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1.
The study describes the profiles of culled cows in order to assess the possible contribution to economic losses due to health disorders. Data regarding dates of birth, final calving and culling, parity at culling, milk yield at the two first test-days of the final lactation and reason(s) for culling were collected in a 5-year survey, carried out from 1989 to 1994 in 84 commercial Holstein farms in western France. Polytomous logistic regression was used to assess the relationship between parity, calving-to-culling interval, milk yield and eight groups of primary culling reasons (i.e. udder disorders; infertility or reproductive disorders; lameness or foot/leg defects; emergency culling reasons; other health disorders; low milk yield; sales for dairy purpose; and other voluntary culling reasons). Out of a total of 5133 culled cows, the proportions of culls, for each of these groups of reasons, were 12.4, 28.4, 2.7, 3.9, 4.6, 16.7, 5.9, and 25.4%, respectively. Cows culled for udder disorders left the herd earlier in lactation and were more frequently at parities 4–6 than cows culled for voluntary reasons. In contrast, cows culled for infertility were younger and culled later within lactation. They were also higher yielding cows than those culled for other reasons. Cows culled for lameness were similar to those of the voluntarily culling group. Cows culled for emergency reasons were more frequently younger cows in early lactation. Cows culled for other health disorders left the herd early in lactation, but at a higher parity than the voluntarily culled cows. These results suggest that most of the culls related to health could be contributing to economic loss. However, special priority should be given to reduce culling for reproductive problems, which is the most costly exit reason. 相似文献
2.
The aims of this follow-up study were: (a) to evaluate the role of ECT technology as a risk factor for several diseases; and (b) to determine if the effects of these diseases on cows' reproductive performance and as risk factors for culling are influenced by exposure to ECTs. Diseases considered were retained placenta, metritis, ketosis, cystic ovaries, silent heat, milk fever, clinical mastitis, and foot and leg problems. We used historical and contemporary controls (with control herds selected to match the experimental herds for size and location). Data consisted of 10264 Swedish Red and White (SRB) and 5461 Swedish Friesian (SLB) lactation records in 150 herds of which 33 used cow-trainers. Logistic regression was used to estimate the effects of parity and exposure to electric cow-trainers on the risks of diseases and the effects of diseases and exposure to electric cow-trainers on risk of culling. The least-squares procedure was used to estimate the effects of diseases on reproductive performance.
The dominant effects associated with use of electric cow-trainers were an increased risk for silent heat, clinical mastitis, ketosis and culling relative to cows in herds not using cow-trainers. Diseases had negative effects on reproductive performance and the effects were larger for cows in herds using cow-trainers. In herds using electric cow-trainers, the largest increase in the interval from first service to conception (58 days) was caused by the occurrences of silent heat, cystic ovaries and the combination of two or more diseases. Retained placenta, metritis, cystic ovaries, clinical mastitis and a combination of two or more diseases increased the risk of culling about two times relative to healthy primiparous cows with the increase being greater for cows in herds using cow-trainers. Silent heat did not increase risk of culling in control groups, but was the largest risk factor for culling in the exposed group. We concluded that exposure to electric cow-trainers increased the incidence risk of silent heat, clinical mastitis, and ketosis and changed silent heat from a neutral disease with respect to culling to a major risk factor. Finally, exposure to cow-trainers increased the general negative effect of diseases on the cows' reproductive performance and risk for culling. 相似文献
3.
Social-ethical issues concerning the control strategy of animal diseases in the European Union: A survey 总被引：1，自引：0，他引：1
Nina E. Cohen Marcel A.P.M. van Asseldonk Elsbeth N. Stassen 《Agriculture and Human Values》2007,24(4):499-510
In 2004 a survey was conducted in the member states of the European Union designed to gain greater insight into the views
on control strategies for foot and mouth disease, classical swine fever, and avian influenza with respect to the epidemiological,
economic and social-ethical consequences of each of these animal diseases. This article presents the results of the social-ethical
survey. A selection of stakeholders from each member state was asked to prioritize issues for the prevention and control of
these diseases. A majority of stakeholders chose preventive measures as the preferred issue. An analysis was done to determine
whether there were differences in views expressed by stakeholders from member states with a history of recent epidemics and
ones without such a history, and whether there were regional differences. There were no differences between member states
with or without a history of recent epidemics. There were indeed regional differences between the priority orders from Northern
and Southern Europe on the one hand, and from Eastern Europe on the other.
Nina
E. Cohen
is a biologist and is a researcher at the Wageningen University. She is specialized in societal and ethical issues in human–animal
relationships. Her current research is focused on the social-ethical issues concerning the prevention and control of foot
and mouth disease, classical swine fever and avian influenza.
Marcel A.P.M. van Asseldonk
has studied animal science. Currently he works at the Institute for Risk Management in Agriculture (IRMA) of the Wageningen
University. He is specialized in the design and pricing of insurance policies and animal health funds for the main livestock
epidemics.
Elsbeth N. Stassen
is a veterinarian and professor of Animals and Society at the Wageningen University. Elsbeth Stassen is specialized in animal
health, animal welfare and human–animal relationships. She was a member of a governmental welfare committee during the avian
influenza epidemic in the Netherlands in 2003. 相似文献
4.
Conservation management options for southern African elephants range from local to regional scales. Here we review these options and argue in favour of actions that will deal with the causes rather than symptoms of elephant numbers that are locally high. Metapopulation theory ensures population persistence, while our approach extends this in order to stabilise elephant numbers regionally. By allowing for the development and maintenance of regional sinks, we may also limit numbers in sources. This application of the metapopulation metaphor is a powerful ecological platform from which to manage elephant numbers and impact through southern Africa. Our approach engages the causes of the apparently high abundance of elephants in parts of southern Africa. It moves away from the practice of dealing only with numbers (symptoms) when managing the impact of elephants on other species. While providing an ecological basis for the development of elephant management options, this needs to be melded with social, political and economic realities through southern Africa. In this regard we are encouraged by the ongoing development of several Transfrontier Conservation programmes and Peace Parks across the region. 相似文献
5.
Because of the risk to public health posed by the potential presence of bovine spongiform encephalopathy (BSE) in sheep, there are plans to eradicate transmissible spongiform encephalopathies (TSEs) from the British sheep population. We used a mathematical model for the spread of scrapie between sheep flocks to assess the efficacy of five control strategies at eradicating the infection from the national flock. These range from ram-genotyping schemes through whole-flock genotyping with selective culling to whole-flock slaughter. The impact of control was considered under three scenarios for the long-term dynamics of scrapie in GB: two in which scrapie is ultimately eliminated (with different median extinction times) and one in which scrapie remains endemic. Results suggested that it is feasible to eradicate scrapie from the British sheep flock, but that any national control programme will take decades to eliminate the disease and be costly. The most-effective strategy, measured in terms of the probability of eradication and time taken for eradication, was predicted to be whole-flock culling, which was effective under all three scenarios for the long-term dynamics of scrapie. Strategies involving whole-flock genotyping with selective culling were also effective, though they were predicted to take longer to eradicate scrapie than whole-flock culling. Ram-genotyping schemes were effective in some instances, but not for the scenario where scrapie remained endemic in the national flock. At low levels of reporting of clinical disease (<20%) the probability of eradication within 100 years was predicted to be <100% and, consequently, low levels of reporting could compromise the effectiveness of a control programme. Moreover, the predicted time taken to eradicate scrapie would increase markedly if the reporting compliance decreased. 相似文献
6.
First-fortnight incidence (FFI) is a modelling parameter that can be used to predict both the prevalence and duration of a foot-and-mouth disease (FMD) epidemic at regional and national levels. With an indication of how long an epidemic may last by the end of week two, it becomes possible to estimate whether vaccination would be economically viable from the start of an epidemic. Where FFI indicates that an epidemic is unlikely to last for as long as an export ban on agricultural produce, it may be inappropriate to implement a policy of 'vaccination to live'. Alternatively where FFI indicates that an epidemic will equal or exceed the ban length, then the benefits of vaccination should be considered at an early stage, during or after the first fortnight. Since blanket vaccination of the national or regional herds and flocks would be both costly and heighten the risk of producing carrier animals, targetting vaccination through risk assessment becomes useful. 相似文献
7.
A functional herd dynamics model was developed to estimate the effect of culling age on milk and meat production for Japanese-Saanen goats in relation to changes in prices of milk and meat. The model simulates life cycle production of bucks and does and their kids. Every production trait is first modelled as an individual trait and thereafter as a trait in the herd using a herd dynamics model. At the individual level, the survival curve function, the litter size function and the production traits function are combined. Data on growth and lactation were used to fit growth and lactation curves to estimated parameters using non-linear least squares regression technique and used in the production traits function. Using herd dynamics, the individual level functions are combined with the total number of animals function to estimate the total herd output and income efficiency at the herd level. Here, variables of culling days including the effect of difference in meat price value among goat categories (bucks, does, male kids and female kids) are used. Analysis of interrelations among the culling days of does, the price ratio and the income efficiency indicated that optimal culling days of does was shortened with an increase in the price ratio of meat to milk. However, when meat price value was different among goat categories according to actual situation of Japanese goat production, the optimal culling days of does could be fixed regardless of the change in price ratio and was calculated as 1730 days. This functional herd dynamics model can aid in decision-making regarding culling under several situations especially when there is a wide fluctuation in prices at local markets. 相似文献
8.
禽流感扑杀补偿政策的市价补偿标准问题探析 总被引：2，自引：0，他引：2
扑杀是政府应对禽流感疫情的有效应急措施,对扑杀的禽只给以补偿是对禽主因扑杀而遭受损失的必要补救.补偿标准的高低直接影响着禽主配合政府扑杀行动的意愿和积极性.在剖析现行补偿标准缺陷的基础上,分析了市价补偿标准的必要性和可行性,并提出了相应的对策和建议. 相似文献
9.
Alastair I. Ward Piran C.L. White Neil J. Walker Charles H. Critchley 《Forest Ecology and Management》2008,256(6):1333-1338
At moderate to high densities ungulates can impact negatively on forest crops and these may be managed by lethal control. In production forestry an understanding of the relationship between ungulate density, habitat-related factors and the incidence of tree damage may promote more efficient ungulate damage management than by lethal control alone. In plantation forests in the north east of England, the incidence of conifer leader browsing by roe deer (Capreolus capreolus) was positively associated with an index of deer density (at the site scale) and planted crop tree density (at the feeding patch scale) and was negatively associated with the relative abundance of palatable understorey vegetation (at the site scale). An interaction between the deer density index and palatable understorey browse abundance was positively associated with leader browsing. Coefficients from the optimal model were used to construct a browse probability surface across a matrix of values of deer dung density and palatable understorey vegetation abundance. This illustrated a very different relationship between dung density and conifer leader browsing probability across the various levels of palatable understorey vegetation abundance. From this we hypothesise that in areas of limited palatable understorey vegetation abundance, higher levels of culling may be required to achieve reductions in the incidence of conifer leader browsing than would be necessary in areas with moderate to high palatable understorey vegetation abundance. Improvements to understorey vegetation in concert with roe deer population control may enhance the efficiency of deer damage management in upland areas with nutrient-poor soils. 相似文献
10.
The analysis of binary data originating from clustered observations is often a problem in epidemiological studies. In most epidemiological studies on cattle, clustering occurs at two levels: cows are clustered within herds and lactation records are clustered within cows. This paper proposes and assesses a method of eliminating one level of clustering in regression analysis.
Data from an observational study were used to assess the relationships between health disorders and culling, by means of logistic regression analysis, in two different ways. In the Random One Lactation (ROL) analysis, ten random selections of one lactation record per cow were done. Logistic regression analysis was performed in each sample separately. Results showed qualitative and quantitative variations between the ten final models. From the ten random samples, a disease was considered as significantly associated with culling, if present in at least four final models. Using a single random sample might give incomplete information. In the All Lactations (AL) analysis, all the available lactation records were included in one model, despite the dependency between lactations.
The two methods generally agreed. All diseases significantly related in the AL analysis, except one, were also significantly associated with culling with the ROL analysis. However, differences in the regression coefficients between the ROL and the AL analyses showed the importance of dispersion parameters. 相似文献