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1.
Håkon Otterå Oddvard Garatun-Tjeldstø Kåre Julshamn Erland Austreng 《Aquaculture International》2003,11(1-2):217-224
There are indications that low ingestion ratesof formulated feed may limit the growth ofearly juvenile fish, including cod. This hasparticularly been observed during the weaningperiod, when the fish must change from apresumably palatable live prey to usually a drydiet. The study of the physical properties ofthe diet seems to be an underestimated area ofresearch, compared to studies on thenutritional properties of the diet. In thisstudy we used lanthanide markers as a tool inestimating diet preferences for examining theeffect of dietary moisture content on ingestionrates in juvenile cod (0.8 g). Fishmeal-baseddiets were produced with five levels of water,giving diets with 35, 42, 54, 65 or 95% dryweight. Each diet was marked with a smallamount of a lanthanide or yttrium oxide. Thefish were hand fed on a mixture of these fivediets. Ingestion rates where then estimated bykilling 1/2 of the fish after one day and therest after four days of feeding. The whole fishwith gut content was homogenized and markercontent was measured by ICP-MS. The amountingested of each of the five diets could thenbe calculated from these figures. Despite thehigh variation in diet selection betweenindividuals the results clearly indicate ahigher intake of moist feed. This could becaused by a better palatability or to a higheravailability caused by a lower sinking rate ofthe moist feed. 相似文献
2.
A. F. A. El-Mowafi A. Maage M. Lorentzen E. I. Hassanein & K. Julshamn 《Aquaculture Nutrition》1997,3(2):73-80
Two groups of Atlantic salmon post-smolts previously fed diets either unsupplemented or supplemented with Zn, Fe, Cu and Mn were fasted for 6 weeks in order to study the reliability of tissue indicators of element status during fasting. The fish were weighed at 2-week intervals and samples of whole fish liver, vertebrae, serum and eyes were taken for analyses of elements by atomic absorption spectrometry.
Body weight, per cent dry matter, condition factor and haematocrit values decreased during the fasting period. The concentration of elements in whole body remained constant, indicating that whole body is a stable indicator of element status during fasting. Other tissues seemed to be more sensitive (i.e. hepatic Fe concentration and vertebrae Zn and Mn concentrations). The serum concentrations of the elements generally decreased during fasting, especially for P and Zn. Element concentrations in whole body and most tissues during fasting were generally more dependent upon initial element status than on the fasting itself.
Care should be taken in drawing conclusions about the element status of fish based solely upon the examination of serum concentrations, and more than one tissue indicator should be used in the establishment of the element status of fish. 相似文献
Body weight, per cent dry matter, condition factor and haematocrit values decreased during the fasting period. The concentration of elements in whole body remained constant, indicating that whole body is a stable indicator of element status during fasting. Other tissues seemed to be more sensitive (i.e. hepatic Fe concentration and vertebrae Zn and Mn concentrations). The serum concentrations of the elements generally decreased during fasting, especially for P and Zn. Element concentrations in whole body and most tissues during fasting were generally more dependent upon initial element status than on the fasting itself.
Care should be taken in drawing conclusions about the element status of fish based solely upon the examination of serum concentrations, and more than one tissue indicator should be used in the establishment of the element status of fish. 相似文献
3.
Supplementing copper to a fish meal based diet fed to Atlantic salmon parr affects liver copper and selenium concentrations 总被引：1，自引：0，他引：1
The present experiment was conducted to study growth and tissue responses in Atlantic salmon, Salmo salar L., fed a fish meal based diet supplemented with copper (Cu). The findings of the experiment were used to evaluate the need for dietary Cu supplementation. Atlantic salmon parr, initially weighing ≊ 7.5 g, were randomly distributed among 10 tanks, with 300 fish in each tank. Duplicate groups of fish were fed a fish meal based diet containing 3.5 mg Cu kg−1 , or this diet supplemented with 5, 10, 50 or 100 mg Cu kg−1 (as CuSO4 *5 H2 O) for 12 weeks. Growth was recorded and blood haemoglobin measured. The Cu concentrations in whole body, liver, serum and selected muscle samples were measured, as was liver selenium (Se) concentration.
There were no difference in growth among the dietary treatments. There were, however, significant differences among the dietary groups in liver Cu and Se concentrations. The fish fed the diet supplemented with 5 mg Cu kg−1 had increased liver Cu concentration compared with the other groups. Similar trends were found for serum Cu concentration and whole-body Cu concentration, but these effects were not significant. Liver Cu and Se concentrations were positively correlated and liver Se concentrations were inversely correlated to dietary Cu concentration, confirming an interaction between these two elements in salmon.
There may be a positive effect of a modest Cu supplementation level, and we suggest that a small amount of Cu (5–10 mg kg−1 ) should be added to fish meal based diets. 相似文献
There were no difference in growth among the dietary treatments. There were, however, significant differences among the dietary groups in liver Cu and Se concentrations. The fish fed the diet supplemented with 5 mg Cu kg
There may be a positive effect of a modest Cu supplementation level, and we suggest that a small amount of Cu (5–10 mg kg
4.
M. K. Malde I. E. Graff H. Siljander‐Rasi E. Venäläinen K. Julshamn J. I. Pedersen J. Valaja 《Journal of animal physiology and animal nutrition》2010,94(5):e66-e76
In general, there is a lack of scientific documentation of nutritional value of marine by‐products. The bone fraction from fish has been regarded as waste. Due to the high mineral content of fish bones, this material can be well suitable as a natural calcium source. In the present study, apparent calcium absorption of different fish bone sources was tested using growing pigs. The experimental diets consisted of boiled salmon frames, or salmon, saithe or cod bones treated with enzymes. Calcium carbonate (CaCO3) was used as control. The experimental diets were formulated to contain 0.7% total calcium of which the added calcium source to be tested contributed about 71% (study 1) and 86% (study 2). Except for the calcium and phosphorus sources, the animals received similar basal diets. Apparent calcium digestibility coefficient was calculated using yttrium as indicator (both studies) and was based on complete collection of faeces and urine (study 2). The experimental design was parallel and cross‐over in study 1 and study 2, respectively. In study 1, piglets getting salmon bone treated with enzymes had significantly higher calcium absorption than piglets getting boiled fish bone or calcium carbonate. Therefore, in the second study only enzymatically treated fish bones were included. The higher calcium absorption from enzymatically treated salmon bone was also found in study 2, but this time not significant. Calcium from boiled salmon bones in study I, and from enzymatically treated saithe and cod bones in study II were absorbed as well as the calcium carbonate control. The results indicate that fish bones may be a useful and well absorbed calcium source. Due to the high mineral content of the bone fraction, salmon bones can be well suitable as a natural calcium and phosphorus source in, for example, food, feed or as supplement. 相似文献
5.
N.H. Sissener K. Julshamn M. Espe B.T. Lunestad G.‐I. Hemre R. Waagb A. Mge 《Aquaculture Nutrition》2013,19(4):555-572
This article presents data on commercial, Norwegian fish feeds from 2000 to 2010, including elements, additives, some selected vitamins and a range of environmental contaminants. Iodine, selenium and vitamin D concentrations, all declined during the time period; simultaneously, a reduction in marine ingredients in feeds has occurred. Still, the feeds fulfilled known fish nutrient requirements. Arsenic (As) in the feed was fitted with a polynomial regression with peak concentrations in 2004, correlating with fishery landings of blue whiting (Micromesistus poutassou), a reduction species with high content of As. A polynomial regression was also significant for mercury, which peaked in 2005 and was correlated to fish meal (FM) inclusion in the feeds. Residues of the pesticide DDT and its metabolites, chlordane and toxaphene, as well as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers and sum dioxins and dioxin‐like PCBs, all decreased during this time period. These positive changes in undesirable substances can likely be attributed to the increasing replacement of marine ingredients with plant ingredients, as well as the increased use of South American fish oils rather than North Atlantic ones. On the other hand, cadmium concentrations were twofold higher in South American FMs, and increased in feeds from 2000 to 2010. 相似文献
6.
The microbiota of pigs influenced by diet texture and severity of Lawsonia intracellularis infection
Mølbak L Johnsen K Boye M Jensen TK Johansen M Møller K Leser TD 《Veterinary microbiology》2008,128(1-2):96-107
Pigs with and without naturally occurring Lawsonia intracellularis infection were fed diets with different texture. In a previous study from 79 pig herds using a similar feeding on pelleted or non-pelleted form showed that the non-pelleted diet was associated with a reduced prevalence of L. intracellularis. In this study a mechanistic approach was taken for explaining and testing this observation by studying the microbiota and the occurrence of L. intracellularis in the distal ileum of 54 pigs by terminal restriction fragment length polymorphism (T-RFLP) analysis, Real-Time PCR and in situ hybridization. The texture of the diet influenced the microbiota, and from a quantitative discriminative analysis of the terminal restriction fragments (T-RFs) of ileum samples it was deduced that Clostridium spp. and Lactobacillus spp. were associated with the non-pelleted diet and Streptococcus spp. with the pelleted diet. In experimentally infected pigs it was verified that 89bp and 90bp sized T-RFs (HhaI) from ileum represented L. intracellularis. The non-pelleted diet seemed to reduce the relative amount of L. intracellularis in the total microbiota of the ileum, but the number of pigs detected positive with L. intracellularis by Real-Time PCR was not influenced. The five pigs with highest L. intracellularis content showed T-RFs that were not present in profiles from less or non-infected pigs, which may indicate that some bacterial species were associated with L. intracellularis infection. 相似文献
7.
OBJECTIVES: To examine dietary iodine sources and to estimate the dietary iodine intake of the Norwegian population. DESIGN: Food iodine analyses carried out in Norway during the last 10 years were compiled, and iodine intake calculated on the basis of food intake data from nation-wide dietary surveys among children and adults. The food intake of adults was measured by a self-administrated food-frequency questionnaire, which covered habitual diet during the past year. The food intake of children was measured by dietary record during four consecutive days. SETTING: Neither household nor industrial iodisation of salt is mandatory in Norway, but some brands of table salt have 5 microg of iodine added per gram of NaCl. In spite of this, the population has been considered iodine-replete for decades, i.e. having an iodine intake well above the Recommended Dietary Allowance of 150 microg day(-1). This assumption has not been substantiated by dietary surveys. SUBJECTS: The adults included 1374 females and 1298 males aged 16-79 years. The children included 185 girls and 206 boys aged 4 years, 411 girls and 404 boys aged 9 years, and 517 girls and 492 boys aged 13 years. RESULTS: The calculated iodine intake was in the range of 100-250 microg day(-1) in the majority of the adult population. The mean iodine intake was 136 microg day(-1) (170 microg I/10 MJ) among women and 176 microg day(-1) (161 microg I/10 MJ) among men. For children the iodine intake was in the range of 100-120 microg day(-1). Milk and dairy products contributed approximately 55% and 70% of the dietary iodine intake in adults and children, respectively. Fish contributed more than 20% of the iodine intake in adults and about 10% in children. The iodine contribution of drinking water was negligible. CONCLUSIONS: While fish has the highest natural concentration of iodine and as such is an excellent iodine source, milk and diary products are the main determinants of iodine intake in the Norwegian population. Iodisation of cow fodder has been mandatory in Norway since 1950 and provides an efficient alternative to universal salt iodisation. Our results show that the dietary iodine intake of adults is in the range considered to be sufficient. The dietary intake of iodine was at recommended levels among the youngest children; however, it decreased among adolescents, especially among girls. 相似文献
8.
A method for the determination of inorganic arsenic in seafood samples using high-performance liquid chromatography-inductively coupled plasma mass spectrometry is described. The principle of the method relied on microwave-assisted alkaline dissolution of the sample, which at the same time oxidized arsenite [As(III)] to arsenate [As(V)], whereby inorganic arsenic could be determined as the single species As(V). Anion exchange chromatography using isocratic elution with aqueous ammonium carbonate as the mobile phase was used for the separation of As(V) from other coextracted organoarsenic compounds, including arsenobetaine. The stability of organoarsenic compounds during the sample pretreatment was investigated, and no degradation/conversion to inorganic arsenic was detected. The method was employed for the determination of inorganic arsenic in a variety of seafood samples including fish, crustaceans, bivalves, and marine mammals as well as a range of marine certified reference materials, and the results were compared to values published in the literature. For fish and marine mammals, the results were in most cases below the limit of detection. For other sample types, inorganic arsenic concentrations up to 0.060 mg kg(-)(1) were found. In all samples, the inorganic arsenic content constituted less than 1% of the total arsenic content. 相似文献
9.
Kåre Julshamn Marian Kjellevold Malde Kjell Bjorvatn & Per Krogedal 《Aquaculture Nutrition》2004,10(1):9-13
The present experiment was performed to study how fluoride from krill meal enriched muscle, whole fish and bone of adult Atlantic salmon (Salmo salar) reared in sea water. Atlantic salmon (mean weight 0.5 kg) were divided into four triplicate groups and fed a commercial fish meal based diets with 0, 100, 200 and 300 g krill kg?1 feed, respectively, for 12 weeks. The fluoride concentrations in the experimental feeds were analysed to be 18, 132, 235 and 358 mg kg?1, respectively. Growth, mortality and feed efficiency were recorded through the experiment. Fluoride concentration was measured in muscle, whole‐body, and bone initially and after 12 weeks of feeding. The fluoride concentrations in the samples were determined by alkali fusion and fluoride ion‐selective electrode. Growth, mortality and feed efficiency ratio were not affected by the dietary treatments. The results showed that fluoride concentration in muscle, whole body and bone were not affected by the dietary fluoride level. The fluoride concentration in the tissues showed great variation among replicates of the group given the same diet. Fillets of the fish varied between 0.3 and 1.4 mg fluoride kg?1 wet weight, whereas the whole‐body concentration of fluoride varied between 3.3 and 6.1 mg kg?1 wet weight and the fluoride bone concentration varied between 5.8 and 7.2 mg kg?1 fresh weight. These results suggest that Atlantic salmon are highly tolerant of dietary fluoride given as krill meal with concentration of fluoride up to 350 mg kg?1 diet, and that accumulation of fluoride from feeding diets containing krill meal does not lead to tissue accumulation in the fish, at least over a short period of time. 相似文献
10.
Guo Chen Camilla Öhgren Maud Langton Kaare F. Lustrup Magnus Nydén Jan Swenson 《Journal of Cereal Science》2013
Frozen storage of bread has a substantial impact on the dynamics of water and ice in the crumb and crust. In this study, the impact was characterized using wheat bread stored at −18 °C for a long term of ∼4 months. The frozen bread incurred a considerable loss of the crumb water that migrated out and formed ice crystals on the bread surface. Such a moisture decrease underwent more rapidly for the bread stored without intact crust, suggesting the specific role of crust during frozen storage. Moisture also redistributed significantly within the frozen crumb, resulting in an elevated crumb heterogeneity of freezable water. This redistribution of freezable water was accompanied by a progressive recrystallization of the crumb-borne ice crystals, which were measured to grow into bulk sizes using a modified calorimetric procedure for analyzing the crumb samples at their as-frozen states. 相似文献