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1.
The Cornell (8L:10D:2L:4D) and (Ralston Purina) Biomittent lighting programmes were applied to a commercial strain of White Leghorn laying hens from 20 to 64 weeks of age. 2. The egg production of hens exposed to the Cornell lighting was reduced compared to the Bio-mittent programme. 3. Food consumption was less and efficiency of utilisation significantly improved for the Cornell programme during phase I (20 to 36 weeks) of the study. Significant differences were not observed during phase II (37 to 64 weeks) or for the whole cycle (20 to 64 weeks). 4. Body weights were significantly greater for hens exposed to the Bio-mittent programme during both phases I and II. 5. Egg weights, egg mass and egg weight distributions were not different for hens exposed to the 2 programmes. 6. Food costs and the margin of income over food costs were significantly in favour of the Cornell programme during phase I. However, differences for phase II and the complete cycle were not significant. 7. The Bio-mittent programme offered a computed advantage of 14.4% fewer hours of light usage compared to the Cornell programme.  相似文献   

2.
New Zealand has a history of continuous freedom from foot-and-mouth disease and relies on a two-tier system of surveillance to maintain this status. The first involves border control procedures and stringent importation standards, and the second is an exotic disease and pest response programme. As part of an economic evaluation comparing the exotic disease and pest response programme against a hypothetical lower grade ;measured response programme subjective judgements of the risks involved were required. Twenty-eight selected animal health professionals, predominantly veterinarians, were posted a questionnaire that used three techniques (single point estimates, three point estimates and elicitation methods) to determine the risk components in a foot-and-mouth disease outbreak. The two key variables were the probability of an outbreak in New Zealand, and the number of secondary properties to which the disease spread during the epidemic. A Delphi conference of ten selected participants then focused mainly on the two key variables, with a second round postal extension to this group for the first variable. The individual data sets were then analysed and combined using a stochastic simulation technique. The final mean probability of an outbreak was about once in 50 years (0.0199). The mean numbers of farms to which disease would spread during an epidemic under the existing exotic disease and pest response programme, a measured response programme which allowed vaccination and a measured response programme which excluded vaccination were estimated to be 61, 478 and 2230 respectively. The policy implications arising from the quantification of these two key variables are that more expenditure on preparedness is justifiable and current resource planning is barely adequate.  相似文献   

3.
New Zealand has a history of continuous freedom from foot-and-mouth disease and relies on a two-tier system of surveillance to maintain this status. The first involves border control procedures and stringent importation standards, and the second is an exotic disease and pest response programme. As part of an economic evaluation comparing the exotic disease and pest response programme against a hypothetical lower grade “measured response programme” subjective judgements of the risks involved were required. Twenty-eight selected animal health professionals, predominantly veterinarians, were posted a questionnaire that used three techniques (single point estimates, three point estimates and elicitation methods) to determine the risk components in a foot-and-mouth disease outbreak. The two key variables were the probability of an outbreak in New Zealand, and the number of secondary properties to which the disease spread during the epidemic. A Delphi conference of ten selected participants then focused mainly on the two key variables, with a second round postal extension to this group for the first variable. The individual data sets were then analysed and combined using a stochastic simulation technique. The final mean probability of an outbreak was about once in 50 years (0.0199). The mean numbers of farms to which disease would spread during an epidemic under the existing exotic disease and pest response programme, a measured response programme which allowed vaccination and a measured response programme which excluded vaccination were estimated to be 61, 478 and 2230 respectively. The policy implications arising from the quantification of these two key variables are that more expenditure on preparedness is justifiable and current resource planning is barely adequate.  相似文献   

4.
Ireland ran a conventional test and slaughter Bovine Tuberculosis eradication programme from 1954 until 1988. This programme fulfilled our trading requirements but failed to eradicate TB. At this point a major initiative, ERAD, was launched targeted with reducing the disease levels by half within a four-year period and devising the strategy and supports necessary to achieve final eradication. The lessons learned at that time have informed Ireland's eradication programme ever since. Eradication was not possible without developing solutions to address the wildlife disease reservoir and other identified constraints. Since 1992 the programme objectives have been restated. It is now effectively an interim control programme where significant resources have been invested in research and development aimed at overcoming the identified constraints to eradication. Policy is informed by science and debate among stakeholders is generally knowledgeable and balanced. This paper outlines developments in recent years and sets out our expectations for progress in the period ahead.  相似文献   

5.
A compulsory eradication programme for bovine herpesvirus 1 (BHV1) was implemented in the Netherlands in 1998. At the start of the programme, about 25% of the dairy herds were certified BHV1-free. Simulation models have played an important role in the decision-making process associated with BHV1 eradication. Our objective in this study was to improve understanding of model behaviour (as part of internal validation) regarding loss by herds of the BHV1-free certificate. Using a Cox proportional hazards model, the association between farm characteristics and the risk of certificate loss during simulation was quantified. The overall fraction of herds experiencing certificate loss amongst initially certified during simulation was 3.0% in 6.5 years. Factors that increased risk for earlier certificate loss in the final multivariable Cox model were higher 'yearly number of cattle purchased', 'farm density within a 1 km radius' and 'cattle density within a 1 km radius'. Qualitative behaviour of risk factors we found agreed with observations in field studies.  相似文献   

6.
The purpose of this study was to estimate the genetic parameters of biokinematic variables in Spanish Purebred (SPB) horses in order to select those of sufficient interest to be measured in the pre-selection of the animals for possible inclusion in the breeding programme. Kinematic analysis of 130 SPB horses 4.6+/-1.5 years old were recorded at the trot (4m/s) on a treadmill. Genetic parameters were estimated using VCE software and a bivariate mixed animal model including age and stud as fixed effects and animal additive genetic effect and residual error as random effects. In general, heritabilities were high (0.33-0.88). The angular variables presented the lowest heritabilities, whereas the maximum height of the fore-hoof and the duration of swing phase in the hindlimb gave the highest scores. Genetic correlations were also very high, so it was possible to reduce the number of breeding programme characteristics to stride duration, hindlimb swing phase duration, range of stifle and elbow angles, minimal angle of carpus, and minimal retraction-protraction angle of the hindlimb.  相似文献   

7.
Tick and fly control programmes have undergone radical review in recent years. Insecticidal control measures are now often seen as a means of reducing target populations to a level sufficiently low for final eradication by biological or ecological techniques, the sterile male method (SIRM) being particularly favoured. As a preliminary, the new range of insecticidal application techniques includes insecticidal tags, bands, boluses, implants and pheromone baits. The final eradication programme could then involve the use of sterile flies or sterile hybrid ticks, for example. Immunization of cattle against ticks, the use of tick-resistant crossbreeds of cattle, tick-repellent grasses and dung burying beetles are among the additional techniques now being actively investigated.  相似文献   

8.
In 1998, Countdown Downunder, Australia's national mastitis and cell count control programme, was created. With funding from the country's leading dairy organisation, Dairy Australia, this programme was originally intended to run for three years but is now in its tenth year. As it was the first time Australia had attempted a national approach to mastitis control on the farm, the first three years of the programme were largely concerned with the development of resources to be used by farmers and service providers. The second three years were devoted to training with both groups. Since that time, Countdown Downunder has entered into a second resource development phase. The goal of the programme was to achieve a reduction in the bulk milk somatic cell count from the Australian dairy herd. To achieve this, the programme had to develop resources with clear and consistent messages around mastitis and somatic cell count control on farms. It was determined that progress toward the goals would be made more rapidly if service providers were trained in the use of these resources prior to farmers. This paper reviews the Countdown Downunder programme from 1998 to 2007.  相似文献   

9.
This study aimed to determine the effects of weaning age and postweaning feeding programme on pig performance and health. In experiment 1, 96 same gender pairs of pigs weaned at 3, 4 and 5 weeks of age were used in a 3 (weaning age)×4 (dietary programme) factorial design experiment. Pigs received different amounts of a phase 1 diet (16.2 MJ/kg digestible energy (DE) and 16.2 g/kg lysine) and phase 2 diet (15.3 MJ/kg DE and 15.0 g/kg lysine): (A) very low (VL, 1 kg phase 1 and 3 kg phase 2 diet per pig); (B) low (L, 2 kg phase 1 and 6 kg phase 2 diet per pig); (C) medium (M, 3 kg phase 1 and 9 kg phase 2 diet per pig) or (D) high (H, 4 kg phase 1 and 12 kg phase 2 diet per pig), followed by a cereal based phase 3 diet (15.0 MJ/kg DE and 13.8 g/kg lysine) to 10 weeks of age. In experiment 2, faecal samples from 60 pigs weaned at 3, 4 and 5 weeks of age were collected at 10 days postweaning and analysed for Escherichia coli and lactic acid bacteria counts. In experiment 1, there were no interaction effects of age×dietary programme on growth performance. Dietary programme did not affect growth performance from weaning to 10 weeks of age. From weaning to 10 weeks of age, increasing weaning age increased average daily gain (ADG; 363, 402, and 476 g for 3, 4 and 5 weeks respectively; s.e. 17.6; P<0.001), average daily feed intake (ADFI; 560, 620, and 680 g; s.e. 26.1; P<0.001), and improved feed conversion ratio (FCR; 1.57, 1.55, and 1.43; s.e. 0.045; P<0.05). However, weaning age had no effect (P>0.05) on pig weight at 10 weeks of age. In experiment 2, 3 week weaned pigs had higher faecal counts of E. coli (P<0.05) than 4 week weaned pigs and higher faecal counts of lactic acid bacteria (P>0.01) than 5 week weaned pigs at 10 days postweaning. In conclusion, feeding higher amounts of phases 1 and 2 diets did not affect performance at any of the weaning ages tested. Increasing weaning age increased growth performance between weaning and 10 weeks of age, but had no effect on the resulting body weight. Pigs weaned at 3 weeks of age had increased counts of selected faecal bacteria compared to those weaned later.  相似文献   

10.
Economic analyses are indispensable as sources of information to help policy makers make decisions about mitigation resource use. The aim of this study was to conduct an economic evaluation of the Swiss national mitigation programme for bovine viral diarrhoea virus (BVDV), which was implemented in 2008 and concludes in 2017. The eradication phase of the mitigation programme comprised testing and slaughtering of all persistently infected (PI) animals found. First, the whole population was antigen tested and all PI cattle removed. Since October 2008, all newborn calves have been subject to antigen testing to identify and slaughter PI calves. All mothers of PI calves were retested and slaughtered if the test was positive. Antigen testing in calves and elimination of virus-carriers was envisaged to be conducted until the end of 2011. Subsequently, a surveillance programme will document disease freedom or detect disease if it recurs. Four alternative surveillance strategies based on antibody testing in blood from newborn calves and/or milk from primiparous cows were proposed by Federal Veterinary Office servants in charge of the BVDV mitigation programme. A simple economic spreadsheet model was developed to estimate and compare the costs and benefits of the BVDV mitigation programme. In an independent project, the impact of the mitigation programme on the disease dynamics in the population was simulated using a stochastic compartment model. Mitigation costs accrued from materials, labour, and processes such as handling and testing samples, and recording results. Benefits were disease costs avoided by having the mitigation programme in place compared to a baseline of endemic disease equilibrium. Cumulative eradication costs and benefits were estimated to determine the break-even point for the eradication component of the programme. The margin over eradication cost therefore equalled the maximum expenditure potentially available for surveillance without the net benefit from the mitigation programme overall becoming zero. Costs of the four surveillance strategies and the net benefit of the mitigation programme were estimated. Simulations were run for the years 2008-2017 with 20,000 iterations in @Risk for Excel. The mean baseline disease costs were estimated to be 16.04m CHF (1 Swiss Franc, CHF=0.73 € at the time of analysis) (90% central range, CR: 14.71-17.39m CHF) in 2008 and 14.89m CHF (90% CR: 13.72-16.08m CHF) in 2009. The break-even point was estimated to be reached in 2012 and the margin over eradication cost 63.15m CHF (90% CR: 53.72-72.82m CHF). The discounted cost for each surveillance strategy was found to be smaller than the margin, so the mitigation programme overall is expected to have a positive net economic benefit irrespective of the strategy adopted. For economic efficiency, the least cost surveillance alternative must be selected.  相似文献   

11.
Extract

When I was invited to give a paper at this conference I was also sent a draft of the scientific programme. I was not particularly surprised to find that most of the programme was of little direct interest to me. This has been the case for several years. There has also been only a small contribution from research scientists at Wallaceville over the same period. I can only surmise that the sort of work that we are doing is, by and large, of no interest to the bulk of the veterinary profession in New Zealand. And yet, when I first started at Wallaceville more than twenty years ago, we would have provided at least 50 percent, and on occasion more,of the scientific programme.  相似文献   

12.
For the production of slaughter pigs under large-scale conditions, it is important to know the basic economic features of all links in the whole production chain and also the distribution of the total profit in relation to the amount of work involved in individual production sections. The economic evaluation of the production of the final hybrids through the various stages of the hybridisation programme is very valuable. This type of detailed economic examination has shown substantial room for improvement in the process and a large return on investment put into this area. This follows from the number of final hybrids (729) and from the total weight of slaughter pigs (80 190 kg) produced per sow in an elite herd.For example, under Czechoslovakian conditions, doubling the investments of sow breeding in elite herds (the increased initial price of sows, the increased intensity of breeding work connected with higher selection intensity, etc.) is fully compensated by an increase in the growth rate of hybrids during fattening of about 5 grams per pig per day (e.g. from 600 g to 605 g) without regard to changes in other performance characters.For the evaluation of individual performance characters, the profit functions were constructed and their use in the selection of possible combinations of crossing for final hybrid production was also shown.The objective knowledge of economic relations and functions in the production of slaughter pigs is thus becoming essential for the management of the whole pig industry.  相似文献   

13.
Salmonella in pork can be combated during pre- or post-harvest. For large slaughterhouses, post-harvest measures like decontamination might be cost-effective while this is less likely with small-to-medium sized slaughterhouses. In this study, pre-harvest measures might be more relevant. We describe an extended surveillance-and-control programme for Salmonella in finisher pigs, which, to establish equivalence to the Swedish control programme, is intended for implementation on the Danish island, Bornholm. The effect of the programme on food safety was estimated by analysing Salmonella data from pig carcasses originating from herds that would have qualified for the programme during 2006-2008. Food safety was interpreted as prevalence of Salmonella on carcasses as well as the estimated number of human cases of salmonellosis related to pork produced within the programme. Data from the Danish Salmonella programme were obtained from Bornholm. We used a simulation model developed to estimate the number of human cases based on the prevalence of Salmonella on carcass swabs. Herds are only accepted in the programme if they have one or less seropositive sample within the previous 6 months. In this way, the Salmonella load is kept to a minimum. The programme is not yet in operation and pigs that qualify for the programme are currently mixed at slaughter with those that do not qualify. Therefore, we had to assess the impact on the carcass prevalence indirectly. The prevalence of Salmonella in carcass swabs among qualifying herds was 0.46% for the 3?years as a whole, with 2006 as the year with highest prevalence. According to the simulation the expected number of human cases relating to pork produced within the programme was below 10. When the programme is in operation, an extra effect of separating pigs within the programme from those outside is expected to lower the prevalence of Salmonella even further.  相似文献   

14.
The aim of this study was to determine the influence of a 10-month training programme on the linear, temporal and angular characteristics of the fore and hind limbs at the trot in the Andalusian horse, using standard computer-aided videography. Sixteen male Andalusian horses were observed before and after training. Six strides were randomly selected for analysis in each horse and linear, temporal and angular parameters were calculated for fore and hind limbs. The training programme used here produced significant changes in kinematic parameters, such as shortening of stride length, and increase in swing duration and a decrease in hind limb stance percentage. No significant differences were recorded in the angular values for the forelimb joints. In trained horses, the more proximal joints of the hind limb, especially the hip and stifle, had a greater flexion while the fetlock showed a smaller extension angle. At the beginning of the swing phase, hip and stifle joints presented angles that were significantly more flexed. When the hind limbs came into contact with the ground, all the joints presented greater flexion after training.  相似文献   

15.
A new veterinary service to promote ongoing, incremental improvements in the risk management of mastitis and milk quality was developed between 2005 and 2008. This was designed to enhance the relationship between the farmer and advisor, as an extension of the Countdown Downunder programme, Australia's national mastitis and milk quality programme. This service was co-developed between the Countdown Downunder programme team and a core development group of veterinarians involved with trialling the service, and farmers and social researchers. The service, known as Countdown MAX, involved advisory input at the planning stage, a written risk management plan, multiple engagements between the farm team and advisor for tracking and re-planning, and a service fee. Risk management resources (modules) were developed to be employed at the drying-off and calving periods, and during lactation. During the development and implementation phase eight veterinary practices conducted Countdown MAX consultations on 55 farms. Eighty-eight Countdown MAX modules were delivered in total, with 55% of farms completing more than one module but only 38% of modules reviewed successfully. A social research project examined the implementation of the Countdown MAX service in participating veterinary practices during the development phase. Findings of the project were that the successful uptake of a new mastitis service into a veterinary practice was enhanced through uptake by practice owners of the concept, the formation of a written practice plan, adequate communication and explanation of the new service to all staff, logistical support for the service within the practice, and transfer of mastitis expertise within the practice.  相似文献   

16.
Actinobacillus pleuropneumoniae, grown in batch culture, was provided with pyridine nucleotides at concentrations that limited the final growth yield (pyridine nucleotide-deficient cultures) or did not determine the final extent of growth (pyridine nucleotide-sufficient cultures). Sarkosyl-extracted outer membranes from stationary phase, pyridine nucleotide-sufficient organisms contained 23,000 Mr and 43,000 Mr polypeptides that were absent (23,000 Mr) or barely detectable (43,000 Mr) in outer membranes from stationary phase, pyridine nucleotide-deficient organisms or exponential phase organisms. When growth ceased due to exhaustion of pyridine nucleotide, the ratio of the major outer membrane polypeptides (31,000, 38,000 and 69,000 Mr) was altered, becoming more like the ratio found with exponential phase organisms. Similar results were obtained when growth ceased due to glucose exhaustion at low biomass concentrations demonstrating that diverse nutrient deprivations can induce similar changes in outer membrane protein profile. All of these polypeptides were recognized by porcine immune sera indicating their production by A. pleuropneumoniae growing in vivo.  相似文献   

17.
The oral rabies vaccination (ORV) programme is the most widespread vaccination programme that is implemented in the European Union and targets wildlife diseases. The size of the project requires significant financial resources, so a cost–benefit analysis is necessary to establish the economic value of the project. We summarized all ORV costs during the period 2011–2016 in Croatia, calculated all established benefits and presented the cost–benefit ratio (CBR). Additionally, we analysed all components included in the ORV and rabies control programme (surveillance, preventive human treatment and vaccination of dogs) to find possibilities to increase the benefits. According to our results, in the period 2011–2016, the CBR was only 0.05, and the majority of the cost was derived from the preventive vaccination of dogs (72.3%). With the implementation of 2‐ or 3‐year vaccination intervals, the CBR can be increased to 1.46 or 1.92, respectively, confirming positive economic value. This study shows the importance of analysing all rabies control and eradication components based on the specific characteristics of a particular country to determine the factors that can be modified to potentially improve the benefits of ORV.  相似文献   

18.
By establishing a breeding programme for transmissible spongiform encephalopathie (TSE) resistance, there are plans to eradicate sheep TSEs from member states of the European Union (EU). In this paper, we used a simple age- and genotype-structured model to assess the impact of four breeding strategies on the prevalence and incidence of scrapie in the British sheep flock. The strategies ranged from the minimum EU requirements to compulsory implementation of the current National Scrapie Plan for Great Britain (NSP). All four strategies were predicted to reduce the prevalence and incidence of disease, though there was likely to be a delay of several years between the implementation of a breeding programme and the reduction in incidence. There were differences in the efficacy of the strategies, with the most stringent resulting in the greatest reduction in prevalence and incidence. However, the magnitude of the differences was not great, largely because all four strategies eliminated the VRQ allele, which is associated with a markedly higher risk of disease than any of the other alleles. Sensitivity analyses indicated that the model results were robust to selection bias when estimating the risk of infection; and that the efficacy of a breeding programme was unlikely to be compromised, unless the risk of infection is substantially underestimated by data on clinical disease.  相似文献   

19.
The effect of a continuous disinfection programme, using the non-toxic disinfectant Virukill, in layers, on the spread and impact of infectious coryza, caused by Haemophilus paragallinarum was evaluated. In this experiment, both unvaccinated layers and layers vaccinated against infectious coryza were used. Duplicate smaller groups of vaccinated and unvaccinated chickens were challenged with different serovars of both NAD-dependent as well as NAD-independent isolates of Haemophilus paragallinarum. One group of chickens challenged with each of the different becterial serovars was treated with the continuous disinfection programme, while the other group remained as the untreated controls. The clinical signs of infectious coryza were evaluated over a period of 20 days in each group. The egg production over this period was also evaluated. It was found in all experimental challenges, that the severity of the symptoms was reduced in the birds receiving the continuous disinfection programme. The drop in egg production was also found to be less severe in the treated groups when compared to the untreated control groups. The duration of infection was found to be either unchanged, or shorter in the birds treated with the continuous disinfection programme. In none of the experimental challenges was the duration or expression of clinical signs of IC increased due to the continuous disinfection programme.  相似文献   

20.
Ontario initiated a red fox (Vulpes vulpes ) oral rabies vaccination (ORV) programme in 1989. This study utilized a benefit‐cost analysis to determine if this ORV programme was economically worthwhile. Between 1979 and 1989, prior to ORV baiting, the average annual human post‐exposure treatments, positive red fox rabies diagnostic tests and indemnity payments for livestock lost to rabies were 2248, 1861 and $246 809, respectively. After baiting, from 1990 to 2000, a 35%, 66% and 41% decrease in post‐exposure treatments, animal rabies tests and indemnity payments was observed, respectively. These reductions were viewed as benefits of the ORV programme, whereas total costs were those associated with ORV baiting. Multiple techniques were used to estimate four different benefit streams and the total estimated benefits ranged from $35 486 316 to $98 413 217. The annual mean ORV programme cost was $6 447 720, with total programme costs of $77 372 637. The average benefit‐cost ratios over the analysis period were .49, 1.06, 1.27 and 1.36, indicating overall programme efficiency in three of the four conservative scenarios.  相似文献   

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