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1.
Current trends in screwworm myiasis in the Caribbean region   总被引:1,自引:0,他引:1  
In a random sample of animal producers and animal health personnel, 33% of the respondents in Trinidad, 15% in Guyana, 11% in Suriname and 9% in Jamaica recalled at least one case of human myiasis due to Cochliomyia homivorax (Coquerel). During 1981, respondents in Surinam (88%), Jamaica (90%), Guyana (85%) and Trinidad and Tobago (82%) found at least one case of myiasis in their livestock, occurring mainly in cattle, pigs and dogs. Feral animals, e.g. jaguars, were also found to be infested. The initial wounds were mainly the umbilicus of neonates, and arbitrary wounds, and vampire bites were also affected. Fifty-three to 78% of all respondents examined their livestock daily for wounds and infestation by the screwworm. Annual estimates of losses (in U.S. dollars) due to surveillance and medication ranged from $4.82 to $10.71 per animal. Nationally, these losses amount to $0.30 million (Surinam), $1.02 million (Trinidad and Tobago), $4.33 million (Guyana) and $6.78 million (Jamaica). Figures for other losses, arising from failure to thrive, reduction in milk production and hide injury due to screwworm activity were not available. Most producers found that the greatest screwworm infestation occurred in the wet season, and most described it as second in importance to Boophilus spp. ticks as a pest of livestock, but of greater significance than biting flies, such as tabanids and stable flies. Eradication of the screwworm from the islands of Jamaica and Trinidad and Tobago can be recommended, but in Surinam and Guyana eradication seems feasible only on the 100-km wide coastal strips where most human and livestock populations exist.  相似文献   

2.
Economic impact of poisonous plants on the rangeland livestock industry   总被引:1,自引:0,他引:1  
Poisonous plants on rangelands cost producers and consumers upwards of $250 million annually in the U.S. These costs are attributable not only to livestock deaths and diminshed productivity related to plant poisoning, but also to the management costs associated with usage of forage in areas infested with poisonous plants. At present, even relatively small losses from plant poisoning can cause financial and economic impacts that threaten range enterprises, particularly those using public lands.  相似文献   

3.
In grazing systems, heterogeneous distributions of forage resources and faeces result in localised accumulations of nutrients and parasites (both macroparasites and microparasites), creating trade-offs between the costs of exposure to infestation or infection and the benefits of nutrient intake. Each contact between livestock and faeces in the environment is a potential parasite/pathogen transmission event. Thus, herbivores must make foraging decisions in complex environments which will affect their intake of both nutrients and parasites. However, the pattern of forage and faecal resources in agricultural environments will also be affected by the grazing management system in place. The aim of this study was to investigate the effect of grazing management on the risk of infection/infestation to livestock. We used a spatially explicit individual based stochastic foraging model to simulate livestock contact (both grazing and investigative) with faeces in the environment. The model was parameterised to simulate cattle grazing under three types of grazing management: set stock (i.e. where sward growth and cattle intake are in equilibrium in a single field); a two pasture rotation grazing system with increasing number of rotations; and a rotational grazing system with two rotations and increasing subdivisions of the pasture. Overall the amount of cattle contact with faecal-contaminated patches was similar in both set stocking and rotational grazing scenarios, suggesting no difference in the risk of infection or infestation between the different systems. However, the timing and absolute amounts of peak contact varied greatly indicating that different grazing management systems expose livestock to risks of different types of parasites at different times of the grazing season. Intensive rotational systems with small pasture blocks (especially the first grazing period) maximised livestock contact with fresh faeces, and thus exposure to microparasites (e.g. bacterial pathogens). Livestock re-entering pasture blocks in rotational systems and set stocked livestock had the highest contact with old faeces and thus have a greater risk of macroparasite transmission (gastrointestinal nematodes). This study highlights how livestock management affects the highly dynamic interaction between livestock and distributions of parasites in the environment and thus the levels of livestock exposure to parasites and pathogens via the faecal–oral route.  相似文献   

4.
陕西知识密集型草业的实践与展望   总被引:1,自引:1,他引:0  
随着退耕还林还草及农业结构调整战略的实施,陕西知识密集型草业取得了长足发展,1997年以来,全省每年人工种草都在20万hm2以上,建立牧草种子繁殖基地0.67万hm2,牧草种子包衣处理、旱作种草等先进技术进一步推广应用.封山禁牧、设施养畜全面推行,草地保护工作进一步加强,并形成了以草兴畜、以畜促草、草畜联动等草业发展特点.  相似文献   

5.
Wild pigs are a free-ranging invasive species capable of inflicting significant damage on rural property. Wildlife management personnel may benefit from understanding the negative societal impact of wild pigs. A statewide mail survey of randomly selected landowners was conducted in rural Tennessee counties known to have wild pigs. The economic value of damage caused by wild pigs in 2015 in these counties was estimated at $26.22 million, whereas the cost incurred in control and eradication was $2.09 million. Input-output modeling of damage in these counties on the state’s economy showed $32.8 million in lost industrial output, $4.6 million in lost labor income, and 332 jobs or job equivalents affected. Findings are useful in understanding the types of damage, and the extent of these impacts on the rural economy. They could also facilitate comparing the expected benefit with the cost of control programs in Tennessee and comparable areas facing similar invasions from wild pigs.  相似文献   

6.
On the basis of questionnaire surveys and personal interviews with veterinarians, ranchers, and livestock farm advisors, the seriousness of anaplasmosis in California was determined. In 1976, the economic loss due to anaplasmosis in the study sample of beef cattle was $2,203,150. When inferences were made from the sample population to include the whole population of beef cattle, this loss was estimated to be $5,244,319. These values were in contrast to a farm advisors' estimate of $11 million loss due to anaplasmosis, which was included in a total estimated loss of $300 million due to all livestock diseases of economic importance in California. It appeared that anaplasmosis, although having a substantial economic impact in California, is not as economically devastating as it was once thought to be. It was concluded that private programs currently in use (vaccination and treatment) are sufficient to control anaplasmosis.  相似文献   

7.
The objective of this study was to estimate the direct economic losses due to the condemnation of the liver and large intestine because of internal diseases (multifocal necrosis in the liver (MNL) and inflammation of the large intestine (ILI)), and the indirect losses because of reductions in carcass performance from MNL, bovine abdominal fat necrosis (BFN) and ILI using data from 5383 Japanese Black cattle. Direct losses were estimated by multiplying the price of the condemned part by the frequency of its occurrence owing to the disease. Similarly, indirect losses were estimated as the product of unit carcass price and reduction in carcass weight (CW) due to the disease. The direct impact on the beef cattle industry from MNL and ILI was estimated at around $1.29 million (US$1 = ¥120) per year. A least‐squares analysis showed that MNL had no influence on any carcass trait, whereas BFN and ILI significantly reduced CW, rib eye area and darkened the beef. ILI also reduced rib thickness. The indirect losses from BFN and ILI were estimated as a maximum of $131.7 and $256.4 per animal and around $6.26 million and $4.03 million for the industry, respectively, mostly because of the reduction in CW.  相似文献   

8.
Substantial gaps exist between weed management researchers and practitioners with respect to prompt exchange of knowledge between the two groups, hindering the implementation of effective management to solve weed problems. We conducted a survey between 2016 and 2018 among weed management practitioners (n = 259) across diverse ecoregions on California rangelands and collected essential information from practitioners for bridging the research-implementation gap. The information included management costs, high-priority weeds, and spatial scales and temporal changes in weed management. The management cost had a mean of $5.12 ha−1yr−1 with a large variance implying the uncertainty of this information. The percentage of annual budget dedicated to weed management explained about 30% of the variation in this cost. Moreover, this annual per-unit area cost decreased with increasing management area. The average size of rangeland managed by survey respondents was 1 256 ha. The top three high-priority weeds statewide were yellow starthistle (Centaurea solstitialis), medusahead (Taeniatherum caput-medusae), and all thistles combined. Medusahead and some thistle species remained on the top list in each ecoregion. Respondents overwhelmingly (80.9%) noted changes in weed problems in the past 5−10 yr, specifically citing greater weed pressure and changes in weed species. A significantly higher proportion of respondents from agencies and private businesses reported changes in weed problems than those from universities and nongovernmental organizations (NGOs), further underscoring the gap between practitioners and researchers. A majority of the respondents (75.3%) indicated the record-setting California drought had a negative effect on weed management, reducing treatment efficacy and favoring weeds over desirable species. Overall, our findings illustrate increasing challenges in weed management on California rangeland. These challenges call for adaptive management-research programs to increase cost-effectiveness of weed management and to swiftly and effectively respond to dynamic weed problems on large spatial and long temporal scales.  相似文献   

9.
农田草地系统耦合生产分析   总被引:11,自引:3,他引:11  
张英俊 《草业学报》2003,12(6):10-17
国家科技部对未来15年畜牧业发展技术提出战略政策。指出要加大草原保护力度,合理开发1333.3万hm^2南方草山草坡及4000万hm^2农牧交错带。据此,农田草地系统耦合将成为我国家庭承包经营制农业的主要生产方式,尤其是农牧交错带和我国南方地区。分析农田草地系统耦合生产模式,管理核心是减少农田和草地系统营养物质的外流损失。生产的关键技术有草田轮作技术,农田作物秸秆再利用技术,家畜宿营技术和全日制放牧技术。  相似文献   

10.
OBJECTIVE: To establish the cost to the Queensland dairy industry of cattle tick infestation and its control, excluding the costs incurred from control measures directed specifically at tick fever and morbidity and mortality arising from tick fever. STUDY DESIGN: Economic models are described that have been based on empirical data relating to liveweight and milk yield loss, and on a survey of control practices and tick infestation. The first two models were designed to estimate costs of control and losses resulting from tick infestation on a single dairy farm. The third model developed estimates of the cost of tick infestation for each of four regions within the tick-infested area of Queensland. RESULTS: The overall cost to the Queensland dairy industry of the cattle tick (excluding the costs associated specifically with tick fever) and based on 1998 management practices, was $4,096,000 per annum. About 49% of this cost was related to the costs of control and 51% to losses in production. CONCLUSION: Cattle tick infestation represents a significant impost on dairy producers in Queensland, and although the actual cost will change as deregulation results in economic changes in the industry, infestations of ticks will continue to be expensive to control.  相似文献   

11.
稗属植物种质资源及应用价值研究进展   总被引:2,自引:0,他引:2  
稗属(Echinochloa)植物是一种繁殖力强、生态适应性广的草本植物,在全世界均有大面积分布,因其危害多种农作物的生长,过去多把稗属植物看作恶性杂草来研究。稗属植物除作为杂草外,还具有很高的饲用价值,其营养丰富,草质柔嫩,适口性好,是发展绿色畜产品的新型优质牧草。本文综述了稗属植物种质资源分布和系统进化的研究概况,从形态学水平、细胞学水平、生化水平和分子水平上总结了稗属植物遗传多样性的研究进展,并着重介绍了稗属植物的经济价值和优良基因的利用。分析了我国稗属植物种质资源研究存在的问题及发展前景,指出今后应加强对稗属植物种质资源搜集、分类、遗传多样性、基因组学的研究和饲用稗草的开发利用。  相似文献   

12.
Forage-animal production agriculture is implementing infrastructure changes and management strategies to adjust to increased energy-related costs of fuel, feed grains, fertilizers, and seeds. The primary objectives of this position paper are to assess future research and extension scientific needs in forage utilization, financial support for the discipline, and changing status and number of scientists. A survey questionnaire returned from 25 land-grant universities in the eastern half of the United States rated the top 4 research needs as 1) pasture systems and efficiency of production; 2) interfacing with energy concerns; 3) forage cultivar evaluations and persistence; and 4) environment impacts. Plant-animal future research needs at 11 USDA-ARS regional locations are targeted at sustainable management and improved livestock performance, ecophysiology and ecology of grasslands, environment impacts, and improved technologies for nutritive value assessments. Extension scientists from 17 southern and northeastern states listed the top 3 needs as forage persistence, soil fertility and nutrient management, and pasture systems and efficiency of production. Grant funds currently provide more than 40% of land-grant university research and extension efforts in forage utilization, and scientists estimate that this support base will increase to 55 to 60% of the funding total by 2013. Reduced allocation of state and federal funding has contributed to a reduction in the number of full-time equivalent (FTE) scientists engaged in forage utilization research and extension activities. The current 25 state FTE conducting research number about 2.8 per state. This includes 10 states with >3, 11 states with <2, and 3 states with <1 FTE. Increased interest in cellulosic energy, climate change, and environmental impact may offer new opportunities for these FTE to participate in integrated cross-discipline research Extension programming, and technology transfer methods will change to accommodate reduced funding but with increasing numbers of novice, recreation-oriented landowners.  相似文献   

13.
Losses from morbidity and mortality due to anaplasmosis were assessed in beef and dairy cattle of the Red River Plains and south-east areas of Louisiana. The cost of treatment and prevention of anaplasmosis and losses in milk production and those due to deaths or culling were valued at $0.5 million for the year 1983 in these two areas. The cost of prevention included the use of tetracyclines in feed and salt-mineral supplements, injectable tetracycline, vaccination and an estimated 10% of the cost of insecticidal ear tags, sprays, pour-on applications and dust bags. The remainder of these costs and the total cost of vector control in dairy cattle was attributed to the control of fly annoyance. Treatment costs included veterinary fees and the owner's treatment costs, including labour costs.  相似文献   

14.
王建兵  张德罡  田青 《草原与草坪》2013,33(1):54-58,64
在半农半牧地区,草原资源家庭责任承包制的实施使土地被过分细分到户,导致草地的破碎化。研究表明:强化草原管理有利于以草定畜,严格控制牲畜饲养量,草地超载及代牧现象减少;畜种改良使得传统的草原放牧向半放牧半舍饲过渡,大牲畜的饲养量出现大幅度减少;草地破碎化使得草地退化以定居点和水源为中心,沿着牧道呈一定的梯度形成辐射状的区域性草地退化趋势。通过草地的联户承包,共同经营管理,促进了草畜平衡制度的顺利实施,一定程度上解决了草畜矛盾,减缓了草原生态恶化的趋势。  相似文献   

15.
The New World Screwworm (NWS, Cochliomyia hominivorax) is an obligate parasite of warm-blooded animals. The female lays up to 300 eggs in any break in the skin, and the resulting larvae (screwworms) burrow into surrounding living flesh. Infested animals frequently die, while the annual cost of controlling the pest in domestic animals is about US $10 per head. NWS is endemic in tropical Latin America. In 1988, it was detected in Libya, presumable introduced with imported sheep. By 1990, the infestation had spread to an area of 25,000 km2 containing some 2 million livestock. In early 1991, an internationally funded eradication programme was undertaken by FAO, using sterile insects. Each week, 40 million pupae were flown from a production plant in Mexico, and the emerged adults were distributed by over the infested area. Within a few months, the infestation has been eradicated. Whereas 12,000 infested animals were found in 1990, only 6 were detected in 1991. The programme involved the shipping and distribution of 1.3 billion sterile insects, animal inspections totalling 40 million and laboratory examination of 280,000 trapped flies. While the programme cost close to US $75 million, a benefit/cost ration of 50:1 has been estimated.  相似文献   

16.
The risk of a disease occuring is often more difficult to estimate than estimating a monetary value of the losses sustained when the disease occurs. The probability of a non-infested island in the Lesser Antilles becoming infested with Amblyomma variegatum was integrated into the formula for calculating the present value of the benefit of avoiding the costs of infestation by the tick. Based on the history of the spread of A. variegatum in the Caribbean, the probability of becoming infested was estimated to be one island or island group per year and the tick needed 5 years to spread over a 15-km area from an initial point of infestation. This rate of spread is slow compared with that of Boophilus microplus, which spread over the 160-km long island of Puerto Rico in <4 years.  相似文献   

17.
Twenty-nine California dairy herds were studied over a 12-month period from 1988 to 1989 as part of the National Animal Health Monitoring System. Monthly interviews administered to dairy producers were used to measure the costs of all health-related expenditures and disease incidence in these herds. Of the total $1,523,558 reported, $1,355,467 (89%) was attributed to cost of disease events and $168,091 (11%) to cost of disease prevention. Most (78%) of the cost of disease events was attributable to death and culling losses. Veterinary services accounted for only $54,099 (4%) of total costs, 64% of which was used for disease prevention, compared with 36% for disease treatment. Udder disease was the most costly category of diseases reported at an average of $49.85/head at risk annually, followed by reproductive problems at $38.05. Through the use of sampling strategies less biased than those used in other surveys, the National Animal Health Monitoring System is designed to provide statistically-valid estimates of disease incidence and costs across broad geographic areas, potentially benefiting all those interested in the economics of livestock diseases in the United States.  相似文献   

18.
化除宿营法建植人工草地产草量高,建植第2年最高干物质产量达到23 270 kg/hm2。化除宿营法与化除免耕法建立人工草地在建植当年没有显著差异,但第2年化除宿营法比化除免耕法增产7 353 kg/hm2(P<0.01)。在草地建植当年和第2年,施肥对地上生物量没有明显影响。化除宿营法建立人工草地宿营强度达到4羊夜即可,第2年平均干物质产量达15 483 kg/hm2。在无人为干预的情况下,蒿类等不可食杂草迅速侵入,土壤肥力越高,扩散速度越快;不可食杂草比例超过50%后,草地基本没有利用价值,地上生物量也不再急剧下降。  相似文献   

19.
Johne's disease (JD) is an incurable, chronic infectious disease prevalent in dairy herds throughout the US and the world. The substantial economic losses caused by JD have been well documented. However, information on the costs of controlling the disease is limited, yet necessary, if producers are to make sound decisions regarding JD management. The purpose of this paper is to describe a method for evaluating the cost-effectiveness of management changes to control JD on infected dairy farms. A 5-year longitudinal study of six dairy herds infected with JD was performed. Each herd implemented a JD control program upon study enrollment. Prevalence of JD within each herd was monitored with annual testing of all adult cows using fecal culture and/or serum ELISA. Individual cow production and culling information was collected to estimate the annual economic losses caused by JD. An economic questionnaire was developed and administered to each herd annually to estimate costs directly attributable to the JD control program. Based on the costs of the control program, and using the losses to estimate the potential benefits of the control program, the net present value (NPV) of the control program was calculated for each herd during the study and projected into the future for a total of 20 years. The NPV was calculated for four different scenarios: (1) assuming a linear decline in losses beyond the observed period of the study with JD eradication by year 20 of the control program; (2) assuming losses and JD prevalence remain constant at the rate equal to that of the last observed year while continuing the control program; (3) assuming linear increase in losses at rate equal to that in scenario 1 with no control program; and (4) assuming losses remain constant at same level as the beginning of the study with no control plan implemented. The NPV varied greatly across the herds. For scenario 1, only three herds had a positive NPV; and only two herds had a positive NPV under scenario two. In the absence of a control program, the NPV's were always negative. The costs of the JD control programs implemented on these herds averaged $30/cow/year with a median of $24/cow/year. The annual losses due to JD averaged $79/cow/year with a median of $66/cow/year. Investing in a JD control program can be cost-effective.  相似文献   

20.
An attempt to predict the rate of spread of and economic losses due to Parafiliaria bovicola infections in Swedish cattle was made for a 20-year period using the best epidemiological data available. By 1990, yearly losses in the absence of a control program may amount to 40 million Swedish crowns (8 million U.S.$). The estimated losses were compared to four presumptive eradication measures: (i) pharmaceutical treatment of cows with cutaneous Parafilaria bleeding, (ii) culling of bleeding cows, (iii) indoor management of bleeding cows, and (iv) pharmaceutical treatment of young livestock going to slaughter. Only the first three control programs will theoretically result in eradication of the parasite. The calculated benefit—cost ratios were 30.0, 5.9, 5.9 and 1.9 for (i), (ii), (iii) and (iv), respectively.  相似文献   

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