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Animal diseases are global issues affecting the productivity and financial profitability of affected farms. Johne’s disease is distributed on farms worldwide and is an endemic contagious bacterial infection in ruminants caused by Mycobacterium avium subspecies paratuberculosis. In cattle, the clinical disease manifests itself as chronic enteritis resulting in reduced production, weight loss, and eventually death. Johne’s disease is prevalent in the UK, including Scotland. Direct costs and losses associated with Johne’s disease have been estimated in previous research, confirming an important economic impact of the disease in UK herds. Despite this, the distributional impact of Johne’s disease among milk consumers and producers in Scotland has not been estimated. In this paper, we evaluate the change in society’s economic welfare, namely to dairy producers (i.e. infected and uninfected herds) and milk consumers in Scotland induced by the introduction of Johne’s disease in the national Scottish dairy herd. At the national-level, we conclude that the economic burden falls mainly on producers of infected herds and, to a lesser extent, milk consumers, while producers of uninfected herds benefit from the presence of Johne’s. An infected producer’s loss per cow is approximately two times larger in magnitude than that of an uninfected producer’s gain. Such economic welfare estimates are an important comparison of the relative costs of national herd prevalence and the wider economic welfare implications for both producers and consumers. This is particularly important from a policy, public good, cost sharing, and human health perspective. The economic welfare framework presented in this paper can be applied to other diseases to examine the relative burden of society’s economic welfare of alternative livestock disease scenarios. In addition, the sensitivity analysis evaluates uncertainty in economic welfare given limited data and uncertainty in the national herd prevalence, and other input parameters, associated with Johne’s disease in Scotland. Therefore, until the prevalence of Johne’s is better understood, the full economic cost to Scottish dairy herds remains uncertain but in the meantime the sensitivity analysis evaluates the robustness of economic welfare to such uncertainties.

The paper uses structural equation modelling applied to survey data to test determinants’ influence on UK cattle farmers’ intentions towards Escherichia coli O157 control. Results suggest that farmers more likely to be willing to control Escherichia coli O157 are those who think that farmers are most responsible for controlling disease; whose income depends more on opening farms to public; with stronger disease control attitudes; who were affected by outbreaks; with better knowledge and more frequent information access; with stronger perceptions towards practicality of biosecurity measures; who use health plans; who think farmers are main beneficiaries of controlling disease; whose farm is dairy rather than beef.

Sclerotinia rot is a disease caused by the fungus Sclerotinina sclerotiorum which affects a wide range of crops and causes major yield and economic losses. Crop rotation is an important strategy for minimising losses. A dynamic programming (DP) model was developed to study the trade-offs between state of the land, severity of sclerotinia and financial impacts as a result of different cropping decisions. Results showed that rotation and treatment against sclerotinia was financially justified yet permitted intensive yet sustainable production of susceptible food crops in the long-run. Allocation of even a small proportion of cropping decisions to break crops coupled with treatments in the rotation mitigated long-term build-up of sclerotia in land. However in the short-run, high proportions and high frequencies of cropping decisions need to be either allocated to break crops or treated-susceptible crops in order to avoid the disease and to generate profit. Results showed that DP methodology provides a useful framework to explore the trade-offs between crop rotation and growing high value susceptible crops in the long- and short-term in relation to plant diseases in arable agriculture that are at the heart of sustainable food production and land use.

A bio-economic linear program based on data from 20 commercial extensive sheep farms was used to predict the effects on aspects of farm management of response to CAP reform in Great Britain. The objective function of the LP was to maximise gross margin while meeting ewe energy requirements from farm grown or purchased feeds on a monthly basis throughout the farming year. Three farms were constrained by availability of home-grown grass and thus contracted under a subsidy free scenario. Just one farm justified expansion using extra labour purchased at £5/hour. The other farms remained at current flock sizes using existing unpaid labour. However, all farms adjusted their grazing regime according to the balance of land types available. These adjustments varied from month to month, reflecting the complex and dynamic pattern of interactions between resource demand and supply throughout the farming year. The implied shifts in land use have implications for the environment and for animal welfare.

This study quantified interactions between animal welfare and farm profitability in British extensive sheep farming systems. Qualitative welfare assessment methodology was used to assess welfare from the animal's perspective in 20 commercial extensive sheep farms and to estimate labour demand for welfare, based on the assessed welfare scores using data collected from farm inventories. The estimated labour demand was then used as a coefficient in a linear program based model to establish the gross margin maximising farm management strategy for given farm situations, subject to constraints that reflected current resource limitations including labour supply. Regression analysis showed a significant relationship between the qualitative welfare assessment scores and labour supply on the inventoried farms but there was no significant relationship between current gross margin and assessed welfare scores. However, to meet the labour demand of the best welfare score, a reduction in flock size and in the average maximum farm gross margin was often required. These findings supported the hypothesis that trade-offs between animal welfare and farm profitability are necessary in providing maximum animal welfare via on-farm labour and sustainable British extensive sheep farming systems.

Sheep welfare is an emerging topic in research and food marketing, and recent studies suggest that farm labour is a key factor for both animal welfare and productivity in extensive sheep farming systems, although little research has been done into labour utilisation in these systems. This paper reports field data collection on two commercial farms and the use of a linear programming (LP) model to link labour economics and animal welfare analysis. The model maximises the number of ewes to clooked after over the lambing period, when constrained by labour availability for various key tasks and by a pre-determined level of sheep welfare. The results show a trade-off between welfare level and labour input per sheep. Dropping tasks with less significant welfare and productivity consequences is an effective way of increasing carrying capacity (from 977 ewes/shepherd to 1428), as is working longer hours (1174 ewes/shepherd) or only doing the legal minimum of welfare checking (labour reduced from 0.68 min/ewe to 0.44 min/ewe) . The field data suggest that farmers currently provide high welfare, and that, despite much time spent away from the flock (e.g. driving), they spend a large amount of time (39% of total) with their sheep.

A methodology is described to establish the relative financial benefit of farm animal disease prevention (biosecurity). This methodology is demonstrated using the example of bovine viral diarrhoea virus (BVDV) incursion on beef suckler farms in Scotland. A random sample of 276 herds was taken and a proportion of young stock on each farm tested for previous exposure to BVDV. There was evidence that 0.4 of herds had been exposed over one year prior to sampling. All herds completed a questionnaire about their biosecurity practices. The influence of these practices on relative risk of BVDV was subjected to a Chi squared test and practices ranked accordingly. Most important risk factors were animal buying in strategy, farm size and a single farm boundary. The economic benefit/disbenefit of these strategies was assessed using a bio-economic model of a 10-year BVDV epidemic. Expected output losses due to BVDV infection and risk were affected by biosecurity strategy and by level of biosecurity threat. The implications of these findings for animal health strategy at farm and regional level are discussed.

This paper provides an ex-ante economic analysis, comparing six alternative control strategies for the eradication of Bluetongue virus 8 against five incursion scenarios in cattle and sheep populations. The economic analysis assumes a common baseline unavoidable cost of public and private measures that together contribute to prevention of incursion of BTV8 into Scotland. These costs continue over the five year horizon of this analysis regardless of whether a BTV8 epidemic ensues in Scotland and their total present value was found to be approximately £141m over the 5year period. The benefit of this investment is the costs of a BTV8 outbreak avoided; which depends on the time, location and nature of the incursion, on the control strategies adopted to counter each incursion, on the persistence of the incursion and on the opportunities to mitigate the damage. Specific variations in all these aspects were explored. The benefit-cost ratios were ranked within each incursion scenario to evaluate the efficiency of control outlays. Although the economic model found that benefit-cost ratios were greater than 1 for all interventions strategies examined, the control strategy option with 100% vaccination and protection zone set at Scottish Borders were economically preferable. This implies that if avoided this control option would deliver the greatest benefit from investment in baseline prevention costs. However, in terms of outbreak losses, this vaccination strategy was always most costly. On the other hand, the control strategy with 50% vaccination and all Scotland as a protection zone often provides the lowest benefits in all control options examined

An epidemiological model is described that closely mimicked results of a published serological study of natural transmission of Maedi-Visna virus in a low ground flock of sheep. We adjusted parameters in the model from this baseline to explore the possible implications for the control of Maedi-Visna virus in typical British flocks. On closed hill farms, low probability of effective contact was most critical for control. In open low ground flocks, purchasing accredited replacements eliminated disease spread, otherwise flock size was the most important factor governing flock prevalence. Results highlighted the need for more epidemiological information about Maedi-Visna, particularly whether hill farms act as a hidden reservoir of virus or reduce the impact of this disease on the industry by providing a source of clean replacements

Data from each of 5 commercial, extensive sheep farms in Cumbria, UK were used as parameters in a linear program (LP) representing labour and grazing management in such farming systems. The LP maximised ewe enterprise gross margin subject to constraints dictated by the labour availability and land types on each farm. Under the assumptions used, labour availability and price restricted ewe numbers well below those observed in practice on 2 farms i.e. land resources were adequate for the farming system practiced. On two other farms stocking levels and hence returns were limited by the availability of forage and hence feed input prices relative to output. On one farm, greater grassland productivity was the key determinant of system performance. It was concluded that a holistic systems approach was needed to properly evaluate these farming systems in terms of their potential contribution to animal welfare, land use, profit and hence their sustainability

Results of national and pan-European consumer surveys and the growth in the demand for so-called “animal friendly” food products suggest that consumers within the European Union show a high level of concern for the welfare of farm animals. This paper analyses the determinants of British consumers’ behaviour towards animal welfare using structural equation models (SEM) with observed and latent variables. SEM is a statistical technique for testing and estimating relationships amongst variables, using a combination of statistical data and qualitative causal assumptions. We used a data set collected in 2005 through face-to-face interviews of 654 consumers in England. We analysed the range of statements in existing literature on consumers’ behaviour towards animal welfare and then used SEM to test and estimate these a priori determinants of behaviour. The models include observed and latent variables representing behaviour (stated purchases of free-range and organic chicken meat) and its underlying determinants (attitudes towards animal welfare and socio-economic factors). The models have an adequate overall fit to the data. The significance tests for the structural equation model on free-range chicken meat purchasing behaviour show socioeconomic group, education, attitudes towards animal welfare, reasons for buying chicken meat, access to information on animal welfare issues, number of children and price as significant determinants. All of these (with the exception of reasons for buying chicken meat) were found significant also in the model on organic chicken meat purchasing behaviour.

Since decoupling of the CAP, many Scottish suckler cow farms are facing financial difficulties. In response, many farmers are out-wintering extensively managed suckler cows to minimise production costs. These systems are of animal welfare concern. A range of trade-offs between animal welfare indicators and between animal welfare and farm profitability can be identified. A Dynamic Programming (DP) model was developed to study these trade-offs. Two herds were modelled assuming their feeding regimes were either low (LHERD) or high (HHERD). The objective of the DP was to maximise the expected net margin from a current cow and its successors over an infinite time horizon. Preliminary results showed that the rate of voluntary culling was higher in HHERD than in LHERD. Animals in HHERD had shorter life expectancy. The expected net present value was 58% lower in LHERD than HHERD (-£41.5 and - £24.3 respectively). These results suggest a heavier culling rate and shorter longevity for animals in HHERD that compromises animal welfare. Also HHERD had a greater implied stocking density than LHERD. This increase of the cows’ population may adversely affect the environment. The presented model provides some of the basic information required to explore some of the trade-offs between farm profit, animal welfare and the environment.

This research analyses the impacts of a scientific advance that improves animal welfare, upon the environment and trade in Scotland using partial equilibrium (PE) modelling. The science improves pig neonatal survival through improved (high fibre) sow diets used before mating. Our model simulates the effects of animal welfare changes on the pig production systems (pig meat) and further on trade flows (trade in pig meat) and environment (water and air pollution). We consider two animal welfare simulation scenarios, namely the status quo – no animal welfare change as regards pig neonatal mortality (baseline scenario) and the case of improving pig neonatal survival (alternative scenario) and compare the impacts on trade and environment between the two scenarios during the simulation horizon 2008-2015. The results show that the increase in animal welfare has a lower impact on the environment in the alternative scenario compared to the baseline scenario (by about 6% at the end of the simulation horizon) and a positive impact on net trade in the alternative scenario compared to the baseline scenario (by about 13% at the end of the simulation horizon).

In this paper, we evaluated the welfare effects of a hypothetical programme of Johne's disease eradication from the Scottish dairy herd on different stakeholders in the domestic milk market. We undertook the evaluation using a Markov-Chain simulation and applying an economic welfare analysis which takes into consideration the effects of an eradication programme on product price, on output quantity, on cost and on milk yield for given levels of supply and demand elasticities. We found that, following the eradication of the disease, milk yield per cow increased for all herd sizes in Scotland whereas price and unit cost of milk production fell. Consequently, milk consumers gained around £14.3 million in discounted economic surplus and producers with infected herds around £13.4 million whereas producers with uninfected herds lost around £10.7 million in discounted surplus. The gain in surplus made by consumers and owners of infected herds, however, more than made up for the loss in surplus made by owners of un-infected herds. Therefore, on balance, Scotland gained a net economic surplus of £17 million from the programme.

A survey of the management of reproduction on 66 Scottish suckler herds calving in spring 2003 was analysed using multiple regression. The predicted mean value of suckled calves produced was £237/cow (SE 1.8). The regression coefficients of the predictors was 0.74 (0.05), 15 (3.9) and 248 (16.5) for date of first calving, average number of 21-day calving periods (calving spread) and proportion of cows barren respectively. Improving each predictor by 1 SD had the combined potential to improve predicted calf value by £64/cow, over 80% of the current typical gross margin for this type of enterprise. Bull care had a significant influence on calving spread and number of biosecurity measures taken had a positive influence on the proportion of cows barren. However, length of breeding season had no significant impact on the above predictors. Reproductive performance was highly variable and indicators were considerably poorer than published targets. It was concluded that farmers in this sample were not managing their herds for high reproductive performance and output as often advocated. This result suggests considerable scope for improved private and public benefits from the management of reproduction in this type of beef production system.

The paper analyses the problem of information in the cattle market, particularly as it relates to the status of animal health, and discusses ways to limit it with the view to improving social surplus. Against this background, it aims to achieve three major objectives. Firstly, it describes the ways of improving the level of information through such schemes as Conventional Warranties and Third Party Certification and the different choices made by sellers and buyers in the presence of these schemes. Secondly, it studies the various ways by which these schemes make an impact on equilibria in different markets (i.e., the pooling market and the premium market), and, consequently, on the social surplus. Thirdly, it identifies the necessary conditions for a third party/public decision-maker to increase social surplus and reduce the negative externality caused by disease by managing and supporting Third Party Certification. The paper shows that product certification and product warranty cannot coexist because product warranty is suboptimal. It also shows that certification, and a possible supporting of certification or animal testing does not necessarily improve the safety of the trade.

Endemic disease of animals is an economic problem as it deprives humans of scarce resources that might otherwise satisfy human wants. Optimisation methods identify the strategies that minimise this economic problem. Given the potentially vast extent of the deprivation, not only in terms of lost wealth but also in terms of animal welfare, human health and environmental damage, this subject offers great benefits to decision-makers from the individual farm to the global level. This paper uses examples to illustrate the basic economic principles concerned. It shows how these principles may be extended to deal with current limitations in theory and practice. Lack of data is a common problem that may be dealt with by using computer simulation, theoretical approaches or the experiential knowledge of the decision-makers themselves. The latter method has the added advantage of greatly assisting with the difficult problem of effectively communicating the results of decision analysis to the decision-maker. In most situations the decision-maker will need to strike a balance between conflicting objectives such as short term profit and long term environmental damage (sustainability). This problem will require a wider perspective, which is greatly facilitated by collaboration between economists and scientists. The paper illustrates ways in which this has been done by using decision analysis methods to focus on the decision rather than the disease. The conclusions highlight priority areas for future research and development in this area. Topics include the contribution of endemic disease control to sustainable development, endemic disease eradication, capturing wider implications such as animal welfare and food safety, accounting for variation in rational decision making and dealing with risk.

Since decoupling of the CAP, many Scottish suckler cow farms are facing financial difficulties. In response, many farmers are out-wintering extensively managed suckler cows to minimise production costs. These systems are of animal welfare concern. A range of trade-offs between animal welfare indicators and between animal welfare and farm profitability can be identified. A Dynamic Programming (DP) model was developed to study these trade-offs. Two herds were modelled assuming their feeding regimes were either low (LHERD) or high (HHERD). The objective of the DP was to maximise the expected net margin from a current cow and its successors over an infinite time horizon. Preliminary results showed that the rate of voluntary culling was higher in HHERD than in LHERD. Animals in HHERD had shorter life expectancy. The expected net present value was 58% lower in LHERD than HHERD (-£41.5 and - £24.3 respectively). These results suggest a heavier culling rate and shorter longevity for animals in HHERD that compromises animal welfare. Also HHERD had a greater implied stocking density than LHERD. This increase of the cows’ population may adversely affect the environment. The presented model provides some of the basic information required to explore some of the trade-offs between farm profit, animal welfare and the environment.