Effects of leucocyte extract, levamisole and sulphadimidine on natural coccidial infections (Eimeria spp.) in young lambs

The efficacy of leucocyte extract (LE) and sulphadimidine in preventing coccidiosis in naturally infected lambs on pasture was evaluated in 3 separate experiments, whereas the prophylactic effect of levamisole was studied in 1 of the experiments. LE prepared from ewes immune to coccidia (Eimeria spp.) was administered either intravenously or intraperitoneally to young lambs 7, 5, or 2 days before they were turned out on pastures contaminated with coccidia. In all experiments, LE failed to transfer protective immunity to the lambs against the first coccidial infection on pasture. The LE preparations used apparently had an immunosuppressive effect, which resulted in more severe clinical signs of coccidiosis in the recipients. The lambs given LE showed a higher incidence of diarrhoea, a poorer weight gain, a higher mortality, and a higher oocyst output than the untreated control lambs. In lambs treated with sulphadimidine at 200 mg/kg on days 12, 13, and 14 after turnout there was a reduced severity of the coccidial infections in all experiments. The sulphadimidine-treated lambs had better weight gains and passed fewer oocysts than the controls during the third and fourth week after turnout, but some of them developed diarrhoea. Lambs treated with levamisole at 2 mg/kg 2 days before turnout, at turnout, and 2 days after turnout were more severely affected by the first coccidial infection on pasture than the controls.To study the lambs’ immunity against a heavy challenge infection with coccidia as compared with their immunity against the natural reinfection on pasture, some of the lambs from the original groups (untreated, sulphadimidine-treated, LE-treated) were each inoculated with 2 mill. Eimeria spp. oocysts about 6 weeks after turnout. The oocyst counts of the challenged lambs, except the LE-treated lambs, increased to a new peak 19–20 days after challenge. The challenge infection caused a softening of the faeces and a marked depression in weight gain in all challenged groups of lambs, mainly between days 10 and 17 after challenge. The lambs were thus only partially immune to coccidia after the first coccidial infection on pasture. The lambs treated with either LE or sulphadimidine in connection with the first coccidial infection on pasture were not appreciably more susceptible to the challenge infection than the untreated lambs.     

Mortality of purebred and mixed-breed dogs in Denmark

Causes of death and age at death of 2928 dogs are reported from a questionnaire study among members of the Danish Kennel Club (DKC) in 1997. The dogs represented 20 breeds, 15 breed-groups and a group of mixed-breed dogs. The median age at death for all dogs in the study was 10.0 years. Mixed-breed dogs had a higher median age at death (11.0 years) than the entire population, but breeds like Shetland Sheepdog, Poodle and Dachshund exceeded this age (12 years). The Bernese Mountaindog, the group of Molossian types and the Sighthounds had the shortest life span with a median age at death of 7.0 years. Old age was the most frequent reported cause of death (20.8%) followed by cancer (14.5%), behavioural problems (6.4%) accidents (6.1%), hip dysplasia (4.6%), heart diseases (4.6%) and spinal diseases (3.9%). Breed-specific proportional mortalities with 95% confidence limits are given for the six most prevalent specific causes of death.     

The new classification system for slaughter-pig herds in the Danish Salmonella surveillance-and-control program

The Danish surveillance-and-control program for Salmonella in slaughter pigs was introduced in 1995. The key element of the program is a quick and correct identification of herds with high seroprevalence. After 5 years, the classification scheme was evaluated--and a revision was made. Data from two Salmonella screenings including a total of 1902 slaughter pig herds were used. For each herd, information was available on Salmonella status based on both microbiology and serology. Based on analyses of these data, suitable changes in the scheme were identified and their effect estimated by use of data from the Danish Salmonella Database including all herds in 2000. The classification scheme has been adjusted on the following points. (1) The sampling has been simplified into 60, 75, or 100 samples per herd per year depending on herd size. This means more-precise estimates for the seroprevalence among smaller herds. (2) Herds with an annual kill or=index 40, and the limit between Levels 2 and 3 to >or=index 70. If the Danish swine producers are interested, a Level 0 may be introduced (consisting of seronegative herds as an indication of a negligible Salmonella prevalence). The classification scheme was introduced in August 2001.     

Het voorkomen van resistentie tegen organische fosforverbindingen bij de bonespintmijt (Tetranychus urticae) in Aalsmeer

Samenvatting Bij een onderzoek naar de gevoeligheid voor acariciden van spintpopulaties, afkomstig van verschillende bedrijven in Aalsmeer, bleek in 20 van de 22 onderzochte gevallen een resistentie te bestaan tegen organische fosforverbindingen. Deze resistentie bleek ook te bestaan ten opzichte van organische fosforverbindingen, die nooit eerder tegen de onderzochte spintpopulaties gebruikt waren. De resistentie tegen demeton (Systox) bleek bij enkele populaties niet even groot.Tegen acariciden op basis van gechloreerde koolwaterstoffen zoals kelthane en chloorbenzilaat, werd nog geen resistentie bij de onderzochte populaties aangetroffen.Een onderzoek naar de gevoeligheid voor acariciden van spintpopulaties, welke in de directe omgeving buiten de kassen op onkruiden e.d. voorkomen, leidde tot de conclusie dat resistente spintmijten niet buiten de kas voorkomen. De resistentie van spintpopulaties is op de verschillende bedrijven in Aalsmeer zelfstandig spontaan opgetreden. Er bleek geen correlatie te bestaan tussen de verschillende waardplanten (roos, anjer enGerbera) en het optreden van resistentie.Summary During the year 1958 the susceptibility to acaricides of a number of populations of the two-spotted spider mite (Teranychus urticae Auct.) occurring in several nurseries in Aalsmeer (fig. 5) was studied at the Experimental Station for Floriculture at Aalsmeer, The Netherlands.The susceptibility of a population was examined by placing 50 adult female mites on a bean plant, treated with an acaricide. The percentage mortality was determined after four days.In these experiments both spider mite populations in the greenhouses (on roses, carnations andGerbera) and those in the open air near the greenhouses (on weeds) were studied. Fig. 1 gives the susceptibility of the different populations for water, parathion, diazinon, demeton (Systox) and kelthane. Of the 22 populations from glasshouses 20 proved to be resistant to organic P-compounds. Of those collected from weeds growing outside the greenhouses, not a single one proved to be resistant, so that it may be taken for granted that the resistant red spider mite, found in the greenhouse, does not survive outside.A number of populations were examined for their susceptibility to some other acaricides (fig. 2). In this experiment the resistance to those organic P-compounds with which the populations had never been treated before, such as phosdrin, thiometon and phenkapton was observed. It clearly illustrates that there is no question of resistance to a definite acaricide, but to the group of organic P-compounds. Resistance to demeton did not prove to be equally strong for every population.In all cases examined chlorinated hydro-carbons, such as kelthane and chlorobenzilate, proved to be normally active. Resistance to this group of acaricides has not yet been found in Aalsmeer.A special case is stated in fig. 3, where the spider mite population in a cucumberhouse, in which no chemical control had been applied, is compared with a population on nettles outside the glasshouse and a resistant population in a rosehouse of the same nursery.An experiment, repeated on several dates over a period of 13 months (fig. 4), shows that there was no important shift in the susceptibility of the population studied. It is clear that the resistance of two-spotted spider mites to organic P-compounds has been developed in Aalsmeer independently in more than twenty separate glasshouses.In no case the host plant (carnation, rose,Gerbera) proved to have an appreciable influence on the appearence of resistance.     

The content of biogenic amines in canned fish from the Turkish market

This paper describes the determination of biogenic amines in a number of canned fish of the Turkish market by means of HPLC. Over all 39 cans of sardine, tuna, sardel, mackerel, pelamide and trout were tested. The determination of agmatine, cadaverine, histamine, putrescine and tyramine was performed by HPLC with post column derivatization with ortho-phthaldialdehyde. Four samples contained higher amounts of biogenic amines (three sardine samples contained more than 1000 mg/kg histamine) while all other samples were acceptable. These results demonstrate the need of instrumental analyses in the quality control system of Turkish producers of canned fish. The quality of the products at least of some producers has to be improved, e.g. by cooperation between the official food control and the quality assurance system of the producers.     

Effects of temperature and adrenaline on the atrial myocardium of the cultured Atlantic salmon (Salmo salar)

The effects of acute temperature changes (2–17°C) on myocardial contractility with or without adrenergic activation were studied in the isolated spontaneously beating atrium of the Atlantic salmon (Salmo salar) reared at 8°C. The atrial frequency was markedly elevated (from 7 to 46 beats/min) by the rise in temperature from 2–17°C. Both the time to peak tension and to relaxation time were shortened. In contrast, the temperature effect on the maximal tension was modest. Exposure to exogenous adrenaline (1.1 nM–11 μM) resulted in a substantial enhancement of the maximal tension, notably at 2°C, while potentiation of the frequency at 2, 8 and 14°C, was less pronounced. The apparent affinity (pD₂) for adrenaline on the chronotropy was higher at 8 and 14°C than at 2°C. For the inotropic responses pD₂ was highest at the acclimation temperature (8°C). By comparison with data for the rainbow trout (Oncorhynchus mykiss) obtained by the same experimental design (Ask et al. 1981), species differences were apparent both in temperature dependence of contractile parameters and in their adrenergic activation. The Q₁₀ for the frequency in absence of adrenaline was higher in the salmon than in the trout for the temperature interval 2–17°C. The apparent affinities for adrenaline for the frequency at 8°C and 14°C and for the maximal tension responses at 2°C and 8°C were also highest for the salmon atrium.