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The aim of this study was to investigate the effect of prehandling stress on the flesh quality of Atlantic cod (Gadus morhua). In order to stress the animal, water was reduced in the tank before a total of 30 fish were caught five at a time using a dipnet and held for 3 min, causing stress by hypoxia. This fish was compared with a control group (n=30) of fish exposed to anaesthetics directly in the tank. All fish were killed by a percussive blow to the head and exsanguinated and stored on ice before flesh quality was measured. Immediately after death and after ice storage for 3 and 8 days, 10 fish per group were measured for muscle pH, texture, fillet gaping, colour, drip loss and cathepsin D. Handling stress resulted in an initial increased fillet lightness, drip loss and decreased fillet shear force, although these differences did level off during ice storage. Stress caused by handling resulted in earlier onset of rigour mortis as compared with the control group, which reached maximum rigour tensions within 26 and 36 h postmortem respectively. We conclude that handling before harvest results in reduced time before entering rigour. After 8 days of ice storage, no effect of handling stress was seen on the muscle pH, flesh colour, fillet shear force, gaping score, drip loss or cathepsin D activity. 相似文献
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Two methods for the determination of DNA have been adapted for use on the bacterial fraction of an organic soil, obtained by fractionated centrifugation. The. soil contained about 1.1 × 1010 bacteria g?1 dry weight when counted by fluorescence microscopy. One method was based on the reaction with 3,5-diaminobenzoic acid 2HCl, and the other on the specific reaction of the antibiotic mithramycin with double-stranded DNA. For the first method, about 8 × 108 cells were required and for the second, about 4 × 109. The analytical results with the two methods agreed well. As an average of several determinations, an amount of 8.4 fg (10?15g) DNA per bacterial cell was found when the cells were counted by fluorescence microscopy. This is in the upper size range of bacterial genomes. showing that virtually all microscopically counted bacteria in this soil contain DNA. The total amount of DNA was about 90μg g?1 soil dry weight. 相似文献
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The impact of nutrition on metamorphosis in Atlantic halibut (Hippoglossus hippoglossus L.) 总被引：1，自引：0，他引：1
Kristin Hamre Mari Moren Jostein Solbakken Ingegjerd Opstad Karin Pittman 《Aquaculture (Amsterdam, Netherlands)》2005,250(3-4):555-565
Fatty acids, vitamin A and thyroid hormone have all been shown to affect development of flatfish larvae and they are ligands to nuclear receptors that participate in the control of development. Our hypothesis was that one of these factors or an interaction between them may be the cause of abnormal development of flatfish larvae. Atlantic halibut larvae were fed either DHA-selco-enriched Artemia or copepods from first feeding. In fish that had been fed Artemia, only 7% had normal pigmentation and 10% normal eye migration. The numbers for fish fed copepods were 68% and 88%, respectively. Malpigmented fish fed Artemia were depigmented, while those fed copepods had ambicoloration. The differences in development were probably nutrient dependent, since all other conditions were similar for the two groups. Larvae fed copepods had markedly higher body levels of docosahexanoic acid (DHA, 22:6n−3) and eicosapentaenoic acid (EPA, 20:5n−3) and lower levels of arachidonic acid (ARA, 20:4 n−6) than larvae fed Artemia. The DHA/EPA ratio was similar in the two groups, but the EPA/ARA ratio was more than four times higher in larvae fed copepods than in larvae fed Artemia. Larvae fed copepods had higher body levels of total retinol than larvae fed Artemia, but the difference was due to higher levels of the storage forms, retinyl esters, whereas the levels of free retinol and retinal were similar in the two groups. The level of iodine was 700 times higher in copepods than in Artemia and 3–4 times higher in larvae fed copepods than in larvae fed Artemia. There was a significantly higher level of T4 in larvae fed copepods during the “window of opportunity”, 15–30 days after first feeding. In an experiment where Atlantic halibut larvae were fed Artemia enriched in iodine up to the levels found in copepods, there was a significant effect on the body level of iodine and a non-significant tendency of higher levels of thyroid hormone, but no effect on pigmentation or eye migration. It is concluded that Artemia probably offers a sufficient access to vitamin A precursors to meet the larval requirement. More research should be done to elucidate possible effects of iodine on development of Atlantic halibut larvae. Fatty acid composition is still the most likely candidate for causing abnormal development in Atlantic halibut larvae. 相似文献
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Jostein Larsen DVM PhD Jan Fredrik Brseth Cand. Real David Weckner DVM 《Journal of Equine Veterinary Science》1996,16(11):498-501
This study was conducted to investigate the relationships between the concentrations of potassium, sodium, calcium and magnesium of plasma and muscle in horses, as interactions between these ions can be important in the development of muscle cell injury. Blood samples and gluteal muscle biopsies were taken from 20 healthy Standardbreds to determine the potassium concentration in plasma (cK+(P)), red blood cells (cK+(RBC)), and muscle (cK+(M)), and the calcium and magnesium concentrations in plasma and muscle. No correlations were found between cK+(P), cK+(RBC), and cK+(M). Significant positive correlations were found between cK+(M) and muscle magnesium (p<0.01); and cK+(P) and plasma calcium (p<0.005). Significant negative correlations were found between cK+(M) and the percentage of muscle water (p<0.005); and the muscle magnesium and calcium concentrations (p<0.02). 相似文献
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. Sle J. S. Solbakken K. Watanabe K. Hamre K. Pittman 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):683-696
Larval nutrition affects post-metamorphic phenotype in Atlantic halibut and many deformities are related to skeletal development. In a multidisciplinary study, 24,000 sibling halibut larvae were reared at an average temperature of 11.9 °C on either enriched Artemia or natural zooplankton in duplicate treatments and the development followed. One hundred and eighty sibling larvae up to about climax metamorphosis at 46 days post start feeding (psf) were cleared and stained for bone, and stereological measurements of bone and body area and degree of eye migration were registered. From day 21 psf, the zooplankton-fed fish had more calcified matrix relative to body size than did Artemia-fed halibut and from day 35 psf, this difference was significant (33.7%±1.9 SD vs. 28.6%±4.1, P<0.05). When related to ontogeny, the zooplankton-fed fish had a higher average percentage ossification than the Artemia-fed larvae at Stages 7, 8 and 9 (pro- and climax metamorphosis), but this difference was significant only at Stage 8 (34.1%±2.56 SD vs. 31.9%±2.32 SD, P<0.05). Asymmetry of the cranium and consequently eye migration began earlier (Stage 7 vs. Stage 9) and was significantly better in the zooplankton-fed fish. The results suggest that nutritional differences in content of vitamin A and thyroid hormones, which target osteoblasts and osteoclasts, may underlie differences in developmental trajectory. The results also support the hypothesis of a critical window of metamorphosis between 14 and 25 days post start feeding in halibut larvae. 相似文献
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The present prospective study included 106 horses referred to the Department of Large Animal Sciences, The Norwegian School of Veterinary Science, as non-responders to the initial colic treatment in general practise. In 14 of these cases a required surgical treatment was not performed due to economical or other reasons and were excluded from the study. Clinical and laboratory data were obtained at the arrival in the hospital. The outcome for all analyses was survival/ non-survival. A multivariable logistic regression was performed. The analyses were used in medically (46 horses) and surgically treated cases (46 horses) separately. The same analyses were also run for all 92 horses in a simulated "field" situation, where only clinical variables and D-dimer values were included. The fraction of survivors was 78% in the medical and 48% in the surgical cases. In total 63% of the horses survived. In the final multivariable logistic regression model packed cell volume (PCV) was the only important predictor for medically treated cases, and heart rate and presence of hyperaemic or cyanotic mucous membranes were the predictors in the surgically treated cases as well as in the simulated "field" situation. In conclusion, traditional variables as heart rate, mucous membranes and PCV were the important predictors for the outcome in hospitalised colic cases. 相似文献
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