6 plants m(-2), depending largely on available water resources. The objective of this study was to use a modeling approach to investigate corn population recommendations for a wide range of seasonal variation. A corn growth simulation model (APSIM-maize) was coupled to long-term sequences of historical climatic data from western Nebraska to provide probabilistic estimates of dryland yield for a range of corn populations. Simulated populations ranged from 2 to 5 plants m(-2). Simulations began with one of three levels of available soil water at planting, either 80, 160, or 240 mm in the surface 1.5 m of a loam soil. Gross margins were maximized at 3 plants m(-2) when starting available water was 160 or 240 mm, and the expected probability of a financial loss at this population was reduced from about 10% at 160 mm to 0% at 240 mm. When starting available water was 80 mm, average gross margins were less than $15 ha(-1), and risk of financial loss exceeded 40%. Median yields were greatest when starting available soil water was 240 mm. However, perhaps the greater benefit of additional soil water at planting was reduction in the risk of making a financial loss. Dryland corn growers in western Nebraska are advised to use a population of 3 plants m(-2) as a base recommendation.

Eucalyptol, an essential oil, reduces contractile activity in rat cardiac muscle

Eucalyptol is an essential oil that relaxes bronchial and vascular smooth muscle although its direct actions on isolated myocardium have not been reported. We investigated a putative negative inotropic effect of the oil on left ventricular papillary muscles from male Wistar rats weighing 250 to 300 g, as well as its effects on isometric force, rate of force development, time parameters, post-rest potentiation, positive inotropic interventions produced by Ca2+ and isoproterenol, and on tetanic tension. The effects of 0.3 mM eucalyptol on myosin ATPase activity were also investigated. Eucalyptol (0.003 to 0.3 mM) reduced isometric tension, the rate of force development and time parameters. The oil reduced the force developed by steady-state contractions (50% at 0.3 mM) but did not alter sarcoplasmic reticulum function or post-rest contractions and produced a progressive increase in relative potentiation. Increased extracellular Ca2+ concentration (0.62 to 5 mM) and isoproterenol (20 nM) administration counteracted the negative inotropic effects of the oil. The activity of the contractile machinery evaluated by tetanic force development was reduced by 30 to 50% but myosin ATPase activity was not affected by eucalyptol (0.3 mM), supporting the idea of a reduction of sarcolemmal Ca2+ influx. The present results suggest that eucalyptol depresses force development, probably acting as a calcium channel blocker.

The effect of leaf area reduction on corn plants during the reproduction phase

Reduction in leaf area in corn plants during reproduction changes physiological metabolism and consequently the accumulation of dry matter in grains. The aim of this work was to study changes in agronomic characteristics caused by defoliation in corn during the reproduction phase. The experiment was carried out in Uberlândia, Minas Gerais state, in the agricultural year 2007/2008. The experiment was arranged in a randomized block design, consisting of seven treatments: control without defoliation, removal of two apical leaves, removal of four apical leaves, removal of all leaves above spike, removal of four intermediate leaves, removal of all leaves below spike, and removal of all plant leaves, with five repetitions. The genotype used for the evaluations was hybrid NB 7376. Defoliation was carried out when plants were at the growth stage R2. The variables assessed were: yield, density of spikes and corncobs, root resistance and stem integrity. When all leaves above the spike were removed, grain yield was reduced by 20%. Corncob density, stem integrity and root resistance to uprooting were also affected. Spike density was only affected when all plant leaves were removed. The leaf area remaining physiologically active above the spike was found to be most efficient in terms of grain yield.

No-till corn performance in response to P and fertilization modes

No-tillage systems provide soil changes that affect nutrient dynamics, hence, changing rates and forms of fertilizer application. This study aimed to evaluate the effect of phosphorus (P) and modes of nitrogen (N) and P application in corn under long-term no-tillage in a clayey Oxisol. Two experiments were carried out in the same experimental area and in the same year, in a randomized blocks design with four replications. In experiment I, the treatments consisted of five doses of phosphorus (0, 40, 80, 120 and 160 kg ha-1 of P2O5) applied in the sowing furrow. In experiment II, the treatments consisted of the N and P application modes (topdressing, in the sowing furrow and control - without N and P). Experiment I evaluated the root length, P uptake and grain yield and, the Experiment II, the firing height and yield. The P rates provided linear increases in root length in the 0-10 cm layer, P uptake and grain production. The different modes of application provided differences in the firing height and corn yield. The control treatment (0 kg ha-1 of N and P) provided the highest firing height, superior than those of topdressing and application in the furrow, which were not significantly different. The topdress application of N and P provided an increase in corn yield that exceeded 16 and 42% of the application in the furrow and the control, respectively. Thus, the results confirmed that increasing rates of P2O5, in soil with high initial P content, influence positively corn production factors, but with little significant responses, and the topdress application of N and P on soil with high P content, without water restriction, provided increased grain yield in relation to the application in the furrow.

Silicate fertilizer and irrigation depth in corn production

Calcium-magnesium silicates improve the soil physicochemical properties and provide benefits to plant nutrition, since they are sources of silica, calcium and magnesium. The objective of this study was to evaluate the grain yield of irrigated corn fertilized with calcium-magnesium silicate. The experiment was carried out in a greenhouse in Campina Grande - PB, Brazil, using plastic pots containing 80 kg of soil. The treatments consisted of the combination of four irrigation depths, related to water replacement of 50, 75, 100 and 125% of the crop evapotranspiration, with fertilizer levels of 0, 82, 164 and 246 g of calcium-magnesium silicate, with three replications. The experimental design was in randomized blocks, with the irrigation depths distributed in bands while the silicon levels constituted the subplots. Corn yield was influenced by calcium-magnesium silicate and by irrigation depth, obtaining the greatest grain yield with the dose of 164 g pot-1 irrigated at the highest water level. The water-use efficiency of in corn production tended to decrease when the irrigation depth was increased. The best water-use efficiency was observed when the irrigation level was between 87 and 174 mm, and the dose of silicate was 164 g pot-1.

Molybdenum mixed with glyphosate and alone via foliar spray in no-tillage common bean grown on corn stover

The effect of molybdenum (Mo) on common bean grown in desiccated corn stover in a no-tillage system was evaluated under two application modes: Mo mixed with the desiccant glyphosate and Mo direct spray to the bean leaves. The treatments (four replicates) were assigned to a completely randomized block design in a split-plot arrangement with the application of Mo (0, 100, 200, 400 and 800 g ha-1) mixed with glyphosate in the main plots and Mo foliar spray (0 and 100 g ha-1) in the sub-plots. The field experiments were carried out in 2009 and 2010 in the municipality of Coimbra, Minas Gerais State, with the common bean cultivar Ouro Vermelho. Mo mixed with glyphosate had neither an effect on common bean yield nor on the Mo and N contents in leaves, however it increased the Mo and N contents in seeds. Application of Mo via foliar spray increased Mo content in leaves and Mo and N contents in seeds. The reapplication of molybdenum with glyphosate for desiccation in subsequent crops caused a cumulative effect of Mo content in bean seeds.