Citrus x aurantium essential oil as feed additive improved growth performance,survival, metabolic,and oxidative parameters of silver catfish (Rhamdia quelen)

The effects of dietary supplementation of graded level (0, 0.25, 0.5, 1.0, and 2.0 ml/kg diet) of Citrus aurantium essential oil (EOCA) on the growth, metabolic, and oxidative parameters of silver catfish (Rhamdia quelen) were investigated in a 60‐day growth trial. Fish fed with 2.0 ml EOCA per kg exhibited significantly better growth performance than those fed the control diet. Glucose, lactate, and protein levels in liver and muscle were altered significantly by dietary addition of EOCA. Hepatic lipid peroxidation levels, measured using thiobarbituric acid reactive substance and lipid hydroperoxides assays, were reduced in animals receiving the diet containing EOCA. Superoxide dismutase activity was higher, while glutathione S‐transferase activity was lower in the liver of fish receiving 0.5, 1.0, and 2.0 ml EOCA per kg of diet than in control. The nonprotein thiols content was higher in fish receiving the EOCA‐containing diet. Thus, dietary addition of EOCA improved growth, biochemical, and antioxidant parameters in silver catfish and could be useful as dietary supplement.     

Transportation of silver catfish, Rhamdia quelen, in water with eugenol and the essential oil of Lippia alba

This study investigated the effectiveness of eugenol and of the essential oil (EO) of Lippia alba when used in the transport of the silver catfish (Rhamdia quelen). These investigations involved measurements of blood (pH, PvO(2), PvCO(2) and HCO(3) (-)) and water parameters, survival and ionoregulatory balance. Fish (301.24?±?21.40?g, 28.90?±?1.30?cm) were transported at a loading density of 169.2?g?L(-1) for 4?h in fifteen plastic bags (7?L) divided into five treatments: control, 1.5 or 3.0?μL?L(-1) of eugenol and 10 or 20?μL?L(-1) of EO of L. alba. The water parameters were measured before (0?h) and after (4?h) transportation. The net Na(+), Cl(-) and K(+) losses were higher in fish from the control treatment compared to the other treatments. The PvO(2), PvCO(2) and HCO(3) (-) increased significantly in all of the treatments at the end of the transport period. In conclusion, based on the water (total ammonia nitrogen) and ionoregulatory indicators determined in the present study, our findings indicate that eugenol and the EO of L. alba are recommended for use in the transport of this species because these anesthetics apparently reduce stress.     

Effect of dietary electrolyte balance on production, immune response and mineral concentrations of the femur in broilers

The aim of this study was to assess the age-related effects of dietary electrolyte balance (DEB) on the performance, immune response (from day 0 to 42) and macromineral content of femur ash of broilers. The DEB values of the purchased commercial broiler diets were modified with the addition of NH4Cl or NaHCO3 to formulate the diets (DEB 325, 250, 175, 100, 25 and -50 mmol/kg) for this investigation. A total of 396 chickens were divided into 6 treatment groups and fed with the experimental diets for 6 weeks. During the first two weeks of life, DEB did not influence feed intake and body weight gain; however, by the 21st day of age DEB 175 and between 22 and 42 days of age DEB 250 mmol/kg gave significantly better results than the control. DEB did not affect the macromineral concentrations of bone ash. The immune response of broilers on low DEB (< 175 mmol/kg) was faster and more intensive than that of chickens on diets with medium or high DEB (> 175 mmol/kg). It can be concluded that the optimal DEB value required for the best body weight gain is significantly influenced by the age of broilers. Our results call attention to the discrepancy between the decreasing DEB level of commercial broiler diets and the age-related increase of 'electrolyte requirements' of broilers. It is also interesting that DEB may influence not only the performance but also the immune response of broilers.     

Assessing the impacts of the main river and anthropogenic use on the degree of metal contamination of oxbow lake sediments (Tisza River Valley,Hungary)

Journal of Soils and Sediments - Oxbow lakes, reaches that were cut off from a river during river straightening works, can accumulate during flooding metal-rich suspended sediments transported by a...     

Essential oil of Aloysia triphylla in Nile tilapia: anaesthesia,stress parameters and sensory evaluation of fillets

The optimum concentration of anaesthetic used to facilitate fish handling can be determined based on induction and recovery time, among other factors. This study aimed to evaluate the effectiveness of the essential oil of Aloysia triphylla (EOAT) as an anaesthetic in the handling of Nile tilapia juveniles. Nile tilapias exemplars were immersed at 0 (control group), 10, 20, 30, 40, 80, 150, 300 and 450 μL L^?1 EOAT to evaluate sedation, anaesthesia and recovery time. The stress response was evaluated by the determination of plasma glucose, cortisol, lactate and paraoxonase levels in anaesthetized (300 μL L^?1 EOAT) and non‐anaesthetized fish. Fillets from both groups were evaluated for organoleptic characteristics (taste and odour). Concentrations of 80–450 μL L^?1 EOAT were effective in inducing anaesthesia. There was a significant reduction in plasma cortisol levels one hour after handling in individuals anaesthetized with 300 μL L^?1 EOAT compared to the control group. Tasters did not detect differences in fillet taste and odour between fish exposed and not exposed to EOAT. A concentration of 300 μL L^?1 EOAT is recommended for handling Nile tilapia because it presents good anaesthetic induction and recovery times, causes a reduction in plasma cortisol levels one hour after handling and does not affect the taste or odour of the fillets.     

Effect of ripeness and postharvest storage on the phenolic profiles of Cherries (Prunus avium L.)

The phenolic compounds hydroxycinnamates, anthocyanins, flavonols, and flavan-3-ols of sweet cherry cultivars Burlat, Saco, Summit, and Van harvested in 2001 and 2002 were quantified by HPLC-DAD. Phenolics were analyzed at partially ripe and ripe stages and during storage at 15 +/- 5 degrees C (room temperature) and 1-2 degrees C (cool temperature). Neochlorogenic and p-coumaroylquinic acids were the main hydroxycinnamic acid derivatives, but chlorogenic acid was also identified in all cultivars. The 3-glucoside and 3-rutinoside of cyanidin were the major anthocyanins. Peonidin and pelargonidin 3-rutinosides were the minor anthocyanins, and peonidin 3-glucoside was also present in cvs. Burlat and Van. Epicatechin was the main monomeric flavan-3-ol with catechin present in smaller amounts in all cultivars. The flavonol rutin was also detected. Cultivar Saco contained the highest amounts of phenolics [227 mg/100 g of fresh weight (fw)] and cv. Van the lowest (124 mg/100 g of fw). Phenolic acid contents generally decreased with storage at 1-2 degrees C and increased with storage at 15 +/- 5 degrees C. Anthocyanin levels increased at both storage temperatures. In cv. Van the anthocyanins increased up to 5-fold during storage at 15 +/- 5 degrees C (from 47 to 230 mg/100 g of fw). Flavonol and flavan-3-ol contents remained quite constant. For all cultivars the levels of phenolic acids were higher in 2001 and the anthocyanin levels were higher in 2002, which suggest a significant influence of climatic conditions on these compounds.     

Chemical composition of the essential oil of Aloysia triphylla under seasonal influence and its anaesthetic activity in fish

Plants are sources of secondary metabolites, and some are rich in essential oils (EOs), which possess a bioactive pharmacological importance as sedatives and anaesthetics that have been experimentally demonstrated in fish. In search of products with lower residual effects and optimization of the production based on the local flora, the properties of the EO of Aloysia triphylla (EOAT) have been investigated. The samples of two years were analysed for the percentage variability of the chemical composition and the totality of the major components according to the season. Limonene, citral isomers (α and β), caryophyllene, caryophyllene oxide and spathulenol were the main constituents of the EOAT throughout these two years. In the second year, caryophyllene predominates over its oxide in all seasons; however, in the first year, it occurs only in autumn and winter. Seasonal pools of EOs were made for the biennium obtaining four samples, and silver catfish (Rhamdia quelen) juveniles were subjected to a concentration range of 20–800 μl/L EOAT in order to assess induction and recovery times of anaesthesia. The relationships between percentages of individual components in EOAT and time to induce deep anaesthesia indicate that its activity may be attributed to the association of several of its components.     

Effects of Leucaena biomass application in conjunction with fertilizers on cassava and taro yields in the Philippines

With the soaring cost and scarcity at times of inorganic fertilizers in the country, there is a need to find alternatives to inorganic fertilizers by making use of indigenous materials such as leaves of leguminous plants, mudpress, and so enhance growth and development of crops. Application of ‘ipil-ipil’ (Leucaena leucocephala) green manure supplemented with inorganic P and K caused vigorous growth of cassava (Manihot esculenta). Application of ipil-ipil biomass at the rate of 7.23 t ha−1 resulted in high yield and better values of yield components of cassava. However, due to high expenses incurred in hauling, transport and cost of the green manure materials, their use is likely to be more economical and feasible only if ipil-ipil is readily available in the farm. With taro (Colocasia esculenta), combined application of ipil-ipil green manure and inorganic P and K promoted vigorous stand and higher yield of the crop. Significantly larger corms were formed resulting in higher total corm yields and marketability than the control (untreated) and those treated only with 60–39.6–74.7 kg ha−1 N, P, and K from inorganic fertilizer. Increasing the rate of inorganic N applied to plants (90–36.9–74.7 kg ha−1 N, P, K) during a third cropping, gave comparable yield to treatment involving 7.23 t ha−1 ipil-ipil supplemented with inorganic P and K. Despite the relatively higher gross income obtained from organic and inorganic treatment combinations, slightly lower net income was obtained compared with inorganic fertilizer-applied plants due to higher production expenses incurred with the former treatments. This revised version was published online in June 2006 with corrections to the Cover Date.     

Gonadal recrudescence and induced spawning in Barbus altianalis

Gonadal recrudescence in Barbus altianalis from River Nile, Jinja (33°05E; 0°45N) Uganda was studied prior to induced spawning. Oocytes in B. altianalis were found to develop in cohorts suggesting batch spawning throughout the year with pronounced spawning activities coinciding with rainfall peaks of April and September. There was a strong positive correlation between rainfall and gonadosomatic index (r_S = 0.75, P = 0.008). B. altianalis had low fecundity (6.0 ± 2.0 per gram) and large‐sized eggs (2.97 ± 0.1 mm). Induced spawning was successful with exogenous hormones and water current. Results from this study suggested that total striping may not be appropriate, but larger eggs would confer high survival of offsprings under optimal conditions. The success registered in induced spawning of B. altianalis provides a breakthrough in seed production for multiplication and culture of this economically important fish species.