Fishing effort redistribution in response to area closures

Spatial fishery closures will induce fishing effort to either move to open areas or to cease to fish. When designing a short- or long-term closed area management regime, the expected impact of that closure will depend upon how that effort is redistributed. We present a redistribution model based upon Ideal Free Distributions (IFDs) which is intermediate in complexity between analyses in which effort is distributed uniformly over open areas and models of full fleet dynamics. The IFD models incorporate the fundamentals of the decision process invoked by fishers facing relocation and the ensuing catch rates that result from the addition or removal of effort. Two classes of models were tested: an Availability model where catch rate declines were proportional to abundance; and an Abundance model where abundance declines at an exponential rate with the entry of displaced effort into an area. Results of these models were compared with uniform and proportional redistribution methods. The IFD-based methods included relative cost of relocation, thereby illustrating the importance of both catch rates and movement costs in designing closed area regulations. To demonstrate the methods, hypothetical area closures to United States pelagic longliners in the western Atlantic were examined and the impact of those closures on bycatch rates was evaluated. Guidance for selecting an appropriate model structure for a particular closed area problem is given.     

集思广益拓展禽病防控策略——第58届西方禽病会议内容精选

2009年5月22～25日,第58届西方禽病会议在美国加利福尼亚州萨卡拉门托市举行.该会议每年在美国定期举行,参会代表是来自全球的禽类健康专家.     

Available (ileal digestible reactive) lysine in selected cereal-based food products

True ileal total lysine digestibility was determined and compared with true ileal reactive lysine digestibility when applied to 20 cereal-based breakfast foods. Semisynthetic diets each containing a breakfast cereal as the sole protein source were formulated and fed to growing rats. Titanium dioxide was included as an indigestible marker. Digesta were collected from the rats and total (conventional amino acid analysis) and reactive (guanidination) lysine were determined in both diets and digesta. The true ileal reactive lysine digestibility ranged from 53 to 108% and was significantly higher than the true ileal total lysine digestibility for most of the breakfast cereals. Available lysine content (digestible reactive lysine content) ranged from 0.21 to 3.5 g/kg across the breakfast cereals. The conventional measure of digestible total lysine content significantly overestimated (on average 37%) available lysine for the majority of the cereals. Breakfast cereals undergo a significant degree of lysine modification probably as a result of processing during manufacture.     

The occurrence and significance of Campylobacter jejuni in man and animals

Campylobacter jejuni, which is now recognized as a discrete species, is a gram negative, microaerophilic, thermophilic, nalidixic acid sensitive, hippurate positive pathogen requiring special selective media for propogation. The organism is widely distributed in avian species, experimental and companion animals and in humans. Mammalian campylobacteriosis is characterized by an enterocolitis of variable severity. The prevalence of the condition is relatively high in young individuals, in underdeveloped countries and in subjects with diarrhea. Food animals, especially poultry, are reservoirs of the organism and infection occurs following consumption of untreated surface water, unpasteurized milk, incompletely cooked meat or other contaminated food products. Close contact with infected immature companion animals is a significant cause of campylobacteriosis in children and direct intrafamilial transmission and occupational infection have been documented. Campylobacteriosis attributable to C. jejuni is a condition of emerging significance which arises principally from deficiencies in hygiene inherent in the environment and in the food chain which extends from domestic animals to the consumer.     

Prevalence of Campylobacter jejuni in selected domestic and wild birds in Louisiana

Prevalence of Campylobacter jejuni was determined in a selected population of domestic and free-living birds submitted for necropsy to the Louisiana State Veterinary Medical Diagnostic Laboratory. The 445 cases examined included 13 orders of birds and yielded C. jejuni in 45 cases, representing an isolation rate of 10.1%. Prevalence was highest in Galliformes (25.2%), followed by Anseriformes (12.9%) and Columbiformes (8.3%). Only one isolation was made out of 179 Psittaciformes examined. Penner serotypes 1, 2, 4, and 16 were most commonly identified among the C. jejuni isolates. This study emphasizes the importance of Galliformes as reservoirs of C. jejuni. The commonality of these serotypes with isolates derived from humans suggests the zoonotic potential of Galliformes in relation to human campylobacteriosis. The isolation rate of 12.9% in Anseriformes implicates free-living and migratory waterfowl as carriers of C. jejuni. Results confirm that Psittaciformes represent a low risk of C. jejuni infection in humans.     

A preliminary in vivo study on the potential application of e-tracking in poultry using ink printed 2D barcodes

A preliminary study on the potential application of electronic tracking in poultry in vivo has been conducted. The experimental procedure for this study was based on previous in vitro findings (Fröschle et al., 2009) as part of the same research programme. The study consisted of two phases whereby an initial experiment using inkjet printing of 10 × 10 DataMatrix barcodes onto the beaks of broiler chickens in a live commercial setting has been carried out. Results demonstrated very poor percentage of readability after a short period of time. Barcodes deteriorated very rapidly and this was attributed to the physical effects on the barcodes of the actions of the chickens in a commercial environment, together with the inability of the ink to bond to the hard keratinous surface of the beak. In a subsequent part of the study, a number of commercially available ink types were screened, using a predetermined abrasion testing procedure, for their ability to bond to the beak and provide a readable barcode on the beaks following some predetermined graduated physical abrasion.     

大肠杆菌感染可造成严重损失

大肠杆菌感染对世界养禽业造成了重大损失。大肠杆菌是商品家禽肠道中的正常栖居菌 ,并且还是环境中无处不在的 ,但其产毒菌株会引起局部或全身感染 ,结果造成鸡群死亡率增高 ,使商品产蛋鸡和种鸡的产蛋率下降 ;还可使肉鸡的生长率下降 ,胴体质量下降以及加工时废弃率增高     

Evaluation of biosecurity in broiler breeders

The economic impact of management practices designed to limit the introduction of disease into a parent broiler breeder flock (biosecurity) was evaluated using benefit-cost analysis. Equations were developed to quantify the losses resulting from infection with one of four alternative categories of disease representing incremental levels of pathogenicity. Realistic costs and assumed values relating to the probability of infection were used to evaluate the ameliorative effect of three alternative levels of biosecurity. A microcomputer spreadsheet program was used to confirm that expenditure on protective measures can be justified by both the risk of introducing a disease and the magnitude of losses that may occur following infection.     

Using foresight to prepare animal health today for tomorrow's challenges

Foresight has been introduced in Canada in the area of animal health as a process to broaden thinking about the future and inform policy development. Its initial use and evolution through projects and studies over the past decade are described, demonstrating real action in animal health. Despite positive, continuing, and exciting results in animal health policy development, foresight's widespread acceptance and use thus far have been limited. Critical components for success, drawn from the Canadian experience, are described, and recommendations are offered for further action in animal health.