Effect of a dietary supplementation with linseed oil and selenium to growing rabbits on their productive performances,carcass traits and fresh and cooked meat quality

The present experiment tested a dietary supplementation with linseed oil and selenium to growing rabbits. The basal diet (B) contained 3% sunflower oil, while it was substituted with 3% linseed oil in the experimental feed (S). The selenium (Se) content of the two diets was 0.10 vs. 0.46 mg/kg. Rabbits were fed with B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age (group B), whereas the experimental groups were fed with S diet for 1, 2, 3 or 4 weeks (groups S1, S2, S3 and S4, respectively), before slaughtering (11 weeks of age). Live performance and carcass traits of rabbits, fatty acid (FA) profile and selenium content of their hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were considered in this study. In addition, the effect of two different cooking methods on the nutritional value of the enriched HL meat was also assessed. The tested dietary supplementation only minimally affected the live performance and carcass traits of rabbits. The S supplementation significantly reduced the Σ n‐6 FA and increased the Σ n‐3 FA of the HL meat and LTL meat, compared to the B diet (p < 0.001); thus, n‐6/n‐3 ratio was improved (p < 0.001). In addition, HL meat and LTL meat of S fed rabbits were significantly enriched in Se reaching a twofold increase in both meat cuts (p < 0.01). Therefore, the S supplementation improved the functional value of the rabbit meat. The heat treatment affected cooking loss, Se and vitamin E contents as well as the oxidative status of the HL meat (p < 0.001), with the different cooking methods providing different results. In addition, even if the beneficial C20:5 n‐3 and C22:6 n‐3 decreased with cooking, the n‐6/n‐3 ratio remained unaffected.     

Gold nanoelectrodes of varied size: transition to molecule-like charging

A transition from metal-like double-layer capacitive charging to redox-like charging was observed in electrochemical ensemble Coulomb staircase experiments on solutions of gold nanoparticles of varied core size. The monodisperse gold nanoparticles are stabilized by short-chain alkanethiolate monolayers and have 8 to 38 kilodaltons core mass (1.1 to 1.9 nanometers in diameter). Larger cores display Coulomb staircase responses consistent with double-layer charging of metal-electrolyte interfaces, whereas smaller core nanoparticles exhibit redox chemical character, including a large central gap. The change in behavior is consistent with new near-infrared spectroscopic data showing an emerging gap between the highest occupied and lowest unoccupied orbitals of 0.4 to 0.9 electron volt.     

Fish mortality due to acute ammonia exposure

Abstract. Fish mortality in the River Umia, near Villagarcia de Arosa, Pontevedra, Spain, which occurred after a discharge from a food sewage works, is studied. Physico-chemical parameters of water samples from sewage and from the River Umia were studied and concentrations of ammonia sufficiently high to cause toxic effects in fish (702 mg/1 and 302 mg/1 as total ammonia) were found. The toxicity of two concentrations of ammonia was investigated on goldfish, Carassius auratus (L.), using water quality values the same as found in the River Umia, to obtain the same concentrations of un-ionized ammonia (2·13 mg/1 and 0·91 mg/1). Fish exposed to high concentrations died within 24 h and three of six, which were exposed to the lowest concentration died within 96h. All fish at first showed symptoms of hyper excitability and hyperventilation, and at times of rest showed a decrease in respiration. Post-mortem findings generally included gill congestion and haemorrhage.     

Apoptosis in normal lymphoid organs from healthy normal, conventional pigs at different ages detected by TUNEL and cleaved caspase-3 immunohistochemistry in paraffin-embedded tissues

The frequency and the distribution of apoptotic cells were investigated in formalin-fixed paraffin-embedded lymphoid tissues from healthy conventional pigs at four different ages (6 days, 2 months, 3.5 months and 5 months). Samples of tonsil, mesenteric lymph node, spleen, thymus and Peyer's patches were histologically processed and apoptosis evaluated with the TUNEL reaction and cleaved caspase-3 immunohistochemistry. In each technique, quantification of positive labelling was done for each particular lymphoid tissue area. The labelling pattern and distribution were similar for TUNEL and cleaved caspase-3. TUNEL stained mainly apoptotic bodies inside macrophages, but signal was also seen in free apoptotic bodies and in the nuclei of lymphocyte-like cells. The anti-cleaved caspase-3 antibody labelled mainly nuclei of lymphocyte-like cells. All tissues presented a similar distribution pattern of apoptosis, except for the 6-day-old group. In this group, a scattered distribution of positive cells was detected in tonsil, lymph node and spleen. In the tonsil and mesenteric lymph nodes from the older pigs, follicular areas presented higher amounts of positive cells than interfollicular areas. Moreover, the splenic white pulp showed more positive reaction than the red pulp, especially when they included germinal centres. In all groups, the follicular areas of ileal Peyer's patches presented more labelled cells than the dome and the lamina propria. In the thymus, the higher apoptotic rates were found in the cortex. In general, TUNEL yielded higher rates of positive cells than cleaved caspase-3 immunolabelling. A good correlation between the two techniques was found for thymus, tonsil and mesenteric lymph node, but not for Peyer's patches and spleen. This study describes a detailed histochemical characterization of apoptosis in pig lymphoid tissues using TUNEL and a cleaved caspase-3 immunolabelling at different ages. Moreover, our results indicate that TUNEL and cleaved caspase-3 techniques can be equivalent only when tissues have a high or low levels of apoptosis, since a considerable discrepancy was found in intermediate situations. Data from this study should be useful for future comparative studies under disease conditions.     

VASA (DDX4) is a Putative Marker for Spermatogonia,Spermatocytes and Round Spermatids in Stallions

Expression of the protein DDX4/MVH, or VASA, has been reported in germ cells of several species. The main objectives of this study were to (i) investigate VASA expression patterns in testicular cells of stallions at two different reproductive stages (pre‐pubertal and post‐pubertal) and (ii) evaluate the use of VASA antibody as a molecular marker for single germ cells from stallions. Testicular tissues were obtained from stallions and categorized as pre‐pubertal and post‐pubertal based on the formation of lumen and status of spermatogenesis on the cross section of seminiferous tubules. The results of Western blot showed a VASA protein band located at 76 kDa, indicating that the rabbit antibody has a cross‐reactivity with horse testicular tissues. The result of immunolabelling showed that VASA was expressed in the cytoplasm of spermatogonia at both reproductive stages and in spermatocytes and round spermatids at the post‐pubertal stage. GATA4‐positive Sertoli cells and Leydig cells located in the interstitial space were not immunolabelled with VASA. These results suggest that VASA can be utilized as a molecular marker for germ cells of stallions at pre‐pubertal and post‐pubertal stages. Interestingly, immunolabelling intensity was significantly higher in pachytene spermatocytes compared to spermatogonia and round spermatid. VASA antibody was also effective for staining of single germ cell preparations. In conclusion, VASA protein expression can be used as a marker for identification of spermatogonia, spermatocytes and round spermatids in testicular tissues of stallions.     

Decreased thyroxine, triiodothyronine, and 5'-deiodination levels in malabsorption syndrome (runting or stunting syndrome) in artificially inoculated broilers

The effect of malabsorption syndrome (stunting or runting syndrome) on the thyroid function of broilers was investigated in control and inoculated broilers from 1 to 29 days of age. The broilers were infected at 1 day of age with intestinal homogenates from chickens naturally suffering from this syndrome. The body weight of inoculated broilers was significantly (P less than 0.05) lower 1 week after inoculation than that of controls. The level of thyroxine in the serum of inoculated birds was lower (P less than 0.05) from day 6 through the remainder of the trial. The level of triiodothyronine of inoculated birds was depressed (P less than 0.05) on day 4, but 1 week later it returned to normal. The earliest phenomenon indicative of disturbance of thyroid function was the significant depression of 5'-deiodination in liver homogenates of inoculated broilers as early as day 2. It is concluded that thyroid function is one of the earliest targets of this syndrome.     

Evaluation of drench treatments with phosphonate derivatives against Pseudomonas syringae pv. syringae on pear under controlled environment conditions

Several phosphonate derivatives including theoomycetic antifungal agents phosphonate andtris-o-ethylphosphonate (fosetyl), theethylene-releasing compound 2-chloroethylphosphonate(ethephon), and the antibiotic2-epoxypropylphosphonate (phosphomycin) were evaluatedfor in vitro and in planta activityagainst Pseudomonas syringae pv. syringae.Inhibition of colony growth in CYE agar byphosphonate, fosetyl and etephon was very slight(minimal inhibitory concentrations MIC= 0.31–;0.62 gHP /l). Also, survival of P. syringae pv. syringae in aqueous solutions ofphosphonate or fosetyl was high. Only phosphomycinshowed significant antibacterial activity invitro (MIC=10-20 µg HP /ml) comparedto streptomycin (1-2 µg a.i./ml). Potted pearplants irrigated with these chemicals and inoculatedwith Pseudomonas syringae pv. syringae had significantly less disease than non-treatedcontrols ( P<0.001). Phosphomycin was the mostactive compound with a median effective dose(ED₅₀) of less than 0.62 g HP /l.Activities of the other phosphonates were weak butconsistent between experiments. The ED₅₀s on wholeplants were 2.1, 3.3, and 6.9 g HP /l for ethephon, phosphonate and fosetyl, respectively. TheED₅₀of P. syringae pv. syringaeincreased from 6.5 in non-treated controls to 7.7-8.8log₁₀ cfu/ml on plants treated with phosphonatesat 1.86 g HP /l. It was concluded thatdrench treatment with fosetyl is not a practicaloption for control of P. syringae pv. syringae on pear.     

Development of a phenol-enriched olive oil with both its own phenolic compounds and complementary phenols from thyme

Besides affecting the oil's sensorial characteristics, the presence of herbs and spices has an impact on the nutritional value of the flavored oils. The aim of the study was to develop a new product based on the phenol-enrichment of a virgin olive oil with both its own phenolic compounds (secoiridoid derivatives) plus additional complementary phenols from thyme (flavonoids). We studied the effect of the addition of phenolic extracts (olive cake and thyme) on phenolic composition, oxidative stability, antioxidant activity, and bitter sensory attribute of olive oils. Results showed that flavonoids from thyme appeared to have higher transference ratios (average 89.7%) from the phenolic extract to oil, whereas secoiridoids from olive presented lower transference ratios (average 35.3%). The bitter sensory attribute of the phenol-enriched oils diminished with an increase of the concentration of phenols from thyme, which might denote an improvement in the consumer acceptance.     

Determination of isopropyl thioxanthone (ITX) in fruit juices by pressurized liquid extraction and liquid chromatography-mass spectrometry

A rapid LC-MS method, which compares different mass analyzers-single quadrupole, ion trap, and triple quadrupole-was developed for the quantitative determination of isopropyl thioxanthone (ITX) in fruit juices. ITX, a photoinitiator in UV-cured inks that can reach foods from the cartons for beverages in which they are used, was extracted from fruit juice samples with acetone/hexane (50:50) using pressurized liquid extraction. This method gave detection limits of 3, 3, and 0.01 microg/L and quantification limits of 10, 10, and 0.05 microg/L using single quadrupole, ion trap, and triple quadrupole, respectively. Five replicate fortifications of different fruit juices at the quantification limit gave recoveries oscillating between 68 and 72% with CV varying between 14 and 18%. This is the first report of a positive mass spectrometric identification and quantification of ITX in fruit juice samples packed in TetraPack. The sensitivity and specificity of the LC-MS/MS analysis using the triple quadrupole enables it to be the method of choice for risk assessment and monitoring. The method was applied to apricot, orange, peach, apple, grape and pineapple, and cherry and strawberry juices and to fruit nectars from Spain and Italy, and the ITX was detected in the range of 0.05-0.78 microg/L.