Artenspektrum und Befallshäufigkeit von Fusarium spp. in Bt- und konventionellem Mais im Maiszünsler-Befallsgebiet Oderbruch

The European corn borer (Ostrinia nubilalis) is one of the most important pests of maize (Zea mays). Injuries to the plants caused by the larvae of the European corn borer may represent entrance gates for fungal-spores. The cultivation of Bacillus thuringiensis maize (Bt-maize) is one possibility to reduce infestation by the European corn borer. The aim of the present project was to determine and to compare the number of species and the frequency of Fusarium spp. infestation in Bt-maize (cry1Ab) and conventional maize. In 2003, we analysed the Fusarium spp. infestation of samples of chaffed Bt-maize and its isogenic variety on two experimental fields in the Oderbruch region (Germany), an European corn borer infested area. The conventional variety on the first of the experimental fields (previous crop wheat and forking cultivation) showed a small infestation (16%) of Ostrinia nubilalis while in the conventional variety on the second field (previous crop maize and not forking cultivation) the infestation of the European corn borer was almost three times higher (47%). In the conventional variety on both of the experimental fields we found a high Fusarium spp. infestation (70%). Especially species of the section Liseola dominates, among them: F. subglutinans, F. proliferatum und F. verticillioides. The Fusarium infestation in the samples of Bt-maize from the field with previous crop wheat and forking cultivation was just as high as in the conventional variety (70%). The infestation of Fusarium spp. in the samples of Bt-maize from the field with previous crop maize and forking cultivation was more than 20?% lower.     

Comparative survival and growth performance of European lobster Homarus gammarus post‐larva reared on novel feeds

One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by‐products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post‐larval lobsters from post‐larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze‐dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven‐dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring‐based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non‐heat‐treated shrimp products are a promising feed ingredient for post‐larval European lobsters.     

The opioid haemorphin-7 in horses during low-speed and high-speed treadmill exercise to fatigue

The opioid neuropeptide haemorphin-7 was measured, by immunoreactivity, in Standardbred horses during low-speed (7 m/s) and high-speed (10 m/s) endurance exercises, lasting 49-58 and 12-16 min respectively. In parallel, heart rate, muscle temperature and plasma lactate concentrations were measured. The profile of the low-speed exercise showed significantly increased heart rate after 10 min [154 beats per minute (bpm)]. After the exercise, muscle temperature (42.1 degrees C) and plasma lactate (4.8 mmol/l) were significantly increased. The profile of the high-speed exercise was comparatively characterized by a higher increase of heart rate after 5 min (194 bpm) and higher increases of muscle temperature (43.2 degrees C) and lactate levels (15.8 mmol/l) after the exercise. The horses were probably exhausted by glycogen depletion in the low-speed exercise and by muscle pH decrease in the high-speed exercise. Haemorphin-7 increased significantly during the high-speed exercise (274.8 fmol/ml) but not during low speed (108.3 fmol/ml), coincident with the results of lactate. These results suggest that plasma haemorphin-7 is measurable in the horse by immunoreactivity, and that intense exercise stimulates release of this opioid. Such endogenous opioids are most likely involved in regulatory functions associated with pain, physical effort, inflammation, and blood pressure variation in horses, as have been established in other species.     

Circulatory and muscle metabolic responses to draught work compared to increasing trotting velocities

Circulatory and muscle metabolic responses were studied in 10 horses which all performed incremental draught work at a low trotting speed on a treadmill (D-test) and also exercise with gradually increasing velocities (S-test). Exercise was continued until the horses could no longer maintain the weights above the floor or maintain speed trotting without changing gait to a gallop. Muscle biopsies were taken from the gluteus and the semitendinosus muscles before, and immediately after, exercise. The heart rate (HR) increased linearly with both increasing draught resistance and velocity and reached mean values of 212 and 203 beats/min, respectively. Blood lactate levels increased exponentially to mean values of 12.9 and 7.9 mmol/litre in the two tests. Both HR and blood lactate levels were significantly higher at the cessation of work in the D-test compared to the S-test. The relationship between HR and blood lactate response in the S-test was similar to that in the D-test. The red cell volume was determined after a standardised exercise tolerance test and was significantly correlated both to the weightloading and to the velocity, producing a HR of 200 beats/min. The changes seen in muscle glycogen and glucose-6-phosphate were similar in the two tests, whereas significantly higher lactate levels and lower creatine phosphate and adenosine triphosphate levels were seen in the D-test compared to the S-test. It was concluded that high oxidative capacity is of importance both for fast trotting and for draught work.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hypophosphatemia induced by dietary aluminium hydroxide supplementation in pigs: effects on growth, blood variables, organ weights and renal morphology

Twenty-four pigs, 13-14 weeks of age, were studied during an experimental period of 10 weeks. The pigs were randomly divided into 3 groups. Two groups were fed a commercial feed supplemented either with a suspension of aluminium hydroxide (Al(OH)₃) or aluminium phosphate (A1PO₄). The third group served as a control. The same total amount of aluminium was given to each of the 2 experimental groups. After three weeks the Al(OH)₃-pigs developed severe hypophosphatemia, with an average decrease in serum phosphate of 60%, a decreased growth rate and a lower concentration of 2,3-diphosphoglycerate in the erythrocytes as compared to controls. Intense hypercalcemia developed in the Al(OH)₃-group during the first 6 weeks, whereas the AlPO₄-pigs and the control group developed neither hypophosphatemia nor hypercalcemia. At necropsy, the consequence of the long lasting hypophosphatemia was found to be increased relative kidney weights with morphological signs of tubular damage and dyscalcification. No similar changes were observed in the AlPO₄-groups and there were no organ weight deviations compared to the control group.     

Hypophosphatemia Induced by Dietary Aluminium Hydroxide Supplementation in Growing Pigs: Effects on Erythrocytes,Myocardium, Skeletal Muscle and Liver

Håglin, L., B. Essén-Gustavsson and A. Lindholm: Hypophosphatemia induced by dietary aluminium hydroxide supplementation in growing pigs: Effects on erythrocytes, myocardium, skeletal muscle and liver. Acta vet. scand. 1994, 35, 263-271.– Three groups of pigs were studied during and after 10 weeks of treatment with either Al(OH)₃ (Al[OH]₃-group, n=8) to induce hypophosphatemia, A1P0₄ (AlP0₄-group, n=8, aluminium control without hypophosphatemia) or no addition to the feed (control group, n=8). Blood samples were taken at the start of the experiment and after 3, 6 and 10 weeks and were analyzed for phosphate, calcium and 2,3-diphosphoglycerate (2,3-DPG). Samples from myocardium, skeletal muscle and liver were obtained in connection with exsanguination and analyzed for glycogen, adenosine-tri-phosphate (ATP), creatine phosphate (CP), glucose-6-phosphate (G-6-P) and lactate. The Al(OH)₃-group became hypophosphatemic and hypercalcémie with low levels of 2,3-DPG in erythrocytes within 3 weeks and showed a retarded growth rate. After 10 weeks the Al(OH)₃-group had low levels of ATP in myocardium as compared with the control-group and low levels of G-6-P as compared with the AlP0₄-group. No disturbances on electro-cardiograms registered at rest could be documented. G-6-P concentration was low in the biceps muscle in the Al(OH)₃-group as compared with the AlP0₄-group and in the liver low G-6-P concentration was seen in addition to high lactate concentration. The fibre type composition in M. Longissimus did not differ between groups, but the Al(OH)₃-group had, due to retardation in growth, smaller mean fibre-areas than pigs in the AlP0₄-group. Hypophosphatemia gave rise to high serum calcium levels, low concentration of 2,3-DPG in erythrocytes and influenced G-6-P concentration in skeletal muscle, G-6-P and ATP in myocardium, G-6-P and lactate in liver. Retarded growth was one serious consequence of hypophosphatemia and the disturbed energy metabolism.     

Application of two-dimensional gel electrophoresis to interrogate alterations in the proteome of genetically modified crops. 1. Assessing analytical validation

Current tools used to assess the safety of food and feed derived from modern biotechnology emphasize the investigation of possible unintended effects caused directly by the expression of transgenes or indirectly by pleiotropy. These tools include extensive multisite and multiyear agronomic evaluations, compositional analyses, animal nutrition, and classical toxicology evaluations. Because analytical technologies are rapidly developing, proteome analysis based on two-dimensional gel electrophoresis (2DE) was investigated as a complementary tool to the existing technologies. A 2DE method was established for the qualitative and quantitative analysis of the seed proteome of Arabidopsis thaliana with the following validation parameters examined: (1) source and scope of variation; (2) repeatability; (3) sensitivity; and (4) linearity of the method. The 2DE method resolves proteins with isoelectric points between 4 and 9 and molecular masses (MM) of 6-120 kDa and is sensitive enough to detect protein levels in the low nanogram range. The separation of the proteins was demonstrated to be very reliable with relative position variations of 1.7 and 1.1% for the pI and MM directions, respectively. The mean coefficient of variation of 254 matched spot qualities was found to be 24.8% for the gel-to-gel and 26% for the overall variability. A linear relationship (R2 > 0.9) between protein amount and spot volume was demonstrated over a 100-fold range for the majority of selected proteins. Therefore, this method could be used to interrogate proteome alterations such as a novel protein, fusion protein, or any other change that affects molecular mass, isoelectric point, and/or quantity of a protein.     

Carbon isotope constraints on the deglacial CO₂ rise from ice cores

The stable carbon isotope ratio of atmospheric CO(2) (δ(13)C(atm)) is a key parameter in deciphering past carbon cycle changes. Here we present δ(13)C(atm) data for the past 24,000 years derived from three independent records from two Antarctic ice cores. We conclude that a pronounced 0.3 per mil decrease in δ(13)C(atm) during the early deglaciation can be best explained by upwelling of old, carbon-enriched waters in the Southern Ocean. Later in the deglaciation, regrowth of the terrestrial biosphere, changes in sea surface temperature, and ocean circulation governed the δ(13)C(atm) evolution. During the Last Glacial Maximum, δ(13)C(atm) and atmospheric CO(2) concentration were essentially constant, which suggests that the carbon cycle was in dynamic equilibrium and that the net transfer of carbon to the deep ocean had occurred before then.