Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds

The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems.     

Carbon flux and growth in mature deciduous forest trees exposed to elevated CO2

Whether rising atmospheric carbon dioxide (CO2) concentrations will cause forests to grow faster and store more carbon is an open question. Using free air CO2 release in combination with a canopy crane, we found an immediate and sustained enhancement of carbon flux through 35-meter-tall temperate forest trees when exposed to elevated CO2. However, there was no overall stimulation in stem growth and leaf litter production after 4 years. Photosynthetic capacity was not reduced, leaf chemistry changes were minor, and tree species differed in their responses. Although growing vigorously, these trees did not accrete more biomass carbon in stems in response to elevated CO2, thus challenging projections of growth responses derived from tests with smaller trees.     

Food supplementation: A tool to increase reproductive output? A case study in the threatened Florida Scrub-Jay

The federally threatened Florida Scrub-Jay (Aphelocoma coerulescens) has suffered dramatic losses in recent years primarily because of overdevelopment of its unique scrub habitat. Ensuring the survival of this species will require not only measures to reduce habitat loss, but also efforts to increase the numbers of birds in small scattered populations to a point at which they are resilient to extinction from stochastic population fluctuations. Here we evaluate the utility of providing supplementary food during the pre-breeding season as a means of increasing the reproductive output of Florida Scrub-Jays. Data collected from 2000 to 2007 at Archbold Biological Station in south-central Florida indicate a marked effect of supplemental feeding on reproductive output. This increased output appeared to result primarily from larger clutch sizes produced by supplemented female breeders as a result of their advanced laying. Supplementation also increased offspring survival probabilities and the early laying permitted more renesting attempts. Furthermore, annual variation in several reproductive measures was dampened in supplemented birds, suggesting that supplemental feeding may reduce environmental or stochastic effects on reproductive output. Although a number of potential problems may be associated with supplemental feeding (e.g., predator entrainment and increased opportunity for disease transmission), it can serve as a valuable tool for management agencies that wish to rapidly increase local carrying capacity. In addition, food supplementation might benefit translocation efforts both by increasing the number of potential translocation candidates from a donor population and then by supplementing the newly established population to promote rapid growth.     

Analysis of bacterial load and prevalence of mixed infections with Lawsonia intracellularis, Brachyspira hyodysenteriae and/or Brachyspira pilosicoli in German pigs with diarrhoea

Lawsonia (L.) intracellularis, Brachyspira (B.) hyodysenteriae and B. pilosicoli are important pathogens in domestic pig production world-wide, responsible for porcine intestinal adenomatosis, swine dysentery, and porcine intestinal spirochetosis, respectively. Conventional PCR is the major diagnostic tool in the detection of the three pathogens, but the sole detection of bacterial DNA might lead to misinterpretations of results with respect to their clinical relevance, especially with mixed infections. Thus, the present study targeted the detection and quantification of the three pathogens in samples from herds with a case history of diarrhoea. Herds and samples were selected by the practitioners on a voluntary basis. Results were based on 1176 individual samples from 95 herds from Southern Germany. The pathogens were detected simultaneously by multiplex real-time PCR. The overall prevalence for L. intracellularis, B. hyodysenteriae and B. pilosicoli was 12.6%, 8.4% and 3.2% in faecal samples and 48.4%, 24.2% and 31.6% in herds, respectively. Sixty one percent, 82.6%, and 73.4% of herds positive for L. intracellularis, B. hyodysenteriae, and B. pilosicoli, respectively, had mixed infections. Median log values of DNA equivalents/g of faeces for L. intracellularis, B. hyodysenteriae and B. pilosicoli were 3.3, 5.9 and 3.2, with maxima of 8.3, 8.0 and 6.3, respectively. Within herd prevalence of B. hyodysenteriae and B. pilosicoli as well as the load of B. hyodysenteriae were significantly associated with the severity of diarrhoea.     

提高生产性能,降低用药成本

现代畜牧生产以其较高的遗传潜力而闻名,但由于动物的生命周期之中存在不同且复杂的挑战而往往导致无法获得较高的遗传潜力。本文介绍比利时Innovad公司生产的Lumance产品和Lumance Zn产品经证明是有效提高动物生产性能的产品。     

Airway management under general anaesthesia in pigs using the LMA-ProSeal: a pilot study

OBJECTIVE: Evaluation of the LMA-ProSeal for positive pressure ventilation (PPV) in the pig. STUDY DESIGN: Prospective observational study. ANIMALS: Twelve German country pigs, weighing 25-62 kg. METHOD: Lungs of pigs were mechanically ventilated under general anaesthesia using the LMA-ProSeal. The ease of insertion, number of attempts and total time until placement of the LMA-ProSeal and gastric tube were recorded. Bronchoscopy was performed to determine the position of the LMA-ProSeal and to detect signs of aspiration. Ventilation variables and the leak airway pressure (P(leak)) were measured. An arterial blood gas sample was taken to determine the adequacy of ventilation. RESULTS: The airway was secured in all pigs within 39 +/- 19 seconds (27-51). Different sizes of LMA-ProSeal were used; up to 30 kg: size 3, up to 43 kg: size 4; and above 43 kg: size 5. In all but one animal the P-LMA and gastric tube were inserted at the first attempt. In nine animals gastric fluid was drained through the gastric tube. There was no evidence of aspiration in any animal. The mean [+/-SD (95%CI)]P(leak) was 28.8 +/- 7.5 cm H(2)O (24.06-33.60) and normal ventilation was achieved in all animals. CONCLUSIONS: The results of this study indicate that the airway of pigs weighing 25-62 kg can be secured safely and reliably with the sizes 3, 4 and 5 LMA-ProSeal. CLINICAL RELEVANCE: Endotracheal intubation in pigs can be difficult so there is a risk of hypoxemia in the apnoeic animal. With the LMA-ProSeal the airway can be secured rapidly, safely and reliably. Use of the Standard-LMA under PPV can be associated with gas leakage into the stomach and the subsequent risk of gastric distension and regurgitation. Both the ability to drain the stomach and the high P(leak) of the LMA-ProSeal could contribute to improved protection against aspiration under PPV.     

Shedding of food-borne pathogens and microbiological carcass contamination in rabbits at slaughter

To obtain microbiological data from rabbits at slaughter, 500 fecal samples and 500 carcasses samples were examined. All samples tested negative for Listeria and Salmonella. Campylobacter were detected in two fecal samples. Of the 500 fecal samples, 45.8% tested positive for eae (intimin), 1.2% for stx (Shiga toxin), and 1.8% for both eae and stx. By colony hybridization, 56 eae positive Escherichia coli strains were isolated. Among them, 27 strains (48.2%) were of the serotypes O178:H7 and O153:H7, whereas 15 strains (26.8%) belonged to a serogroup that has not yet been described (O(CB10681):H7). All strains possessed intimin beta1 and the translocated intimin receptor (tir) capable of being tyrosine phosphorylated. None of the strains harbored the genes for Shiga toxins, EAST1 (astA), bundlin (bfpA), or the EAF plasmid. Slaughter rabbits therefore constitute a reservoir for certain atypical enteropathogenic Escherichia coli. On rabbit carcasses, average total bacterial counts accounted for 3.3 log CFU cm(-2). Enterobacteriaceae and coagulase positive staphylococci (CPS) were detected on 118 (23.6%) and 153 (30.6%) carcasses, respectively. Enterobacteriaceae and CPS counts of positive samples were mainly <1.5 log CFU cm(-2). Among 153 selected CPS isolates, 98.7% were identified as Staphylococcus aureus. None of the 151 isolated strains harbored the gene for methicillin resistance (mecA). Genes for staphylococcal enterotoxins (SE) were detected in 102 strains. The combinations of seg and sei (53 strains) and sed, seg, sei, and sej (27 strains) dominated.     

Comparison of fecal culture and F57 real-time polymerase chain reaction for the detection of Mycobacterium avium subspecies paratuberculosis in Swiss cattle herds with a history of paratuberculosis

Background

Bovine paratuberculosis is an incurable chronic granulomatous enteritis caused by Mycobacterium avium subspecies paratuberculosis (MAP). The prevalence of MAP in the Swiss cattle population is hard to estimate, since only a few cases of clinical paratuberculosis are reported to the Swiss Federal Food Safety and Veterinary Office each year.Fecal samples from 1,339 cattle (855 animals from 12 dairy herds, 484 animals from 11 suckling cow herds, all herds with a history of sporadic paratuberculosis) were investigated by culture and real-time polymerase chain reaction (PCR) for shedding of MAP.

Results

By culture, MAP was detected in 62 of 445 fecal pools (13.9%), whereas PCR detected MAP in 9 of 445 pools (2.0%). All 186 samples of the 62 culture-positive pools were reanalyzed individually. By culture, MAP was grown from 59 individual samples (31.7%), whereas PCR detected MAP in 12 individual samples (6.5%), all of which came from animals showing symptoms of paratuberculosis during the study. Overall, MAP was detected in 10 out of 12 dairy herds (83.3%) and in 8 out of 11 suckling cow herds (72.7%).

Conclusions

There is a serious clinically inapparent MAP reservoir in the Swiss cattle population. PCR cannot replace culture to identify individual MAP shedders but is suitable to identify MAP-infected herds, given that the amount of MAP shed in feces is increasing in diseased animals or in animals in the phase of transition to clinical disease.