Effects of cimaterol on rabbit growth and myofibrillar protein degradation and on calcium-dependent proteinase and calpastatin activities in skeletal muscle

The objectives of this study were to examine effects of a beta-adrenergic agonist (cimaterol) on growth and muscle development in rabbits and to examine cimaterol's effects on myofibrillar protein degradation (MPD) and on activities of several proteolytic enzymes including the calcium-dependent proteinases (CDP). Twelve New Zealand White rabbits were assigned to either control diets or to diets containing cimaterol for 35 d, after which they were killed and effects on performance and tissue weight gains were determined. Urine was collected from d 21 through 28 from each rabbit for assessment of N tau-methylhistidine (NMH) excretion. Cimaterol increased rates of gain, efficiency of gain and skeletal muscle weights. Enhancement in muscle weight was associated with an increase in total DNA and with a reduction in NMH. Cimaterol did not affect activities of cathepsin B, cathepsin D or neutral serine proteinase, but it reduced activities of the millimolar and micromolar forms of the CDP by 58 and 57%, respectively, and it reduced activity of the inhibitor of the CDP (calpastatin) by 52%. Cimaterol-dependent myofibrillar protein accretion was likely mediated, at least in part, by a reduction in MPD. The change in MPD was associated with a reduction in muscle CDP activities. Cimaterol-dependent muscle hypertrophy therefore may involve changes in calcium-dependent proteolysis of myofibrillar proteins. The significance of the effects of cimaterol on calpastatin activity is not known.     

Demonstrating freedom from disease using multiple complex data sources 2: case study--classical swine fever in Denmark

A method for quantitative evaluation of surveillance for disease freedom has been presented in the accompanying paper (Martin et al., 2007). This paper presents an application of the methods, using as an example surveillance for classical swine fever (CSF) in Denmark in 2005. A scenario tree model is presented for the abattoir-based serology component of the Danish CSF surveillance system, in which blood samples are collected in an ad hoc abattoir sampling process, from adult pigs originating in breeding herds in Denmark. The model incorporates effects of targeting (differential risk of seropositivity) associated with age and location (county), and disease clustering within herds. A surveillance time period of one month was used in the analysis. Records for the year 2005 were analysed, representing 25,332 samples from 3528 herds; all were negative for CSF-specific antibodies. Design prevalences of 0.1-1% of herds and 5% of animals within an infected herd were used. The estimated mean surveillance system component (SSC) sensitivities (probability that the SSC would give a positive outcome given the animals processed and that the country is infected at the design prevalences) per month were 0.18, 0.63 and 0.86, for among-herd design prevalences of 0.001, 0.005 and 0.01. The probabilities that the population was free from CSF at each of these design prevalences, after a year of accumulated negative surveillance data, were 0.91, 1.00 and 1.00. Targeting adults and herds from South Jutland was estimated to give approximately 1.9, 1.6 and 1.4 times the surveillance sensitivity of a proportionally representative sampling program for these three among-herd design prevalences.     

Effets de divers herbicides sur la croissance mycélienne de souches de Botrytis cinerea pers et de Penicillium expansum Link, sensibles ou résistantes à certains fongicides

Effects of various herbicides on mycelial growth of strains of Botrytis cinerea. Pers. and Pénicillium expansum Link, sensitive or resistant to certain fungicides Of seventy herbicides tested, thirty-eight were slightly toxic to B. cinerea (CI50, concentration giving 50% inhibition of the speed of mycelial growth, exceeding or equal to 100g of herbicide/ml of nutrient solution) and, of those, ten had no effect even at 1000 g/ml. The most active products (CI50 less than 10 g/ml) were Chlorthiamid, dichlobénil, nitrofen, propyzamide and phenolic derivatives (DNOC, ioxynil, PCP). In most cases P. expansum was less sensitive than B. cinerea except to endothal, propachlor, prynachlor and certain substituted ureas. Strains resistant to the benzimidazole fungicides (carbendazim, thiabendazole etc.) show increased sensitivity to certain carbamade herbicides (barban, chlorbufam etc.), this indicates the existence of a negative cross resistance between these groups of antimitotic pesticides. Strains resistant to the cyclic-imide fungicides (iprodionc, procymidone, vinclozolin) and to various aromatic compounds (biphenyl. chloroneb, dicloran etc.) may also be resistant to bipyridilium, dinitroanilinc and diphenylethcr herbicides, to chlorthamid. dichlobénil and oxadiazon. This cross resistance between pesticides with different biochemical modes of action has yet to be explained.     

Susceptibility of chicks to infectious bursal disease (IBD) following vaccination of their parents with live IBD vaccine.

Vaccination of parent chickens with a commercial live infectious bursal disease (IBD) vaccine under field conditions at varying ages and by different routes resulted in variable susceptibility to the disease in their chicks. There was little correlation between the methods of vaccination and the levels of immunity in the chicks. There was some evidence that levels of transferred immunity decreased with the age of the parents. Of five flocks examined, the onset of susceptibility to IBD occurred at two days of age in two flocks and about one week of age in the other three. Four flocks were completely susceptible by the 27th day, the other at 31 days. Precipitins were demonstrated at day old in 100 per cent of chicks in three flocks and in 80 per cent in the other two. The precipitins had disappeared in all flocks by 17 days of age.     

Humoral Response to 2 Inactivated Bluetongue Virus Serotype‐8 Vaccines in South American Camelids

Background: Bluetongue virus serotype 8 (BTV‐8) has caused disease in domestic ruminants in several countries of northern Europe since 2006. In 2008 a mass‐vaccination program was launched in most affected countries using whole virus inactivated vaccines. Objective: To evaluate 2 inactivated vaccines (Bovilis BTV 8; BTVPUR AlSap8) for immunogenicity and safety against BTV‐8 in South American camelids (SAC) in a field trial. Animals: Forty‐two SAC (25 Alpacas, 17 Llamas) aged between 1 and 16 years. Methods: The animals were vaccinated twice at intervals of 21 days. They were observed clinically for adverse local, systemic, or both reactions throughout the trial. Blood samples collected on days 0, 14, 21, 43, and 156 after vaccination were tested for the presence of BTV‐8 virus by real time‐polymerase chain reaction and of specific antibodies by competitive ELISA and a serum neutralization test. Results: All vaccinated animals developed antibodies to BTV‐8 after the 2nd administration of the vaccine. No adverse effects were observed except for moderate local swellings at the injection site, which disappeared within 21 days. Slightly increased body temperatures were only observed in the first 2 days after vaccination. The BTV was not detected in any of the samples analyzed. Conclusions and Clinical Importance: The administration of the 2 inactivated commercial vaccines was safe and induced seroconversion against BTV‐8 in all vaccinated animals. The results of this study suggest that 2 doses injected 3 weeks apart is a suitable vaccination regimen for SAC.     

Failure to observe cross-fertilization between the Echinococcus granulosus G1 and G6 strains after an experimental mixed infection of the definitive host

The classification within Echinococcus granulosus is currently under debate. To assess the reproductive potential between the G1 and G6 strains, an experimental double infection was carried out in a dog. First, two fertile hydatid cysts were collected in Algeria from a cow and a dromedary. They were identified as being G1 and G6 with the markers coxI and nadI. Subsequently, a dog was inoculated with protoscoleces from these two cysts. Sixty days after infection, 85 adult worms were recovered from the intestine of the dog. Then, the two cysts and each of these individual parasites were characterized with the multilocus microsatellite EmsB and compared. For all worms, the scolex and the gravid proglottids, separately analyzed, provided an identical profile: the G1 profile was observed in 70 adults, and the G6 profile in the 15 others. No single worm exhibited a hybrid G1/G6 profile. This result suggests the absence of cross-fertilizing between the two taxa under the given experimental conditions, and so, the presence of a strong cross-reproductive barrier. This observation corroborates with the recent reclassification of G1 and G6 within two distinct species.     

Feline leukaemia. ABCD guidelines on prevention and management

OverviewFeline leukaemia virus (FeLV) is a retrovirus that may induce depression of the immune system, anaemia and/or lymphoma. Over the past 25 years, the prevalence of FeLV infection has decreased considerably, thanks both to reliable tests for the identification of viraemic carriers and to effective vaccines.InfectionTransmission between cats occurs mainly through friendly contacts, but also through biting. In large groups of non-vaccinated cats, around 30–40% will develop persistent viraemia, 30–40% show transient viraemia and 20–30% seroconvert. Young kittens are especially susceptible to FeLV infection.Disease signsThe most common signs of persistent FeLV viraemia are immune suppression, anaemia and lymphoma. Less common signs are immune-mediated disease, chronic enteritis, reproductive disorders and peripheral neuropathies. Most persistently viraemic cats die within 2–3 years.DiagnosisIn low-prevalence areas there may be a risk of false-positive results; a doubtful positive test result in a healthy cat should therefore be confirmed, preferably by PCR for provirus. Asymptomatic FeLV-positive cats should be retested.Disease managementSupportive therapy and good nursing care are required. Secondary infections should be treated promptly. Cats infected with FeLV should remain indoors. Vaccination against common pathogens should be maintained. Inactivated vaccines are recommended. The virus does not survive for long outside the host.Vaccination recommendationsAll cats with an uncertain FeLV status should be tested prior to vaccination. All healthy cats at potential risk of exposure should be vaccinated against FeLV. Kittens should be vaccinated at 8–9 weeks of age, with a second vaccination at 12 weeks, followed by a booster 1 year later. The ABCD suggests that, in cats older than 3–4 years of age, a booster every 2–3 years suffices, in view of the significantly lower susceptibility of older cats.