Controlling tick infestations and diseases in sheep by pour-on formulations of synthetic pyrethroids. A field study

The use of synthetic pyrethroids in pour-on formulations reduced tick infestations and the incidence of tick-associated diseases in lambs more than dipping in organophosphate acaricides. Though the use of pyrethroids did not prevent the lambs from being infected with tick-borne fever (TBF), the incidence of lambs with lameness (tick pyaemia) or lambs suddenly found dead (Pasteurella haemolytica septicaemia), which often are seen in association with TBF, was reduced. The use of pyrethroids for three years did not seem to affect the prevalence of TBF.     

The economics of using artificially dried green crops in milk production

From comprehensive experiments in Denmark, it is found that traditional roughage can be substituted by artifically dried grass (cobs) without any technical changes in the milk produced, but with a reduced labour requirement. With respect to maintaining a high feed utilization wafers are preferable to cobs and cobs to pellets.The future of artificially dried crops depends greatly on the ability of the industry to secure a high and uniform quality of these products. If this is achieved, the dried feeds can substitute a great part of the grain mix (concentrates) without any significant reduction of a typical basic ration of roughage for milk cows. Dried crops can be strongly competitive in certain circumstances, depending on its relative to grain mix.As an alternative for traditional conservation methods of grassland crops, artificial drying offers technical advantages, but it is not economically competitive when energy (oil etc.) prices are high. The economic importance of dried green crops can be increased through development of the organization and technique in the drying industry to ensure better plant material, a more efficient drying temperature and more efficient further processing in the plant. An open, but very important question is: what will the price of energy for the drying plant be in the future?     

Lumpidin, a novel biomarker of some ochratoxin a producing penicillia

The novel compound lumpidin (1) has been isolated as a major compound from an isolate of Penicillium nordicum. Compound 1 is a diketopiperazine with a unique ring system likely to be a condensate of one mole each of L-tryptophan, L-phenylalanine, and L-homo-proline. The fact that 1 has been detected from only three out of sixteen isolates of P. nordicum indicates that lumpidin-producing isolates might represent a separate and third ochratoxin A producing Penicillium species.     

Importing deciduous wood chips from North America to northern Europe – the risk of introducing bark- and wood-boring insects

Increasing inter-continental trade with wood chips represents a challenge for phytosanitary authorities as such trade may lead to pest introductions and invasions with huge impacts on forest ecosystems and economy. Predicting species invasions and their impacts in advance may be difficult, but improved information about potential invasive species ahead of any interceptions is an important precautionary step to reduce the probability of invasions. Here we identify bark- and wood-boring insects that have a potential to become invasive in northern Europe and that may be introduced by import of deciduous wood chips from North America. The potentially most damaging species belong to the beetle genus Agrilus (Buprestidae), which includes the highly damaging emerald ash borer A. planipennis. We give a brief presentation of this and seven other Agrilus species or subspecies and review factors of importance for the risk of establishment and potential economic and ecological impacts of these species. We also discuss one Scolytinae, Hylurgopinus rufipes. There are strong indications in the literature that some north European trees are highly susceptible to attack from the selected beetle species. We therefore conclude that because north European trees have not coevolved with these herbivores and thus may lack adequate defenses, most of the identified beetle species are likely to spread in “defense- and enemy-free space” if they are introduced to northern Europe, with considerable economic and ecological consequences.     

Great scallop, Pecten maximus, research and culture strategies in Norway: a review

The great scallop, Pecten maximus is a potentialaquaculture species in Norway, but production to date has been low. Greatscallop landings in 2000 were 571 tonnes, exclusively from harvesting wildstocks, landed by divers. Approximately two million juveniles of 15mm shell height have been produced annually in a hatchery since1998, and distributed to farmers. Research projects on larvae and juvenilesinclude studies of various antibacterial treatments, improved culture systemdesigns and application of probiotics. Results from hanging cultures underdifferent environmental conditions indicate a strong correlation between lowtemperature and poor survival, and point out the importance of careful selectionof cultivation sites. Good growth potential of scallops in Norwegian waters hasbeen shown, and it is possible to reach market size of 10 mm shellheight in three to four years. Experiments with fences and other strategiesprotecting cultured scallops on the seabed from predation by crabs are inprogress.     

Microbially matured water: a technique for selection of a non-opportunistic bacterial flora in water that may improve performance of marine larvae

Before transfer to larval incubators, water was membrane filtered to remove >95% of the bacteria and then transiently maintained in a biofilter that promoted recolonization of the water by non-opportunistic bacteria. The process is termed microbial maturation of the water. Hypothetically the bacterial flora in the matured water should protect the marine larvae from colonization and proliferation by opportunistic bacteria. Testing of the hypothesis demonstrated 76% higher survival of yolk sac larvae of Atlantic halibut (Hippoglossus hippoglossus) in matured than in membrane filtered water. Proliferation of opportunistic bacteria was observed in the rearing water after hatching of turbot eggs (Scophthalmus maximus), but to a less extent in the microbially matured water. In the early phase of first feeding of turbot larvae, the matured water induced qualitative differences in the gut microflora. Significantly higher initial growth rate of the turbot larvae in the matured water affected 51% higher average weight of 13 days old larvae than in membrane filtered water. Algal addition to the matured water enhanced the larval growth further. The experiments conducted supported the proposed hypothesis that microbial maturation selects for non-opportunistic bacteria, which protects the marine larvae from proliferation of detrimental opportunistic bacteria.     

Potential for improving adaptation ofLolium perenne L. to continental climates in Norway

Summary Breeding of perennial ryegrass has been conducted in Norway for more than 30 years. The little progress achieved so far can, most probably, be explained by a restricted genetic variation within our indigeneous plant material. In order to increase the variation in the Norwegian ryegrass germplasm, we have tested populations of diverse origin and adaptations under contrasting climatic conditions in Norway. Data is presented for winter survival and dry matter yield obtained in two experiments, one in a dense stand with 20 populations of Norwegian and Russian origin, and one as a spaced plant experiment with 26 populations of Norwegian, Russian and Swiss origin. In both cases commercial foreign cultivars and breeding populations were included.The results show that the commercial varieties were superior when grown in dense stand. The Norwegian material showed, however, a significant better adaptation at the continental location, measured as plant cover after three years. There was considerable variation between populations in all characters. In the spaced plant experiment, the Norwegian diploid breeding populations were the highest yielding. The commercial cultivars also performed well. Winter survival was generally good in this experiment, and only small differences between populations could be detected. Winterhardy and productive populations of different origin and contrasting adaptations have been selected, and breeding populations constructed. Surprisingly enough, Swiss Alp populations, presumably adapted to long lasting snow-cover, do not show any better adaptation to the continental climates in Norway than indigeneous ryegrass populations.     

Lactation curves and estimated feed conversion ratios for Simmental,Brown Swiss and Tyrol Grey in Kosovo

Abstract

A total of 2516 test-day milk production records of three dual-purpose cattle breeds, Simmental (S), Brown Swiss (BS), and Tyrol Grey (TG), having their first lactation in Kosovo, were analysed with a repeatability test-day mixed model with the aim of comparing lactation curves and feed conversion ratios of the three breeds. The BS had the highest yield, followed by S and TG. The TG cows tended to have flatter lactation curves than the other breeds. However, as the breeds differed in size, they were also compared throughout lactation for their estimated feed conversion ratios, defined as metabolic body weight per kg of milk (proportional to expected maintenance requirements per kg of milk produced, under certain assumptions). On this criterion BS still ranked highest, while S and TG had similar feed conversion ratios.     

Bacterial Protein Grown on Natural Gas as Feed for Pigs

Bacterial protein meal (BPM) produced by a mixture of Methylococcus capsulatus (Bath), Alcaligenes acidovorans, Bacillus brevis and Bacillus firmus grown on natural gas, was studied as a protein source for pigs. Three growth trials were conducted, one with weanling pigs (Expt 1) and two with growing-finishing pigs (Expts 2 and 3). In Expt 1, 64 appetitefed weanling pigs (10.4 kg average initial weight) were used to determine the effect of adding BPM (0 g, 40 g, 80 g and 120 g kg^-1) to diets replacing traditional protein feedstuffs on growth performance. During week 0-2, adding BPM to diets increased average daily gain (ADG) (linear P < 0.03). During week 0-2 and week 0-4, the 120 g kg^-1 BPM diet increased (P < 0.01) average daily feed intake compared with the control and the 50 g kg^-1