Effects of foliar spray of two kinds of zinc oxide on the growth and ion concentration of sunflower cultivars under salt stress

This study investigated the effects of foliar application of normal and nano-sized zinc oxide on the response of sunflower cultivars to salinity. Treatments included five cultivars (‘Alstar’, ‘Olsion’, ‘Yourflor’, ‘Hysun36’ and ‘Hysun33’), two salinity levels [0 and 100 mM sodium chloride (NaCl)], and three levels of fertilizer application. Fertilizer treatments were the foliar application of normal and nano-sized zinc oxide (ZnO). Foliar application of ZnO in either forms increased leaf area, shoot dry weight, net carbon dioxide (CO₂) assimilation rate (A), sub-stomatal CO₂ concentration (Ci), chlorophyll content, Fv/Fm, and Zn content and decreased Na content in leaves. The extent of increase in chlorophyll content, Fv/Fm and shoot weight was greater as nano-sized ZnO was applied to the normal form. The results show that the nano-sized particles of ZnO compared to normal form has greater effect on biomass production of sunflower plants.     

Effects of dietary administration of Echinacea purpurea on growth indices and biochemical and hematological indices in rainbow trout (Oncorhynchus mykiss) fingerlings

This study was conducted to evaluate the effects of Echinacea purpurea (EP) on growth and some hematological and blood biochemical indices of rainbow trout fingerlings. A basal diet was supplemented with 0 (control), 0.25, 0.5, 1, and 2 g EP kg?1 to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish with an initial average weight of approximately 8 g. After 8 weeks of feeding trial, fish fed diets with 0.25 and 0.5 g EP kg?1 showed highest final weight and SGR and fish fed with the control diet indicated the lowest final weight and SGR. There was a significant (P < 0.05) decrease in FCR between the control group and the groups fed with diets of 0.25 and 0.5 g EP kg?1. Biochemical parameters such as serum total protein content, albumin content, globulin content, and albumin/globulin ratio in the fish were evaluated. There were significant differences between hematological parameters including RBC, WBC, HB, lymphocyte, and neutrophil percentage in fish fed with dietary nucleotide compared with control treatment (P < 0.05). The results suggest that EP administration at 0.25 and 0.5 g EP kg?1 exerted positive effects on growth and biochemical and hematological indices in rainbow trout.     

From farm to fork--Mycobacterium avium ssp. paratuberculosis (MAP) as zoonotic agent?

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of the paratuberculosis (Para Tb) in ruminants. In addition, this pathogen has been suspected to be implicated in the pathogenesis of Morbus Crohn disease (MC), causing chronic inflammatory intestine changes of humans. The participation of MAP in this illness is discussed intensively and has very contradictory opinions. On the one hand several times succeeded in proving MAP DNA in changed human tissues as well as, in recent time, the bacteria has been isolated from patient's blood. On the other hand there are many publications which support the opposite opinion. In critical evaluation of already available data, therefore the hypothesis can be formulated that MAP could possibly take part in the MC of humans. The reliable verification of this hypothesis will only be possible, if the diagnostic procedures can be refined upon the substantial deficit concerning the sensitivity and/or specificity of the diagnostic methods. In addition, till now there is lack of optimized statistically case control studies. The conceivable transmission of the bacteria to humans by the direct animal contact has been considered as possible vector, furthermore, MAP has been detected in pasteurised milk and other food of animal origin. The prevalence data, usually estimated by ELISA for milk cattle stock show over 80% prevalence in many counties of the Federal Republic of Germany with an individual case prevalence ranging between 1% and 17% in different stocks. Comparable data are present also from other countries as well as for small ruminants. MAP has been concerned as a global problem, moreover the high spreading rate of MAP in wild animal populations as well as the considerable ability of the bacteria to survive in different stages of the infectious- and contamination-cycle, which might hardly be broken through. Thus it requires intensive research efforts for the development of the methodical diagnostic process as basis for valid epidemiological investigations of animals, humans and food.     

Transmission of sheep scrapie to elk (Cervus elaphus nelsoni) by intracerebral inoculation: final outcome of the experiment.

This is a final report of an experimental transmission of sheep scrapie agent by intracerebral inoculation to Rocky Mountain elk (Cervus elaphus nelsoni). It documents results obtained in experimental (n = 6) and control (n = 2) elk. During the first 2 years postinoculation (PI), 3 animals died or were euthanized because of infection or injuries other than spongiform encephalopathy (SE). In years 3 and 4 PI, 3 other inoculated elk died after brief terminal neurological episodes. Necropsy of these animals revealed moderate weight loss but no other gross lesions. Microscopically, characteristic lesions of SE were seen throughout the brain and spinal cord, and the tissue was positive for proteinase K-resistant prion protein (PrPres) by immunohistochemistry (IHC) and by Western blot. Scrapie-associated fibrils (SAF) were observed by negative-stain electron microscopy in the brain of elk with neurologic signs. PrPres and SAF were not detected in the 3 inoculated elk necropsied during the first 2 years or in the 2 control animals. Retrospective analysis of the gene-encoding cervid PrP revealed a polymorphism at codon 132. The elk with SE were either homozygous (MM) or heterozygous (LM). These findings confirm that intracerebral inoculation of sheep scrapie agent results in SE with accumulations of PrPres in the central nervous system of elk. Based on morphologic and IHC findings, the experimentally induced SE cannot be distinguished from chronic wasting disease of elk with currently available diagnostic techniques.     

Experimental transmission of chronic wasting disease agent from mule deer to cattle by the intracerebral route.

This communication reports final observations on experimental transmission of chronic wasting disease (CWD) from mule deer to cattle by the intracerebral route. Thirteen calves were inoculated intracerebrally with brain suspension from mule deer naturally affected with CWD. Three other calves were kept as uninoculated controls. The experiment was terminated 6 years after inoculation. During that time, abnormal prion protein (PrP(res)) was demonstrated in the central nervous system (CNS) of 5 cattle by both immunohistochemistry and Western blot. However, microscopic lesions suggestive of spongiform encephalopathy (SE) in the brains of these PrP(res)-positive animals were subtle in 3 cases and absent in 2 cases. Analysis of the gene encoding bovine PRNP revealed homozygosity for alleles encoding 6 octapeptide repeats, serine (S) at codon 46, and S at codon 146 in all samples. Findings of this study show that although PrP(res) amplification occurred after direct inoculation into the brain, none of the affected animals had classic histopathologic lesions of SE. Furthermore, only 38% of the inoculated cattle demonstrated amplification of PrP(res). Although intracerebral inoculation is an unnatural route of exposure, this experiment shows that CWD transmission in cattle could have long incubation periods (up to 5 years). This finding suggests that oral exposure of cattle to CWD agent, a more natural potential route of exposure, would require not only a much larger dose of inoculum but also may not result in amplification of PrP(res) within CNS tissues during the normal lifespan of cattle.     

A possible involvement of gibberellin in the mechanism of Avenafatua resistance to triallate and cross-resistance to difenzoquat

Avena fatua L. populations from numerous fields in Alberta have simultaneously developed resistance to recommended rates of two dissimilar herbicides, triallate and difenzoquat. We used exogenous applications of gibberellic acid (GA₃) to investigate the possibility that endogenous gibberellins were involved in the A. fatua 's resistance mechanism. For control plants, without applied GA₃, shoots of the most resistant (R) populations emerged more rapidly and elongated faster than shoots of the susceptible (S) populations. Increases in shoot elongation in response to exogenous GA₃ were significantly lower in R populations compared with S populations. This suggests that R populations may have elevated endogenous gibberellin levels, relative to S populations. Additionally, inhibition of S population shoot elongation and shoot anatomical abnormalities caused by relatively low concentrations of triallate and difenzoquat could be prevented by exogenous application of GA₃. These results suggest that there may be a phytohormonal involvement in the mechanism of triallate/difenzoquat resistance in A. fatua . That is, higher endogenous gibberellin levels in R populations may result in meristematic growth that is rapid enough to preclude phytotoxic levels of these herbicides from reaching the shoot meristem, which is the likely site of action.     

Comparative testing of several juvenile hormone analogues in two species of locusts,Locusta migratoria migratorioides and Schistocerca gregaria

Effective treatment with juvenile hormone analogues (JHAs) of early penultimate or early last-instar locust hoppers induces a supernumerary ‘extra’ nymphal instar. These ‘extra’ nymphs, also termed ‘adultoids’, die in the course of, or shortly after, an ‘extra’ moult. Less effective treatment results in imperfect adults with crumpled twisted wings which presumably limit their flight and migratory abilities. Extremely effective treatment leads to death in the next moult. Comparing dose-response relations of (7S)-methoprene, fenoxycarb, pyriproxyfen and a new JHA, R70-1 (ethyl cis-N-{2-[4-(2-hydroxycyclohept-1-ylmethyl)phenoxy]ethyl}carbamate), we revealed that route of administration, instar of the recipient hopper, and species may alter over 1000-fold the ED₅₀ for the same JHA. Locusta migratoria migratorioides is much more susceptible to JHAs than Schistocerca gregaria. The lowest ED₅₀ found to induce adultoids and subsequent death in the ‘extra’ moult was 0·12 μg pyriproxyfen injected in olive oil to early penultimate instar hoppers of L. m. migratorioides (about 0·5 μg g^-1 fresh weight). R70-1 was more active than pyriproxyfen following the more practical topical application to early last-instar hoppers of L. m. migratorioides, 5·9 μg and 46 μg per hopper, respectively (about 10 μg g^-1 and 78 μg g^-1 fresh weight). The high susceptibility of last-instar L. m. migratorioides nymphs to topically applied R70-1 is promising from the practical standpoint. ©1997 SCI     

Dietary supplementation effects of Pediococcus acidilactici as probiotic on growth performance,digestive enzyme activities and immunity response in zebrafish (Danio rerio)

This study was carried out to assess the effects of Pediococcus acidilactici on zebrafish (Danio rerio). Different levels of P. acidilactici including 0, 1 × 10⁶, 2 × 10⁶, 4 × 10⁶ and 8 × 10⁶ colony‐forming unit per g of the diet (cfug^?1) were examined in fish with 120 ± 10 mg weight for 60 days in a completely randomized design. The results showed that the best growth indices were recorded in group 4 × 10⁶ cfug^?1 (p < 0.05). The highest number of total viable count and lactic acid bacteria of intestine were found in group 4 × 10⁶ cfug^?1 (p < 0.05). The maximum activity of digestive enzymes including amylase, lipase, protease and alkaline phosphatase was observed in group 4 × 10⁶ cfug^?1. The highest activity for superoxide dismutase was recorded in group 4 × 10⁶ cfug^?1 while catalase, glutathione peroxidase and glutathione reductase showed the highest activity in group 8 × 10⁶ cfug^?1. The most growth inhibition zone of Aeromonas hydrophylla, Flavobacterium columnare, Vibrio anguillarum and Edwardsiella tarda was found in group 4 × 10⁶ cfug^‐1 (p < 0.05). Therefore, P. acidilactici as a probiotic improved growth and immunity of the zebrafish and could be used by zebrafish farmers.     

Combined or individual effects of dietary magnesium and selenium nanoparticles on growth performance,immunity, blood biochemistry and antioxidant status of Asian seabass (Lates calcarifer) reared in freshwater

This study was conducted to investigate effects of and interactions between nanoselenium (NanoSe) and nanomagnesium (NanoMg) on growth, humoral immunity, serum biochemistry and antioxidant capacity of juvenile Asian seabass Lates calcarifer reared in freshwater. Four groups of fish with an average weight of 32.78 ± 2.23 g were fed one of the experimental diets for 6 weeks: (a) control (basal diet); (b) NanoSe (basal diet + 4 mg NanoSe/kg diet); (c) NanoMg (basal diet + 500 mg NanoMg/kg diet); and (d) combination (basal diet + 4 mg NanoSe/kg diet + 500 mg NanoMg/kg diet). Fish fed with NanoSe‐supplemented diets (NanoSe and combination) showed higher weight gain, specific growth rate and feed intake. The combination of NanoSe and NanoMg enhanced the immune response. Also, fish fed on combination diet showed higher serum alanine aminotransferase and aspartate transaminase levels but lower glucose concentration. The activities of liver superoxide dismutase, glutathione peroxidase and catalase were not different among all groups, but liver malondialdehyde level was lower in fish fed diets supplemented with NanoSe and/or NanoMg. It could be concluded that NanoSe improved growth performance; the combination of both NanoSe and NanoMg enhanced humoral immunity; and NanoSe and/or NanoMg improved antioxidant capacity in Asian seabass.