Prevalence and risk factors for Campylobacter spp. in chicken broiler flocks in Reunion Island (Indian Ocean)

Our objectives were to determine Campylobacter prevalence in broiler chicken flocks in Reunion Island and to define specific practices associated with the presence of Campylobacter spp. Infection in Reunionese broiler flocks. Fifty broiler flocks were studied in Reunion Island from May 2007 to February 2009. A questionnaire was submitted to the farmers and samples of fresh droppings were collected to assess the flock's Campylobacter status. Fifty four percent of the flocks were infected by Campylobacter spp.: 30% (95% CI: 28.71-31.29) were infected with Campylobacter coli and 17% (95% CI: 15.95-18.05) with Campylobacter jejuni; only 7% (95% CI: 6.28-7.72) were infected by both species at the same time. Several poultry houses in the farm (OR=11.2; [1.05-92]) and cleaning without any detergent (OR=13.1; [2.1-78.3]) increased the risk of Campylobacter infection. A distance higher than 500 m between broiler farms (OR=0.27; [0.1-0.8]) and use of disinfectant during the rearing period decreased this risk of infection (OR=0.15; [0.1-0.75]).     

Stifle joint osteoarthritis at the time of diagnosis of cranial cruciate ligament injury is higher in Boxers and in dogs weighing more than 35 kilograms

Osteoarthritis is a ubiquitous disease in dogs. The purpose of this retrospective study was to characterize the severity and distribution of osteoarthritis (OA) within the joint and to identify differences among dog breeds in the severity of OA in the cranial cruciate ligament (CCL)‐deficient stifle joint. Radiographs of 240 stifles from 51 Boxers, 66 German Shepherds, 100 Labrador Retrievers, and 23 Siberian Huskies with confirmed CCL rupture were included. Radiographs of the stifle joint were evaluated and OA severity was graded at 33 sites within and around the joint, and patella alta was graded as present or absent for a potential total stifle OA score of 100. Osteophyte size was correlated to OA severity score. Total OA scores were calculated and compared within and between breeds globally as well as at each joint site. Dogs weighing >35 kg had a higher total OA score than those weighing <35 kg. Osteoarthritis scores were highest at the apical patella, proximolateral tibia, and sesamoid bones, corresponding to the proximal, lateral, and caudal aspects of the joint, respectively. No statistically significant differences were found among the mean OA scores of various stifle joint regions. Boxer dogs had a higher total OA score than other breeds. We concluded that dogs have a consistent distribution pattern of OA within the stifle joint after CCL injury. Radiographic OA is more severe in the proximal, lateral, and caudal aspects of the joint. Boxers had more severe OA than the other breeds evaluated in the study.     

Microscopical studies of the effect of metalaxyl on the interaction between sunflower,Helianthus annuus L. and downy mildew,Plasmopara halstedii

The mode of action of the fungicide metalaxyl againstPlasmopara halstedii, the causal agent of sunflower downy mildew, was studied following its application before, during and after artificial contamination of seedlings. The development of the fungus within the treated seedlings was examined microscopically and compared to that occuring in untreated genetically susceptible or resistant genotypes. Hypersensitive-like reactions and necrotic zones leading to the inhibition of fungus growth within the hypocotyl were observed for the three modes of application. This suggests that sunflower defence mechanisms activated by genetical resistance are also involved in the control of downy mildew by metalaxyl.     

Biological activity of neem seed kernel extracts and synthetic azadirachtin against larvae of Plutella xylostella L

The activity of two neem extracts, AZT and NEEM-AZAL (containing 30 and 3 mg azadirachtin ml^?1 respectively) and synthetic azadirachtin (AZ) against second-instar larvae (L2) of Plutella xylostella L. was examined using leafdip bioassays. On Chinese cabbage, AZ was significantly (P <0.05) less toxic (3 to 4-fold; LC₅₀ 0.54 μg AZ ml^?1) than either neem extract against a laboratory strain of P. xylostella (FS). The LC₅₀ values for AZT against the FS and another laboratory strain (Wellcome) were not significantly different on Chinese cabbage. The activity of AZT against the FS and Wellcome strains was similar on Chinese cabbage and Brussels sprout. AZT was significantly less toxic (3-fold) on Brussels sprout against an acylurea-resistant field strain (Sawi) when compared with the FS strain on Chinese cabbage. Larval mortality (at day 13) was found to increase with increasing exposure time of P. xylostella (FS) larvae to AZT-treated Chinese cabbage, although there was little difference in mortality between 48 and 120 h exposure. When AZT, NEEM-AZAL and AZ were applied at a dose (1 μg AZ ml^?1) which gave end-point mortalities between 50 and 90% (at day 13), all treatments delayed the development of a proportion of surviving larvae but no morphogenetic abnormalities were observed in larvae which reached pupation. Evidence for antifeedant (reduced weight gain) and repellant effects (choicechamber) for AZT were observed with L2 P. xylostella (Wellcome) on Chinese cabbage. AZT was also shown to have ovicidal activity against P. xylostella (Wellcome) at relatively high dose ranges (10-1000 μg AZ ml^?1) as well as some contact activity (FS strain) in topical bioassays. In residual bioassays on glass with adults of the hymenopteran endo-larval parasitoid of P. xylostella, Diadegma semiclausum (Ichneumonidae), AZT showed little or no activity at rates up to 1000 μg AZ ml^?1. In medium-volume (MV, 200 litre ha^?1) and ultra-low-volume (c. 1 litre ha^?1) spray bioassays on Brussels sprout, AZT gave 16-92% and 88-100% mortality respectively (Wellcome strain) at rates approximating to 1-20 g AZ ha^?1. The residual activity of AZT and NEEM-AZAL against P. xylostella (FS) on Brussels sprout (MV spray) was observed to decrease appreciably after three days, the decline in activity being particularly marked for NEEM-AZAL.     

Differential effects of the acylurea insect growth regulator teflubenzuron on the adults of two endolarval parasitoids of Plutella xylostella,Cotesia plutellae and Diadegma semiclausum

The acylurea chitin synthesis inhibitor, teflubenzuron (‘Nomolt’® SC) showed no apparent activity against adult males of Diadegma semiclausum Hellén or Cotesia plutellae Kurdj. when applied to foliage at a rate ( = 50 g a.i. ha^?1) approximating to 2 × field usage. In contrast, the pyrethroid cypermethrin (‘Cymbush’® EC) showed appreciable foliar activity (at rates = 10–50 ga.i. ha^?1) to D. semiclausum but showed low activity against C. plutellae. When single adult female D. semiclausum were pre-treated with teflubenzuron (= 50 g a.i. ha^?1) and then exposed to 5. 10. 25, 50 or 100 second-instar host larvae, the number of purasitoid cocoons formed was significantly reduced compared with controls except at the lowest host density (P 0-05). However, there was no evidence that teflubenzuron had a host density-dependent effect on parasitism by D. semiclausum. Teflubenzuron had no significant effect on host parasitism in an equivalent experiment with C. plutellae (P > 0-05) except at the median host density. When batches of ten host larvae were introduced at hourly intervals to female D. semiclausum pre-treated with teflubenzuron (= 50 g a.i. ha^?1), the number of cocoons formed in the first two batches was not significantly different from untreated controls (P > 0-05), whereas teflubenzuron significantly reduced the number of cocoons in the next three batches of host larvae (P < 0-05). This suggests that teflubenzuron may affect chitin synthesis in developing eggs within female D. semiclausum but has little or no effect on pre-formed eggs which are more likely to be oviposited first. Teflubenzuron had no significant (P > 0-05) effect on parasitism by C. plutellae when presented with batches of host larvae. When female D. semiclausum and C. plutellae were placed in the same host arena, the former showed a 3-fold greater rate of parasitism. Pre-treatment with teflubenzuron significantly reduced parasitism by D. semiclausum (P > 0-05) but had no significant effect with C. plutellae (P > 0-05) although the latter species failed to exploit the reduction in parasitism by D. semiclausum. The differential response of D. semiclausum and C. plutellae to insecticides is discussed in relation to the relative rates of establishment of these species in Malaysia.     

Assessment of impulse duration thresholds for electrical stimulation of muscles (chronaxy) in dogs

OBJECTIVE: To determine the electrical impulse duration thresholds (chronaxy) for maximal motor contraction of various muscles without stimulation of pain fibers in dogs. ANIMALS: 10 healthy adult Beagles. PROCEDURES: The dogs were used to assess the minimal intensity (rheobase) required to elicit motor contraction of 11 muscles (5 in the forelimb [supraspinatus, infraspinatus, deltoideus, lateral head of the triceps brachii, and extensor carpi radialis], 5 in the hind limb [gluteus medius, biceps femoris, semitendinosus, vastus lateralis, and tibialis cranialis], and the erector spinae). The rheobase was used to determine the chronaxy for each of the 11 muscles in the 10 dogs; chronaxy values were compared with those reported for the corresponding muscles in humans. RESULTS: Compared with values in humans, chronaxy values for stimulation of AA motor fibers in the biceps femoris and semitendinosus muscles and muscles of the more distal portions of limbs were lower in dogs. For the other muscles evaluated, chronaxy values did not differ between dogs and humans. CONCLUSIONS AND CLINICAL RELEVANCE: Application of the dog-specific chronaxy values when performing electrical stimulation for strengthening muscles or providing pain relief is likely to minimize the pain perceived during treatment in dogs.     

Comparison of 2-step laparoscopy-guided abomasopexy versus omentopexy via right flank laparotomy for the treatment of dairy cows with left displacement of the abomasum in on-farm settings

OBJECTIVE: To compare characteristics and results of 2-step laparoscopy-guided abomasopexy versus omentopexy via laparotomy in the right paralumbar fossa for the treatment of dairy cows with a left displaced abomasum (LDA). DESIGN: Prospective clinical trial. 253 dairy cows with an LDA. PROCEDURES: All cows that were treated with omentopexy (n = 101) or 2-step laparoscopy-guided abomasopexy (152) from July 2005 through December 2006 were included. Presurgical, perisurgical, and postsurgical information was recorded by attending veterinarians. Producers were interviewed by telephone 7 and 60 days after surgery regarding the response of cows to surgery. Characteristics of and responses to the 2 surgical techniques were compared. RESULTS: At 7 days after surgery, the 2 groups of cows were not significantly different with respect to appetite, comfort, and milk yield; at 60 days after surgery, groups were similar with respect to milk yield, cull rates, and risk of relapse of LDA. Antimicrobial treatment in response to postsurgical pyrexia was necessary in only 20.4% (31/152) of cows that were treated with 2-step laparoscopy-guided abomasopexy. Mean duration (preparation and surgery) of 2-step laparoscopy-guided abomasopexy was significantly less than that of omentopexy (36 vs 74 minutes, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Results of 2-step laparoscopy-guided abomasopexy and omentopexy via laparotomy in the right paralumbar fossa were not significantly different. Compared with omentopexy, laparoscopy-guided abomasopexy was performed more quickly and required postsurgical administration of antimicrobials less frequently. Although these factors may be of economic consequence to veterinarians and producers, other aspects must also be considered when choosing between techniques.     

Interleukin-1β infusion in bovine mammary glands prior to challenge with <Emphasis Type="Italic">Streptococcus uberis</Emphasis> reduces bacterial growth but causes sterile mastitis

Dairy cows are especially vulnerable to intramammary infection by the bacterial pathogen Streptococcus uberis in the dry period. Use of immunotherapeutic agents at drying off could increase cellular defences in the gland and prevent establishment of new S. uberis infections. This study investigated the potential of infusing recombinant bovine interleukin-1 beta (rbIL-1beta) in the mammary glands as a prophylactic agent against subsequent intramammary challenge with S. uberis in the early dry period. Immediately after the last milking at commencement of the dry period, one cow from each of 10 monozygous twinsets was infused with 10 microg of rbIL-1beta in two quarters and the other twin was infused with the carrier agent, sterile phosphate buffered saline. Twenty-four hours later, the quarters were infused with 10(3) colony-forming units (CFU) of S. uberis. Bacteriology, somatic cell count (SCC), concentrations of specific cytokines and antibody responses were monitored in mammary gland secretions and sera for the next 21 days. Infusion of rbIL-1beta into mammary glands at commencement of the dry period was associated with less new S. uberis intramammary infections, as determined by the number of quarters with bacterial growth. However, high SCC in quarters following infusion of rbIL-1beta masked the full beneficial effect of this procedure.     

AMINO ACID APPLICATION CAN BE AN ALTERNATIVE TO PREVENT GLYPHOSATE INJURY IN GLYPHOSATE-RESISTANT SOYBEANS

Glyphosate-resistant (GR) soybeans have continuously increased; however, this expansion significantly increased the use of glyphosate and therefore, in some cases, has resulted in injury symptoms observed in GR soybean, known as “yellow flashing”. Previous reports of interference of glyphosate with nutrient availability and utilization by GR soybean may be linked to this injury symptom. Also, because glyphosate interferes with amino acid synthesis, supplementation with exogenous amino acids may help GR soybean recover from adverse effects of glyphosate. Therefore, an experiment was designed to evaluate different amino acid concentrations. Near-isogenic and GR soybean varieties were grown in the greenhouse in two soils with and without glyphosate at different rates and amino acids were foliarly applied with and without glyphosate. In general, the photosynthetic variables, nutrient contents, and shoot and root dry biomass parameters were affected by glyphosate, however, use of amino acid formulations suppressed harmful effects of glyphosate on these parameters.