Antinociceptive activity of Maytenus rigida stem bark

Ethanol extract of Maytenus rigida stem bark and its fractions were assessed for antinociceptive activity in tail-flick test in rats. The activity was located in the chloroform, ethyl acetate and aq.methanol fractions. Phytochemical screening revealed that catechin was the only common class of compounds present on the ethanol extract as well as on the active fractions. 4'-Methylepigallocatechin, isolated from the ethyl acetate and aq.methanol fractions, showed antinociceptive effect in the tail-flick test (75 mg/kg; p.o.), which was reversed by the opiate antagonist naloxone (3 mg/kg; i.p.).     

Efficacy of adding chemical and microbial additives to silage on beef cattle performance: Systematic review and meta-analysis

The effects of different additives on farm-scale silage quality and beef cattle performance are inconsistent. This study aimed to carry out a systematic review and meta-analysis to evaluate the efficacy of chemical and microbial additives to silage on beef cattle performance. Systematic searches were performed using databases and scientific journals, and 42 articles were selected. Data for all variables were grouped into subgroups according to the additive type. For dry matter intake and average daily gain, the data were also grouped by forage type due to greater comparison numbers. The treatment mean differences and 95% confidence intervals (p < 0.05) were analysed using a random-effects model. The use of homo- and heterofermentative microbial inoculant mixtures and chemical additives (Ch) increased the average daily gain of beef cattle fed maize/sorghum silage. Homofermentative microbial inoculant (Ho), Ch, and a mixture of microbial inoculant and chemical additives also increased the average daily gain of beef cattle fed temperate grasses. Only Ch increased dry matter intake. Ch increased feed efficiency, and Ch and Ho increased carcass weight. The evaluated additives improved the silage fermentation process mainly via pH and ammonia nitrogen reduction. Overall, this meta-analysis demonstrated that silage additives improved the ensiling process and beef cattle performance, with better results with Ch use. Due to the aerobic stability and microbiological profile analyses being carried out more in laboratory-scale silos, more studies are needed to determine these silage parameters after opening the silo at the farm scale.     

Carbohydrate molecule size affects the metabolic and digestive dynamics of jundiá (Rhamdia quelen)

This experiment was conducted to study the effects of carbohydrates with different molecular sizes on growth performance, feed utilization and composition, activity of digestive enzymes, plasma and hepatic metabolites of jundiá (Rhamdia quelen). Triplicate groups of jundiá (4.08 ± 0.005 g) were stocked in 12 tanks with stocking density of 25 individuals per tank and fed for 40 days with four isonitrogenous diets (37%) and isocaloric diets (3,200 kcal/kg) containing fructose (FRU), sucrose (SUC), maltodextrin (MALDEX) or corn starch (CS). The results showed no significant differences for growth variables and digestive enzymes. Fish whose diet received maltodextrin showed higher levels of deposited body fat and hepatosomatic index. Moreover, the above‐mentioned treatment resulted in lower concentrations of glucose and cholesterol in the plasma of jundiá, higher levels of triglycerides, and lower reserves of glucose and liver glycogen. However, fish fed the starch‐based diet presented higher moisture content, crude protein deposition, and body protein retention coefficient. In that same treatment, the jundiá presented higher levels of plasma glucose and liver protein. In conclusion, the efficiency of using digestible carbohydrates in iso‐nutritional diets for jundiá depends on the size of their molecular structure. The corn starch was the best dietary carbohydrate source for jundiá, based on feed utilization and composition and greater synchronicity between energy utilization and protein synthesis.     

Biological and ecological aspects of the deep‐water red crab populations inhabiting isolated seamounts to the west of the Azores (Mid‐Atlantic Ridge)

Seamounts are common topographic features in the Mid‐Atlantic Ridge (MAR) including the Azores. However, the knowledge on the ecology of seamounts in this region remains scarce despite needs for assessment and management of seamount resources such as the developing fisheries for deep‐water crabs. We described here for the first time the biological characteristics of an unexploited virgin deep‐water red crab Chaceon affinis population on seamount areas of the MAR to test the hypothesis that its general life history characteristics are similar in different ecosystem types (coastal areas and seamounts) across Macaronesia. We used a randomly stratified design to prospect a layer between 600 and 900 m depth around the summit of two isolated seamounts off the Azores. Results were consistent with the literature information in relation to the patterns of depth distribution, size and sex structure, and reproductive aspects. On the other hand, seamounts showed higher abundances when compared to previously studied coastal areas. Abundance may be also different between seamount areas as a function of the suitable bottom type available and presence of hydrothermal vents. We recommend that the essential habitat of the species should be better mapped identifying vulnerable areas before the development of any fishery.     

Carbohydrate metabolism as related to high-temperature conditioning and peel disorders occurring during storage of citrus fruit

The aim of this research was to understand the involvement of the carbohydrate metabolism in physiological disorders occurring during the postharvest storage of citrus fruit. These disorders, manifested in the rind, depreciate fruit quality and often originate important losses. There has been increasing interest in the use of nonharmful treatments, such as high-temperature conditioning, to avoid citrus peel damage during fruit storage at low temperature in chilling-sensitive cultivars, but their influence in postharvest disorders occurring at nonchilling temperatures and the mechanisms related to them are poorly understood. The data obtained showed that heat conditioning (3 days/37 degrees C) increases the chilling tolerance of cv. Navelate fruit and favored sucrose, but not hexoses, accumulation and its maintenance after the fruit was transferred to low temperature. This effect was related to heat-induced increase in the activities of the sucrose-synthesizing enzymes sucrose phosphate synthase (SPS) and sucrose synthase (SS). Furthermore, sucrose levels and the activities of both enzymes were higher in cv. Pinalate oranges, a chilling-tolerant spontaneous abscisic acid deficient mutant of Navelate. In contrast, carbohydrates appeared not to be involved in the susceptibility of oranges to rind staining, a physiological disorder different from chilling injury, which mainly occurred at a nonchilling temperature (12 degrees C) and was not reduced by heat conditioning. The effect of low temperature in SS and SPS activities was less than that of high temperature, which might be related to the lower changes occurring in sucrose during fruit storage at 2 degrees C.     

Land use capability classification adaptation in low and intermediate technology farming systems: A soil erosion indicator

Land classification assists in identifying optimal crop selection for a given field, and land use capability gives an indication of potential agronomic productivity. However, these approaches are most germane to farming systems managed with high technology. This study sought to adapt land use capability to farming systems managed with low and intermediate levels of technology. Assessment of the classification criteria was conducted using erosion data as a primary indicator. The adapted (and currently in effect) criteria were compared in three regions in Minas Gerais, Brazil, each one representing one of the management levels. Erosion often results from inappropriate practices in land use or management. Therefore, maps of adequacy of land use and management were used to measure how well each one corresponded to the erosion map. The adapted criteria changed the spatial distribution of the classes of land use capability in different ways. Correspondence between the land use/management map and the erosion map increased from 71% to 88.5% when the criteria adapted to an intermediate level of management were used. It also increased from 62.9% to 66.7% when the criteria adapted to a low level of management were considered, better reflecting current erosion. Therefore, adopting adapted classification criteria is recommended for planning land use in locations where farming systems with low and intermediate levels of management are common, requiring re‐adaptation and reassessment depending on socio‐environmental factors.     

Can the Activities of Acetylcholinesterase and Glutathione S-Transferases of Crangon crangon (L.) be Used as Biomarkers of Fuel Oil Exposure?

This work aimed to determine the sensitivity of acetylcholinesterase (AChE) and glutathione S-transferases (GST) activities of Crangon crangon (L.) to the water-accommodated fraction (WAF) of the fuel oil spilled by the oil tanker Prestige, in order to assess their usefulness as markers for this kind of pollution. Laboratory exposure of shrimps to WAF of weathered Prestige fuel oil showed no significant interference with AChE activity. Significant induction of GST activity was observed, potentially as a result of high concentrations of polycyclic aromatic hydrocarbons. However, these results were only obtained with the higher WAF concentrations tested. It was concluded that AChE and GST activities of C. crangon were not useful biomarkers for short-term exposure to the WAF of fuel oil spilled by the tanker Prestige and carried to the beaches of Galicia (NW Spain).     

Drift across the Atlantic: genetic differentiation and population structure in Brazilian and Portuguese native goat breeds

Brazilian goat breeds are believed to derive mainly from animals brought by Portuguese settlers since the 16th century. We used microsatellite markers in a sample of 436 animals to study genetic variability and differentiation of the six Portuguese (PT) and six Brazilian (BR) goat breeds currently recognized in the two countries. These breeds were also compared with an outgroup represented by a sample of Alpine (ALP) goats. The effective number of alleles and allelic richness were slightly higher in PT than in BR breeds. The global F(ST) was nearly 0.11 when PT and BR breeds were considered, with a mean pairwise F(ST) of about 0.03 among PT breeds, 0.07 among BR breeds and 0.15 between PT and BR breeds. The dendrogram illustrating relationships between populations and the correspondence analysis indicate the existence of two very distinct clusters, corresponding to the countries of origin of the breeds studied, which are nearly equidistant from the Alpine outgroup. The analysis with structure confirmed the separation between PT and BR breeds but suggests that some BR breeds, especially Graúna and Canindé, may share a common ancestry with PT breeds. The divergence observed between PT and BR breeds may result from founder effects and genetic drift but could also reflect the introduction in Brazil of goats originating from other regions, e.g., West Africa.     

Nutritional efficiency of feed-restricted F1 Holstein/Zebu cows in early lactation

Tropical Animal Health and Production - The quantitative feed restriction of lactating cows has been used in intensive production systems as a strategy to reduce production costs. However, the...     

Ruminal degradation kinetics of diets with different lipid sources and its influence on intake and milk yield of early lactation crossbred Holstein × Gir cows

Tropical Animal Health and Production - The emergence of tick-borne diseases has been reported as a serious problem in public health worldwide and many aspects of its epidemiology and effects on...