Impact of milking characteristics and teat morphology on somatic cell counts in first-lactation Norwegian cattle     

Trond Slettbakk  Asbjrn Jrstad  Thomas B. Farver  David W. Hird 《Preventive veterinary medicine》1990,8(4):253-267

Data from the Norwegian progeny-testing program were used to examine the impact of milking characteristics and teat morphology on log_e somatic cell counts (SCC) in first-lactation Norwegian Cattle. Three primary independent study variables (2-min milk, milk leakage and teat-end-to-floor distance) were evaluated in addition to six other study variables and six potential confounding variables. Seven different regression models were evaluated. Sire and herd were identified as confounding variables. The chosen model was based on 4090 cows in 1993 herds, sired by 119 bulls, and had a coefficient of variation of 0.59. Increased 2-min milk, decreased teat-end-to-floor distance and inverted or pointed teat-end shapes were significantly (P ≤ 0.01) associated with a higher log_e SCC. Effect of herd was absorbed in the model and explained 50% of the total variability in log_e SCC, whereas sire and the total effect the study variables explained < 5% each. Among-herd variability is discussed in relation to the study design.  相似文献   

Parapoxvirus papillomatosis in the muskoxen (Ovibos moschatus): genetical differences between the virus causing new outbreak in a vaccinated herd, the vaccine virus and a local orf virus     

Ugo Moens  Inger Wold  Svein D. Mathiesen  Trond Jorgensen  Dag Srensen  Terje Traavik 《Acta veterinaria Scandinavica》1990,31(1):17-25

Since 1981 a domesticated muskoxen herd had been successfully vaccinated against papillomatosis with homogenated, glutaraldehyde inactivated papilloma tissue. In the fall of 1985 a new clinical outbreak of disease occurred, affecting previously infected as well as vaccinated animals. The purification of parapox virions directly from papilloma tissue and orf scabs collected in a local sheep farm was followed by restriction endonuclease analysis of viral DNA. The morphological identity of purified virus was controlled by electron microscopy. Comparison of restriction endonuclease digests (10 different enzymes) by gel electrophoresis demonstrated that the muskoxen parapoxvirus from the new outbreak 1985 differed considerably from the 2 other isolates (muskoxen 1981 and local orf). The latter viruses demonstrated a high degree of homology, but differences were evident after digestion with the enzyme EcoRI. During metrizamide gradient purification minor bands containing morphologically intact virions were isolated in addition to the major fractions. The restriction enzyme digests indicated that the virions of the minor bands differed from those in the major bands.  相似文献   

The competitiveness of the Chilean salmon aquaculture industry     

Trond Bjørndal 《Aquaculture Economics & Management (Blackwell Science)》2013,17(1-2):97-116

Abstract

Commercial salmon and trout farming has emerged as a major industry in Chile during the 1990s. Salmon is not a native species to Chile, still excellent climatic conditions are provided for farming. Since 1992 Chile has been the second largest producer of farmed salmon and trout in the world after Norway. This report reviews the development of the Chilean salmonid industry from its early stages until today with respect to production patterns, legislation and main markets. A cost comparison between Chilean and Norwegian farmed salmon is also provided. Finally, the international competitiveness and future challenges of the Chilean salmonid farming industry are analysed.  相似文献   

Economic analysis of land based farming of salmon     

Trond Bjørndal  Amalie Tusvik 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):449-475

Abstract

Land-based farming of salmon is emerging for a number of reasons. The demand for salmon is increasing in many parts of the world. In recent years there has been limited growth in production due to binding government regulations and environmental challenges in sea-based salmon aquaculture. This is true both for Norway (sea lice, salmon escapes) and Chile (sea lice, disease problems), the two largest producers of salmon. Growing demand and limited expansion in production have made for a very profitable industry. At the same time, there have been technological developments when it comes to land-based farming (a technology used for smolt production and species such as sole and turbot), and cost of production has changed. Currently, land-based salmon farming is in operation or in development in several countries including the USA, Denmark, and Norway. In this paper, the economics of land-based salmon farming in a Norwegian context is presented, with an emphasis on the relative competitiveness of this vis-à-vis sea-based farming. If successful, land-based farming could potentially have an important impact on the dynamics of the salmon market.  相似文献   

Violacein-Producing Collimonas sp. from the Sea Surface Microlayer of Costal Waters in Tr?ndelag,Norway     

Sigrid Hakv?g  Espen Fj?rvik  Geir Klinkenberg  Sven Even F. Borgos  Kjell D. Josefsen  Trond E. Ellingsen  Sergey B. Zotchev 《Marine drugs》2009,7(4):576-588

A new strain belonging to the genus Collimonas was isolated from the sea surface microlayer off the coast of Trøndelag, Norway. The bacterium, designated Collimonas CT, produced an antibacterial compound active against Micrococcus luteus. Subsequent studies using LC-MS identified this antibacterial compound as violacein, known to be produced by several marine-derived bacteria. Fragments of the violacein biosynthesis genes vioA and vioB were amplified by PCR from the Collimonas CT genome and sequenced. Phylogenetic analysis of these sequences demonstrated close relatedness of the Collimonas CT violacein biosynthetic gene cluster to those in Janthinobacterium lividum and Duganella sp., suggesting relatively recent horizontal gene transfer. Considering diverse biological activities of violacein, Collimonas CT shall be further studied as a potential producer of this compound.  相似文献   

Susceptibility of Salmonella isolated from fish feed factories to disinfectants and air-drying at surfaces     

Møretrø T  Midtgaard ES  Nesse LL  Langsrud S 《Veterinary microbiology》2003,94(3):207-217

The objective of this work was to determine whether persistence of certain Salmonella isolates in fish feed factories involved enhanced resistance to disinfectants or air-drying. Salmonella isolates known to be persistent in fish feed factories and Salmonella isolates from other origins were tested for their sensitivity to nine disinfectants by using a suspension test. More than 5log(10)reduction in viable count for all isolates was only achieved by two of the disinfectants at 80% of the lowest recommended user concentration. However, Salmonella isolates from fish feed factories were not more resistant to disinfectants compared to Salmonella from other origins. For four of the disinfectants, presence of fish feed had a more adverse effect on disinfection efficacy compared to the protein bovine serum albumin (BSA). In general, the Salmonella isolates were more resistant to disinfection than Escherichia coli DSM 682, a strain recommended in testing of disinfectants. The Salmonella isolates were also tested for their ability to survive air-drying at stainless steel surfaces, but there were no differences in survival of isolates from fish feed factories compared to isolates of other origin. In conclusion the Salmonella isolates from fish feed factories were not particularly resistant to disinfection or air-drying at surfaces. The data show that disinfectants to be used against Salmonella should be thoroughly tested and selected, since not all disinfectants appear to be effective against Salmonella.  相似文献   

Effect of fertilization rate and ploughing time on nitrous oxide emissions in a long-term cereal trail in south east Norway     

Shahid Nadeem  Trond Børresen  Peter Dörsch 《Biology and Fertility of Soils》2015,51(3):353-365

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Nutrient digestibilities and gut function in Atlantic salmon (Salmo salar) fed diets with cellulose or non-starch polysaccharides from soy     

Olav Fjeld Kraugerud  Michael Penn  Trond Storebakken  Ståle Refstie  Åshild Krogdahl  Birger Svihus 《Aquaculture (Amsterdam, Netherlands)》2007,273(1):96-107

Duplicate groups of Atlantic salmon (Salmo salar), kept in saltwater, were fed fish meal based cold-pelleted diets where graded levels of native or extruded non-starch polysaccharides (NSP) from soybeans replaced cellulose, at a total NSP level of 100 g kg^− 1 for 28 days. The study also included a diet where defatted soybean meal (SBM) constituted the NSP at a level of 100 g kg^− 1 and a reference diet without NSP supplementation.The SBM diet resulted in a significant reduction in faecal dry matter content, apparent digestibilities of starch and organic material, and growth, and an increased faecal output of several elements (K, Na, Zn), compared to all the other diets. Morphological changes were only seen in the intestine of the fish fed the SBM, i.e. the diets holding purified soy-NSP did not induce enteritis. When compared to the diet without NSP, cellulose addition increased faecal dry matter, while inclusion of native soy-NSP reduced it. Dry matter in faeces and apparent digestibility of crude protein decreased in a linear manner, while the digestibility of starch and faecal output of K and Na increased linearly when native soy-NSP replaced graded levels of cellulose from 0 to 100 g kg^− 1 feed. When diets with 75 or 100 g kg^− 1 of native NSP and extruded soy-NSP were compared, fish fed native soy-NSP had reduced faecal dry matter, higher digestibility of starch, and increased faecal output of Cu, Fe, and K. Dry matter in faeces and faecal output of Cu was lower for the highest inclusion level, while digestibility of starch and faecal output of Mn and K were higher.In conclusion, soy-NSP was inert compared to the fish meal reference, with respect to nutrient digestibilities and intestinal pathologies, but affected faecal mineral excretion in Atlantic salmon.  相似文献   

Carotenoids in diets for salmonids: II. Epimerization studies with astaxanthin in Atlantic salmon     

Trond Storebakken  Per Foss  Erland Austreng  Synnøve Liaaen-Jensen 《Aquaculture (Amsterdam, Netherlands)》1985,44(4):259-269

Atlantic salmon (Salmo salar, L.), kept in sea pens were fed diets containing pure carotenoids. No significant preferential utilization of the (3S,3′S), (3R,3′S) or (3R,3′R) optical isomers of astaxanthin was observed. No epimerization occurred in the flesh at the chiral centres at C-3 and C-3′ in astaxanthin.  相似文献   

The significance of various environmental parameters for growth of the Iceland scallop, Chlamys islandica (Pectinidae), in hanging culture     

Jeff C. Wallace  Trond G. Reinsnes 《Aquaculture (Amsterdam, Netherlands)》1985,44(3):229-242

Iceland scallops, Chlamys islandica (O.F. Müller), were grown in hanging culture at 3 different depths (2, 12 and 40 m below the sea surface) in a northern Norwegian fjord. The growth of the soft parts of the body and the shell increment were monitored throughout the growing season (March until September). At the same time, temperature, salinity, water density, current speed, chlorophyll, particulate organic matter (POM) and particulate inorganic matter (PIM) were monitored at each of the experimental depths. Analysis of the environmental data together with the growth data showed that growth differences between the experimental depths were essentially the results of differences in nutritional conditions for the scallops, defined by the relationship between PIM and POM in the water column. The results also showed that growth in Iceland scallops can be increased significantly by suspending the animals in a more favourable nutritional environment than that found on the natural scallop beds.  相似文献