287 research outputs found

    The role of truck wash practices in dissemination of Salmonella and Campylobacter in commercial swine production

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    This study investigated the sources of two foodborne pathogens, Salmonella and Campylobacter in a commercial swine production system. Pathogens were characterized using conventional culture and isolation techniques and antibiograms

    Evaluation of phenotypic and genotypic approaches as predictors of Salmonella strains of clinical and non-clinical origin

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    This study investigated the possible phenotypic and genotypic similarities and differences between Salmonella isolates obtained from swine with clinical salmonellosis to isolates obtained from swine showing no clinical disease. Phenotypic analysis was done by antimicrobial resistance profiling and amplified fragment length polymorphism (AFLP) fingerprinting was employed for genotypic analysis

    Fish-Eating Birds on Catfish Ponds in the Mississippi Delta

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    Catfish acreage in the Mississippi Delta has significantly declined in the past two decades, but cormorant density on catfish ponds has remained the same. One possible explanation is that there are fewer cormorants in the region, and this is supported with decreasing roost counts. Cormorant roost harassment can be even more effective today than in the past, because there is less aquaculture acreage to protect and fewer cormorants to move. Roost harassment is important over the entire winter, but even more so around mid-January when cormorant abundance is greatest and when cormorants are more focused on aquaculture ponds. The addition of limited lethal management on ponds and roosts may make dispersal efforts more effective. Understanding which ponds fish-eating birds decide to use is important for effective management at catfish farms. Many pond characteristics influence use by cormorants, herons, and egrets. What is in the pond and what is around the pond are things these birds take into consideration. From this work, it is possible to produce a “heat map” of farms showing the probability that each bird species will use a given pond (Figure 6). Paying more attention to ponds with higher probabilities of damage may help bird harassment efficiency on the farm and reduce depredation

    Evaluation of Moderate and Low-Powered Lasers for Dispersing Double-Crested Cormorants from Their Night Roosts

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    The double-crested cormorant (Phalacrocorax auritus) is the primary avian predator on the southern catfish industry, estimated to cause $5 million in damage per year. To date, the most effective strategy for alleviating cormorant depredations in areas of intensive catfish production is coordinated dispersal of cormorant night roosts with pyrotechnics. Many of these night roosts are located in waterfowl refuges or wetland habitat leased for waterfowl hunting. Thus, there is an increasing concern about the effects of cormorant harassment efforts on waterfowl and other wildlife inhabiting these sites in cypress-swamp habitat. To address the need for a roost harassment device that was more species-specific, we evaluated two commercially available low- to moderate-powered lasers in a series of large-pen and field trials for their effectiveness in moving cormorants from test ponds and dispersing cormorants from their night roosts, respectively. In pen trials, laser beams directed at small groups of captive birds produced negligible effects, suggesting that the laser light was not highly aversive. This was consistent with a series of veterinary investigations suggesting no detectable ocular damage to cormorant eyes directly exposed to a selected laser at varying distances down to 1 m. During field trials both lasers, directed at roost trees after sunset, were consistently effective in dispersing cormorants in 1 to 3 evenings of harassment and is comparable to the harassment effort needed with pyrotechnics. Because laser treatment is completely silent and can be directed selectively at cormorants, these devices may be extremely useful for dispersing cormorants in sites where disturbance of other wildlife is a concern. Advantages and disadvantages of lasers relative to pyrotechnics are discussed

    Efficacy of afoxolaner against Dermacentor variabilis ticks in dogs

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    AbstractEfficacy of afoxolaner, a novel isoxazoline insecticide/acaricide, against Dermacentor variabilis ticks was confirmed in two laboratory studies. Each study utilized a controlled, randomized block design. One day prior to treatment, beagle dogs were infested with 50 unfed adult ticks. Repeat infestations were performed weekly for four weeks. The number of live ticks remaining on each dog was determined 48h after treatment and after each subsequent infestation. A single oral treatment with a dose approaching the minimum effective dose of afoxolaner (2.5mg/kg) eliminated the pre-existing infestations by D. variabilis ticks and controlled weekly re-infestations with 99.7–100% efficacy up to Day 23 and >97% efficacy at Day 30

    A review of the evolution of robotic-assisted total hip arthroplasty.

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    INTRODUCTION: Total hip arthroplasty (THA) is currently a very successful operation but continues to evolve as we try to perfect techniques and improve outcomes for our patients. Robotic hip surgery (RHS) began with the 'active' ROBODOC system in the 1980s. There were drawbacks associated with the original ROBODOC and most recently, the MAKO robot was introduced with early promising results. AIM: The aim of this paper is to provide an up-to-date review surrounding this area and discuss the pros and cons of this technique. METHODS: A literature review searching Medline, Embase, Ovidsp, Cochrane library, pubmed database and google scholar was performed searching keywords including: 'Robotic hip surgery', 'Robotic orthopaedic surgery', 'Computer assisted hip surgery', 'robotic arthroplasty', and 'computer assisted orthopaedic surgery'. CONCLUSION: Robotic hip surgery aims to tackle the limitations of the human factor in surgery by promising reproducible and reliable methods of component positioning in arthroplasty surgery. However, as orthopaedic surgeons, we must critically appraise all new technology and support the use providing there is sound robust evidence backing it

    Estimating Waterbird Abundance on Catfish Aquaculture Ponds Using an Unmanned Aerial System

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    In this study, we examined the use of an unmanned aerial system (UAS) to monitor fish-eating birds on catfish (Ictalurus spp.) aquaculture facilities in Mississippi, USA. We tested 2 automated computer algorithms to identify bird species using mosaicked imagery taken from a UAS platform. One algorithm identified birds based on color alone (color segmentation), and the other algorithm used shape recognition (template matching), and the results of each algorithm were compared directly to manual counts of the same imagery. We captured digital imagery of great egrets (Ardea alba), great blue herons (A. herodias), and double-crested cormorants (Phalacrocorax auritus) on aquaculture facilities in Mississippi. When all species were combined, template matching algorithm produced an average accuracy of 0.80 (SD = 0.58), and color segmentation algorithm produced an average accuracy of 0.67 (SD = 0.67), but each was highly dependent on weather, image quality, habitat characteristics, and characteristics of the birds themselves. Egrets were successfully counted using both color segmentation and template matching. Template matching performed best for great blue herons compared to color segmentation, and neither algorithm performed well for cormorants. Although the computer-guided identification in this study was highly variable, UAS show promise as an alternative monitoring tool for birds at aquaculture facilities

    Double-crested Cormorants

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    The history of conflict between double-crested cormorants (Figure 1) and human interest in fisheries is long and convoluted. Following a low point in the 1970s, populations of cormorants expanded in North America, as did concerns about impacts on fisheries. By the late 1990s, natural resource agencies in 27 states reported losses of free-ranging fish stocks to cormorants. Agencies in 10 states, ranging from the Southwest to the Northeast, considered cormorant predation to be of moderate to major concern to fishery management. Overall, double-crested cormorants are not major consumers of commercial and sportfish species. However, exceptions have been recorded at specific sites with documented impacts on local fisheries (see Damage to Fisheries section). Cormorants often congregate and can have significant local impacts where high concentrations of fish occur, such as stocking release sites, private fishing ponds, aquaculture ponds, reservoirs, spawning sites, and other areas. Cormorants may be managed whenever their damage justi-fies the granting of the permits necessary to control them. Adult cormorants eat approximately 19 ounces of food per day, so local impacts of large flocks on fisheries can be substantial. Although cormorants frequently are blamed for reductions in fish harvests, this is not always substantiat-ed. Sometimes other factors, such as pollution, invasive species, and habitat loss may be the primary factor or con-tributing factors in the decline of fisheries

    Piscivorous Bird Use of Aquaculture and Natural Water Bodies in Mississippi

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    Double crested cormorants (Phalacrocorax auritus) and great egrets (Ardea alba) have an extensive history of human wildlife conflict with the aquaculture industry of western Mississippi, USA, due to their depredation of cultured catfish (Ictalurus spp.). Although aquaculture is abundant, western Mississippi also contains naturally occurring water bodies that offer alternative forage opportunities to these species. How cormorants or egrets distribute themselves among these 2 foraging options is unknown, but it has been generally assumed each species uses aquaculture disproportionately more because of the high density of available prey. To test this assumption, we surveyed these species on aquaculture and naturally occurring water bodies using aerial surveys from October through April of 2015–2016, 2016–2017, and 2017–2018. We modeled the proportion of each species on aquaculture as a function of year, date, and weather-related variables using quasi binomial generalized linear models. Egrets used aquaculture consistently more than what was proportionally available to them and use was not influenced by any of the variables we measured. Proportional use of aquaculture by cormorants was lowest during October through January but steadily increased through April, indicating a distribution shift toward aquaculture in the months immediately prior to their migration. The highest proportional use of aquaculture by cormorants occurred in 2016, a year when lethal control measures were not allowed against cormorants. Conversely, the least proportion of cormorants on aquaculture was in 2015 when cormorants could be lethally controlled under authority of an Aquaculture Depredation Order. This trend highlights the potential influence of changes in mortality risk, caused by changes in policy regarding lethal take of cormorants, on cormorant distribution between foraging option
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