Enhancement of growth and feed utilization of the European sea bass (Dicentrarchus labrax) fed supplementary dietary salt in freshwater

The effects of increased dietary sodium chloride supplement on growth, feed efficiency (FE), feed dispensed rate and fillet composition and morphological indices of European sea bass (initial weight of 4.9 g) were investigated in freshwater using five different levels of supplemental salt (0 (control diet, with no salt supplemented), 1%, 3%, 5% and 9% of diet). Over the experimental period of 50 days, the final weight of dietary salt (DS) groups was found to be approximately 19% higher than the control group. The final weight, specific growth rate and FE were greatest at the moderate level (1–5%) of salt supplementation. Optimum level of DS inclusion was calculated as 3%. Feed efficiency was significantly enhanced with increasing salt level up to 5%. A negative relationship between daily feed intake and FE (r²=0.66) was observed. The average muscle ratio (MR) in groups fed 1–5% supplemented salt was around 51.4% whereas fish receiving control and 9% salty diets had 5.3% lower MR (48.7%) (P<0.05). However, no significant effects of salt inclusion were found on viscera or hepatosomatic indices. Muscle ash and dry matter content slightly rose with increasing DS in the diet, but with no statistical difference (P>0.05). Similarly, no significant changes were observed in either muscle protein or lipid content among the groups (P>0.05).     

Determination of the Tissue Distribution of PPO on Caramote Prawn (Melicertus kerathurus,Forskal, 1755) and Jinga Shrimp (Metapenaeus affinis,H. Milne Edwards, 1837) Caught from Izmir

Tissue distribution of polyphenol oxidase (PPO) was studied in caramote prawn (Melicertus kerathurus) and jinga shrimp (Metapenaeus affinis) postmortem. Activity was analyzed in different tissues: the head (cephalothorax + carapace), carapace, exoskeleton of the abdomen, pereopods, and maxillipeds, individually. Based on the results, PPO activity of jinga shrimp was determined to be higher than caramote prawn during the research period. Partial tissue distribution showed that the highest activity was determined in carapace by using 70% ammonium sulfate fractions. Partial tissue distribution was also used to determine the spread of black spots. In addition, comparison between the PPO levels of caramote prawn and jinga shrimp was performed. The importance of these species is their economic value. However, there is no available data in the literature about caramote prawn and jinga shrimp. The determined data showed us that using antioxidant chemicals would be suitable for jinga shrimp.     

Effect of temperature and salinity on low thermal tolerance of Penaeus semisulcatus (Decapoda: Penaeidae)

Critical thermal minima (CTmin) and lower incipient lethal temperature (LILT) were determined for Penaeus semisulcatus juveniles at combinations of four acclimation temperatures (18, 22, 26 and 30 °C) and four salinity levels (20, 25, 30 and 35 ppt). While the CTmin and LILT of shrimps were not affected significantly by salinity ( P >0.05), a direct relationship was determined between the thermal minima values (CTmin, LILT) and the acclimation temperature ( P <0.05). The acclimation response ratio for the juveniles of P. semisulcatus had an interval of 0.18–0.32 in the current study.     

The amount of calcium in bony structures used for age determination in Cyprinion macrostomus (Heckel, 1843)

In this study, the ages of 76 individuals belonging to the Cyprinion macrostomus (Heckel, 1843) population caught from Murat River near Bingöl city were determined from six different bony structures and the level of calcium mineral of each bony structure was measured using an atomic absorption spectrophotometer. The determined element was statistically examined according to the age, length, weight and sex of the fish. The age, length and weight ranges of the fish were found to be 2–6, 12.0–21.2 mm and 16.3–135.3 g respectively. The relationships between the accumulation of calcium in all bony structures and the fish size (both length and weight) were found to be insignificant (P>0.05). However, a strong relationship was found between fish weight and accumulation of the mineral in vertebra and otolith. A strong correlation was also found between fish length and accumulation of calcium in the dorsal fin ray, followed by the otolith, vertebra and cleithrum bones respectively. Whereas the accumulation of calcium according to the age groups was found to be insignificant for scale and operculum (P>0.05), it was found to be significant for all the other bony structures examined (P<0.05). In conclusion, the accumulation of calcium on some bony structures of C. macrostomus was observed to increase with an increase in age, length and weight of fish, although the increases were not statistically significant at least for some bony structures (P>0.05).     

Effects of wastewater irrigation on soil and cabbage‐plant (brassica olerecea var. capitate cv. yalova‐1) chemical properties

The use of wastewater for irrigation is increasingly being considered as a technical solution to minimize soil degradation and to restore nutrient contents of soils. The aim of this study is to increase fertility and minimize degradation of soils irrigated with wastewater exposed to different purification treatments. A field experiment was conducted to investigate the effects of control and irrigation with wastewater, which had undergone different purification treatments, on macro‐ and micronutrient distribution within the soil profile and nutrient contents of cabbage (Brassica olerecea var. Capitate cv. Yalova‐1) in Erzurum, Turkey. Wastewater irrigation and preliminary treatment–wastewater irrigation significantly affected soil chemical properties especially at 0–30 cm soil depth and plant nutrient contents after one year. Application of wastewater increased soil salinity, organic matter, exchangeable Na, K, Ca, Mg, plant‐available P, and micro‐elements and decreased soil pH. Wastewater increased also yield and N, P, K, Fe, Mn, Zn, Cu, B, and Mo contents of cabbage plants. Undesirable side effects were not observed in plant heavy‐metal contents, due to salinity and toxic concentrations of metals from the application of wastewater to soil.     

Deficit irrigation of sunflower (Helianthus annuus L.) in a sub-humid climate

The response of sunflower (Helianthus annuus L.) to 14 irrigation treatments in a sub-humid environment (Bursa, Turkey) was studied in the field for two seasons. A rainfed (non-irrigated) treatment as the control and 13 irrigation treatments with full and 12 different deficit irrigations were applied to the hybrid Sanbro (Novartis Seed Company) planted on clay soil, at three critical development stages: heading (H), flowering (F) and milk ripening (M). The yield increased with irrigation water amount, and the highest seed yield (3.95 t ha⁻¹) and oil yield (1.78 t ha⁻¹) were obtained from the HFM treatment (full irrigation at three stages); 82.9 and 85.4% increases, respectively, compared to the control. Evapotranspiration (ET) increased with increased amounts of irrigation water supplied. The highest seasonal ET (average of 652 mm) was estimated at the HFM treatment. Additionally, yield response factor (k _y) was separately calculated for each, two and total growth stages, and k _y was found to be 0.8382, 0.9159 (the highest value) and 0.7708 (the lowest value) for the total growing season, heading, and flowering-milk ripening combination stages, respectively. It is concluded that HFM irrigation is the best choice for maximum yield under the local conditions, but these irrigation schemes must be re-considered in areas where water resources are more limited. In the case of more restricted irrigation, the limitation of irrigation water at the flowering period should be avoided; as the highest water use efficiency (WUE) (7.80 kg ha⁻¹ mm⁻¹) and irrigation water use efficiency (IWUE) (10.19 kg ha⁻¹ mm⁻¹) were obtained from the F treatment.     

Evaluation of Analytical Methods for Boron Determination in Maize Shoots

For the comparison of the digestion and spectroscopic determination methods used to measure boron (B) concentrations in maize shoots, increasing doses of boron (0, 2.5, 5, and 10 mg kg^?1 B) were applied to soil and maize plants (Zea mays L.) cultivar “Euralis Es Armandi” (FAO 640). The plants were grown under greenhouse conditions. Dried and ground maize shoots were digested according to two digestion procedures of microwave and dry ashing. Boron concentrations were determined using spectrophotometer and inductively coupled plasma-optical emission spectrometry (ICP-OES). The concentrations of boron influenced statistically (p < 0.01) due to the B applications and analysis methods. Spectrophotometric measurement of B amounts of the samples prepared with microwave digestion method was found irrelevant with other indicated methods. However, the ICP-OES measurements were found compatible with the dry ashing also with microwave digestion and suggested as a suitable method to determine boron contents of the maize shoots.     

Detection of antibodies to Borna disease virus in Turkish cats by using recombinant p40.

Recombinant p40 produced by baculovirus was used in an ELISA to screen samples of serum taken from 80 cats in Istanbul. The sera were also analysed for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Antibodies to Borna disease virus- (BDV) p40 were detected in 34 (42-5 per cent) of the 80 cats. Seventy-three per cent of the sera which were positive for FIV and 26 per cent of the sera which were negative for FIV had antibodies to BDV. There was no difference in the percentage of sera which were positive for BDV between the cats that were positive or negative for FeLV. Three of the cats had neurological disease and two of these had antibodies to BDV. Six sera with low, medium or high optical densities (ODS) by ELISA were analysed by Western blotting. Only the sera with medium and high ODS reacted specifically with p40 at a dilution of 1 in 1,000.     

Boron fertilization of Mediterranean aridisols improves lucerne (Medicago sativa L.) yields and quality

Abstract

Lucerne (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires boron (B) addition as the soils are naturally B deficient. Field experiments with four B-application rates (0, 1, 3, and 9 kg ha^?1 B) were conducted in 2005 and 2006 to determine the optimum economic B rate (OEBR), critical soil test and tissue B values for dry matter (DM) production for lucerne grown on B-deficient calcareous aridisols in eastern Turkey. Boron application increased yield at each site in both years of production. The OEBR and critical soil and tissue B content were not impacted by location. Averaged over the two years and three locations, the OEBR was 6.8 kg B ha^?1 with an average DM yield of 12.0 Mg ha^?1. The average soil B content at the OEBR was 0.89 mg kg^?1 while leaf and shoot tissue B content amounted to 51.8 and 35.5 mg kg^?1, respectively. Boron application decreased tissue calcium (Ca), zinc (Zn), and copper (Cu), and increased tissue nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), iron (Fe), and manganese (Mn). Tissue and soil B increased without impacting yield at B levels up to 9 kg ha^?1. We conclude that 7 kg ha^?1 B is sufficient to elevate soil test B levels from 0.11 to 0.89 mg kg^?1 and overcome B deficiency at each of the sites in the study. Similar studies with different soils and initial soil test B levels are needed to conclude if these critical soil and tissue values can be applied across the region.     

The effects of freeze‐and‐thaw cycles on phosphorus availability in highland soils in Turkey

Ongoing global warming may result in colder soil and thawing cycles and will increase the frequency of soil freezing‐and‐thawing‐treated cycles (FTCs) during winter in the cool‐temperate and high‐latitude regions. The purpose of this study was to determine the effects of repeated freeze–thaw cycles on the solubility and adsorption of P in lab and field experiments on Pellustert, Argiustoll, Haplustept, Fluvaquent, and Calciorthid soils, the major soil groups in E Turkey. The results demonstrated that, depending on the soil type, the freeze–thaw cycle could increase the adsorption and desorption of P within a certain temperature range. Repeated freezing and thawing decreased equilibrium P concentration (EPC) and increased P adsorption. EPC and P adsorption were strongly correlated with the number of FTCs. The highest P adsorption and the lowest P desorption was found in Pellustert followed by Argiustoll, Calciorthid, Haplustept, Fluvaquent when refrozen at –10°C for 15 d, then thawed at +2.5°C for 18 h, and 9 times FTC. However, in the field study, the adsorption value was lower than the value obtained from the laboratory condition. It appears that increasing the frequency of freeze–thaw processes depending on increase in temperature that leads to decreased plant‐available soil P pools, thus requires more P fertilizer in soil solution to supply adequate P during the plant‐growth period.