Slaughter Strategies Research Articles

Seroprevalence of brucellosis in dairy animals and their owners in selected sites, central highlands of Ethiopia

ABSTRACT A cross-sectional study was conducted from December 2019 to May 2020 to determine the seroprevalence and identify potential risk factors of brucellosis in dairy cows and owners. Purposive sampling was performed in the respective farms and kebeles to screen recent cases of abortion. The overall seroprevalence of bovine and human brucellosis was 0.61% (95%CI:0.016–2.09) and 1.21% (95%CI:0.032–4.27) respectively using combined RBPT and CFT tests. Late stage of abortion (OR = 14.74, p = 0.0002), retained fetal membrane (OR = 32.74, p = 0.006), market-based stock replacement (OR = 16.55, p = 0.002), and presence of parturition pen (OR = 11.511, p = 0.027) was found to be significantly associated with seropositivity for Brucella infection in dairy cattle. Human housing (OR = 1.8, p = 0.002), contact with aborted fetus (OR = 21.19, p = 0.017), and drinking raw milk from aborted (OR = 5.72, 0.019) and retained fetal membrane (OR = 4.22, p = 0.029) cows all had a significant influence on human brucellosis seropositivity. A structured interview question was administered to 284 respondents. Accordingly, most respondents had no knowledge of bovine brucellosis and their zoonotic effects (93.3%) in contrast most of them drink raw milk. Implementation of a test and slaughter strategy with compensation is recommended with this low prevalence. In the case of human brucellosis, implementing one health approach framework should be practiced.

Seroprevalence of Brucellosis in dairy animals and their owners in selected sites, Central Highlands of Ethiopia

A cross-sectional study was conducted from December, 2019 to May, 2020 with the aim of determining seroprevalence and identifying the potential risk factors of brucellosis in dairy cows with recent cases of abortion and their owners and farm workers in selected sites in the central highland of Oromia, Ethiopia. The overall seroprevalence of bovine and human brucellosis was 0.61% (95%CI: 0.016–2.09) and 1.21% (95%CI: 0.032–4.27) using combined RBPT and CFT tests, respectively. The late stage of abortion (OR = 14.74, p =0.0002), retained fetal membrane (OR = 32.74, p=0.006), market-based stock replacement (OR = 16.55, p=0.002), and presence of parturition pen (OR = 11.511, p=0.027) were found to be significantly associated with seropositivity for Brucella infection in dairy cattle. Human housing (OR = 1.8, p = 0.002), contact with aborted fetus (OR = 21.19, p = 0.017), and drinking raw milk from aborted (OR = 5.72, 0.019) and retained fetal membrane (OR = 4.22, p= 0.029) cows all had a significant influence on human brucellosis seropositivity. A structured interview question was administered to 284 respondents. Accordingly, most respondents had no knowledge of bovine brucellosis and their zoonotic effects (93.3%) in contrast most of them drink raw milk. Implementation of a test and slaughter strategy with compensation is recommended with this low prevalence. In the case of human brucellosis, implementing one health approach framework should be practiced.

Preslaughter stress and beef quality in relation to slaughter transport of cattle

Preslaughter handling inevitably exposes cattle to stress, which affects beef quality and yields. Short transports to the slaughterhouse or a short walk across the yard to a mobile abattoir parked on the farm may reduce stress, with potential beneficial effects on meat quality. To compare different road transport distances to a stationary (fixed) slaughterhouse, and the stationary plant with a mobile abattoir, we studied commercial slaughter of 298 cattle in each facility over a period of 13 months. For the stationary slaughterhouse, the estimated transport distance from farm to plant was 7–250 km (mean 99 km) and 96 animals spent one night in lairage there. All animals at both slaughterhouses were stunned with a captive bolt gun. Blood levels of cortisol, glucose and lactate at exsanguination and meat quality indicators were recorded. According to two-sample t-tests, thawing loss was 1 percent unit lower (p<0.0001), Warner-Bratzler shear force was 6.9 N lower (p<0.0001) and compressive load was 3.9 MPa lower (p<0.0001), but mean lactate level was 1.02 mmol/l higher (p<0.0001) and ultimate pH was 0.05 units higher (p=0.0001) in the mobile facility compared with the stationary. Effects of slaughter facility and estimated road transport distance to the stationary plant on blood lactate, ultimate meat pH, shear force and compressive load were analysed by generalized linear mixed models, with delivering farm as random effect. According to the models, predicted shear force was 23% higher at the 95th percentile of the transport distance compared with the 5th percentile (p=0.012), and there was some evidence of a similar difference in compressive load for heifers, albeit only marginally significant (39% higher at the 95th percentile; p=0.056). Predicted blood lactate was 19% higher in the mobile abattoir than the stationary slaughterhouse (p=0.046). Ultimate meat pH was higher in the mobile unit for cows and steers (p≤0.0020), and for carcasses weighing 311–380 kg (p≤0.0020). Compressive load was 27% lower in the mobile abattoir, compared to the stationary (p<0.0001), but shear force did not differ significantly between the two facilities. This study shows a negative effect of long transport distances on beef tenderness. It also provides evidence of differences in beef quality between a mobile abattoir and a stationary slaughterhouse, although these differences may be attributable to specific routines for carcass handling and ageing at the studied facilities, and not the transport and slaughter strategy itself.

Investigation of an outbreak of brucellosis in a mixed dairy farm and evaluation of a test and slaughter strategy to release the herd out of the quarantine

An outbreak of brucellosis in a mixed dairy farm with 508 animals (370 cows, 120 sheep, and 18 camels) at Fayoum governorate, North Upper Egypt, was investigated. A storm of abortion and several cases of retained placenta were reported among cows and ewes in April 2020. Serodiagnosis of brucellosis was done using Rose Bengal Test (RBT) and Buffered Acidified Plate Antigen Test (BAPAT). The Milk Ring Test (MRT) was applied to the milk of seropositive animals. A total of 89 samples were used for isolation of Brucella and isolates were confirmed using Abortus, Melitensis, Ovis, Suis-PCR (AMOS-PCR). Test and slaughter strategy was applied to eradicate brucellosis from the farm based on RBT every month until three successive negative tests were obtained. Results showed that the seroprevalences of brucellosis based on RBT and BAPAT were 9.5%, 35%, and 50% in cattle, sheep, and camels, respectively. Despite 50% of male camels being seropositive, no clinical signs have been reported. The MRT identified fewer positive cases than BAPAT and RBT, thus, it cannot be used alone to eliminate the infection from the farm. A total of 31 Brucella isolates were recovered from cows and sheep on the farm. All isolates were confirmed as Brucella melitensis bv3 based on bacteriological examination and Brucella AMOS-PCR confirmed all isolates as Brucella melitensis. No positive reactors at the 6th, 7th, 8th, 9th, and 10th examinations were reported after the implementation of the test and slaughter strategy. In conclusion, extensive animal farming and mixed breeding are potential risk factors for interspecies transmission of brucellosis. Additionally, the test and slaughter strategy could be helpful to release the herd out of quarantine, however, application of biosecurity practices and fair compensation policy for owners should be implemented.

Some aspects of effective control of Bovine infectious rhinotracheitis in European countries

Data on the epizootic situation concerning bovine infectious rhinotracheitis in the countries of the European continent are presented. Most of the countries that are members of the World Organization for Animal Health have implemented anti-epidemic measures on their territory, which include observation, reporting, monitoring or screening, as well as control of the movement of animals within the country and precautionary measures at the border. It has been noted that permanent safety in relation to the disease is possible only under the conditions of implementation of mandatory control measures at the state level, which are based on the removal of seropositive animals infected with an epizootic strain of the virus from herds simultaneously with or without the use of vaccines. In most countries of the European Union, IRT virus eradication programs have been implemented, which are based on research and removal strategies, as well as differentiation of vaccinated from infected animals. As the experience of the Scandinavian countries has shown, the most effective scheme is the eradication of the IRT pathogen by slaughtering infected animals, but this is only possible under conditions of a low level of livestock infection. The most economically feasible strategy for controlling IRT in herds with high levels of infection is the use of marker vaccines, followed by differentiation of vaccinated animals from infected ones and removal of the latter from the herd. When a low level of herd seropositivity is reached, it is advisable to implement a detection and slaughter strategy

Brucellosis in Iranian buffalo: prevalence and diagnostic methods

The water buffalo (Bubalus bubalis) in Iran represent an important source of meat and milk products with high biological value. Given the importance of water buffalo in Iran and the prevalence of brucellosis as one of the most important zoonotic diseases in this ruminant species, this study summarized available data on history, epidemiology, diagnosis, and control of brucellosis in water buffalo from previous studies that have been carried out in Iran. According to the documented data, there are three main groups of Iranian buffalo, including the Khuzestan ecotype (Khuzestan province); the Azary ecotype (Western/ Eastern Azarbaijan and Ardabil provinces); and the North ecotype (Gylan and Mazandaran provinces). Preliminary studies conducted on Iranian buffaloes either by serological or molecular tools reported that buffaloes' infection occurred due to natural exposure to a wild strain of Brucella abortus and Brucella melitensis. Previous studies dealing with brucellosis in Iranian buffalo are next to none. This review notifies the importance of reliable and detailed epidemiological investigations of Iranian buffaloes through continuous monitoring systems of the health status of buffalo populations. Continuous test and slaughter strategy, vaccination, and re-planning of veterinary activities are required to mitigate buffalo's role in disseminating and maintaining brucellosis in Iran.

Cloning and Expression of virulent proteins CFP-10 and ESAT-6 of Mycobacterium bovis AN5 for diagnosis of bovine tuberculosis

Aims and objects: Bovine tuberculosis caused by Mycobacterium bovis is an important disease that has negative effects in public health and economic losses. Traditional controlling program in cattle is based on test and slaughter strategy, but false positive is disadvantage of tuberculin skin test. To overcome the limitation, there is a need of using proteins with high specificity. The objective of this study was to clone and express of virulent protein CFP-10 and ESAT-6 of Mycobacterium bovis AN5 for diagnosis of bovine tuberculosis. Methods: Briefly, full-length genes of cfp-10 and esat-6 were amplified by PCR technique. In parallel pET23a (+) and PCR product has been double digested by EcoRI and HindIII. After Ligation, transformation was done into competent E.coli DH5α. Then the cloned vector was transformed into E.coli BL21. Induction was performed by isopropyl-β-D-thiogalactopyranoside (IPTG). The expressed proteins almost entirely in the inclusion body form. To dissolution of expressed protein, urea 8M was used. Purification of recombinant proteins was done by Nickle-Resin. Urea eliminated by decreasing gradient. Delayed hyper sensitivity of two proteins beside bovine tuberculin, avian tuberculin and human tuberculin studied in guinea-pig model. Results: Protein expression was confirmed by Western Blotting (WB) using 6X His-tag antibodies. The results showed that CFP-10 and ESAT-6 molecules has been successfully cloned and expressed in prokaryotic system. Results showed that CFP-10 has satisfactory relative potency but it is not in range about ESAT-6. Conclusion: The recombinant CFP-10 can play a significant role in reducing the false positive in diagnosis of bovine tuberculosis by improving the specificity of the tuberculin skin test

Effects of isolation and slaughter strategies in different species on emerging zoonoses.

Zoonosis is the kind of infectious disease transmitting among different species by zoonotic pathogens. Different species play different roles in zoonoses. In this paper, we established a basic model to describe the zoonotic pathogen transmission from wildlife, to domestic animals, to humans. Then we put three strategies into the basic model to control the emerging zoonoses. Three strategies are corresponding to control measures of isolation, slaughter or similar in wildlife, domestic animals and humans respectively. We analyzed the effects of these three strategies on control reproductive numbers and equilibriums and we took avian influenza epidemic in China as an example to show the impacts of the strategies on emerging zoonoses in different areas at beginning.

Systematic review of management strategies to control chronic wasting disease in wild deer populations in North America.

BackgroundChronic wasting disease (CWD) is a contagious, fatal prion disease affecting cervids in a growing number of regions across North America. Projected deer population declines and concern about potential spread of CWD to other species warrant strategies to manage this disease. Control efforts to date have been largely unsuccessful, resulting in continuing spread and increasing prevalence. This systematic review summarizes peer-reviewed published reports describing field-applicable CWD control strategies in wild deer populations in North America using systematic review methods. Ten databases were searched for peer-reviewed literature. Following deduplication, relevance screening, full-text appraisal, subject matter expert review and qualitative data extraction, nine references were included describing four distinct management strategies.ResultsSix of the nine studies used predictive modeling to evaluate control strategies. All six demonstrated one or more interventions to be effective but results were dependant on parameters and assumptions used in the model. Three found preferential removal of CWD infected deer to be effective in reducing CWD prevalence; one model evaluated a test and slaughter strategy, the other selective removal of infected deer by predators and the third evaluated increased harvest of the sex with highest prevalence (males). Three models evaluated non-selective harvest of deer. There were only three reports that examined primary data collected as part of observational studies. Two of these studies supported the effectiveness of intensive non-selective culling; the third study did not find a difference between areas that were subjected to culling and those that were not. Seven of the nine studies were conducted in the United States.ConclusionsThis review highlights the paucity of evaluated, field-applicable control strategies for CWD in wild deer populations. Knowledge gaps in the complex epidemiology of CWD and the intricacies inherent to prion diseases currently pose significant challenges to effective control of this disease in wild deer in North America.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0804-7) contains supplementary material, which is available to authorized users.

Market Economy vs. Risk Management: How Do Nomadic Pastoralists Respond to Increasing Meat Prices?

A growing body of evidence shows that for nomadic pastoralists herd accumulation is an efficient strategy for buffering environmental variation and maximizes long-term survival. Pastoralists may thus view livestock as investments, or ‘banks on the hoof,’ that work as insurance against unpredictable environmental conditions. This perspective differs from strict market logic where producers are expected to follow the ‘law of supply,’ i.e., that when the price of a product rises suppliers should be willing to offer more of the product for sale. In terms of insurance, increased meat prices may make it possible for pastoralists to slaughter fewer animals for the same financial gain as when prices are low and subsequently convert unslaughtered animals to herd capital. This study investigates to what degree Saami reindeer herders follow a market driven or risk management logic by investigating how slaughter strategies are influenced by increasing meat prices. While slaughter strategies vary regionally in Norway, our results indicate that reindeer herders follow neither risk nor market considerations alone, but rather a combination, and support the general hypothesis that slaughter strategies entail balancing the benefits of increasing herd size against economic gain through meat sales. This has important management implications since current management schemes aiming to reduce the number of reindeer by stimulating slaughter rates through economic subsidies is based on the assumption that herders are meat producers motivated by monetary gains alone.

Effect of on farm mixing and slaughter strategy on behaviour, welfare and productivity in Duroc finished entire male pigs

Animal welfare may be hampered due to a higher incidence of aggressive and sexual behaviours in entire males compared to castrated pigs. The aim of this study was to investigate the effect of mixing strategies on behaviour and physiological indicators of welfare and performance. Ninety-six entire male pigs were reared following either a wean to finish strategy in which no mixing was allowed after 14 days of age (WF, 48 pigs) or following a conventional strategy in which piglets were randomly mixed when entered to the transition and fattening pens at 72 days of age (MP, 48 pigs). Pigs were allocated in groups of 12 in 8 pens (4 WF pens and 4 MP pens). Two pens per housing system were slaughtered by split marketing (SM) in three days and the other two pens were slaughtered penwise (PW) when individual or pen mean body weight was around 120kg, respectively. Saliva samples of all males were collected at 75, 105 and 150 days of age and skin lesions evaluated at 75, 90, 105, 125 and 150 days of age. Three more saliva samples and 2 skin evaluations were performed from the pigs of the SM treatment that remained in the pen after each slaughter batch. Behaviour was recorded by direct and video recording six times (between 85 and 155 days of age). Time budget was assessed by scan sampling every 10min, whereas focal sampling of all pigs in a pen was also performed to record all aggressive events and mounts or attempts to mount the 8min in between the 2 scans. Pigs were individually weighed and loin and backfat measured every three weeks, and individual feed intake automatically recorded during the entire fattening period (73–155 days of age). Carcass skin lesions were assessed. No significant differences between MP and WF pigs in time budget nor on sexual or agonistic behaviour nor performance data were observed. Cortisol levels did not significantly differ between WF and MP pigs, but a significant increase over time (P<0.05) was observed for SM slaughtered pigs (for both MP and WF pigs). After both SM batches, more skin lesions on the remaining pigs were recorded in the MP compared to WF pigs (P<0.01 and P<0.1, respectively). In accordance, a significantly higher incidence of carcass skin lesions was found for MP and SM pigs compared to WF and PW (P<0.01 and P<0.05, respectively). The present results suggest that the welfare benefits (i.e. lower skin lesions) of a WF system were mainly associated with an easier hierarchy reestablishment after SM, but no other long term effects during the rest of the fattening period were observed.

Wealth-dependent and interdependent strategies in the Saami reindeer husbandry, Norway

It has been argued that decisions in relation to choosing strategies to a large degree depend on an organism's state. For nomadic pastoralists, wealth is an important state variable since it has been argued that differences in observed behaviours reflect alternative strategies dependent on varying socioeconomic circumstances. From a game theoretical point of view, however, strategies are also interdependent, i.e., the choice of a strategy cannot be made wisely without considering what other actors are doing since the outcome of a given strategy is dependent not only on individual state but also on the strategies of others. This study investigated to what degree slaughter strategies in the Saami reindeer husbandry are both state dependent and interdependent. The main findings in this study were that (a) the probability, (b) the amount, and (c) the type of animal slaughtered to a large degree were influenced by both individual herders’ herd size and the number of animals slaughtered by neighbouring herders. Moreover, this study also found that kinship represents a coordinating principle since the degree of genealogical relatedness had a positive effect on the slaughtering strategies adopted by herders.

Effect of housing system, slaughter weight and slaughter strategy on carcass and meat quality, sex organ development and androstenone and skatole levels in Duroc finished entire male pigs

This study aimed at evaluating the effect of housing system (HS), slaughter weight (SW) and strategy (SS) on carcass a nd meat quality, sexual organ development and boar taint in entire males. Twelve pens of 10 pigs were used (two trials). Half of male pens were allowed visual contact with females (MF) and half with males (MM). Half MM or MF were slaughtered at 105 or 130kg in trial 1, or penwise or by split marketing in trial 2 at 120kg. Housing system showed no significant effect on carcass or meat quality. MF presented significantly longer testicles and heavier bulbourethral glands compared to MM. The distribution of androstenone and skatole levels was affected by SW but not by HS or SS, samples with androstenone >1μg/g of the different groups falling within the range of 16 to 22%. All correlations between androstenone and sex organs were significant. Housing system and slaughter strategy did not reduce the risk of boar tainted carcasses.

Mass vaccination as a complementary tool in the control of a severe outbreak of bovine brucellosis due to Brucella abortus in Extremadura, Spain

We report the evolution of an outbreak of bovine brucellosis ( Brucella abortus) in the region of Extremadura (Spain) involving more than 1000 herds and nearly 40,000 animals. S19 vaccination of young cattle combined with a test and slaughter strategy did not result in a rapid decrease in herd prevalence and animal incidence; these parameters showed a constant decreasing trend only when a combination of restriction of cattle movements, increased test frequency, S19 vaccination and mass RB51 vaccination (with yearly revaccinations) were applied to all susceptible populations. These measures were applied for 5 years; abortions following RB51 vaccination of pregnant cows were limited to the first inoculation and the involvement of the vaccine strain could only be demonstrated in 78 out of 897 abortions. Our results demonstrate the usefulness – and lack of significant side effects – of RB51 mass vaccination as a complementary tool to control bovine brucellosis outbreaks in areas where the disease cannot be contained using more conservative approaches.

Field Evaluation of the Efficacy of Mycobacterium bovis Bacillus Calmette-Guérin against Bovine Tuberculosis in Neonatal Calves in Ethiopia

In developing countries, the conventional test and slaughter strategy for the control of bovine tuberculosis is prohibitively expensive, and alternative control methods such as vaccination are urgently required. In this study, the efficacy of Mycobacterium bovis bacillus Calmette-Guérin (BCG) for protection against bovine tuberculosis (bTB) was evaluated in Holstein calves under field conditions in Ethiopia. Thirteen neonatally vaccinated and 14 control calves were exposed for 10 to 23 months to skin test reactor cows. Gamma interferon (IFN-γ) testing, comparative intradermal tuberculin testing, postmortem examination, and bacteriological culture were used for the evaluation of BCG efficacy. The overall mean pathology score was significantly (P < 0.05) higher in control calves than in vaccinated calves. Culture positivity for Mycobacterium bovis was higher in the control calves than in the vaccinated calves, and significantly more BCG-vaccinated animals would have passed a standard meat inspection (P = 0.021). Overall, the protective efficacy of BCG was between 56% and 68%, depending on the parameters selected. Moreover, by measuring gamma interferon responses to the antigens ESAT-6 and CFP-10, which are present in M. bovis but absent from BCG, throughout the experiment, we were able to distinguish between vaccinated animals that were protected against bTB and those animals that were not protected. In conclusion, the present trial demonstrated an encouraging protective effect of BCG against bTB in a natural transmission setting in Ethiopia.

Detection of bovine tuberculosis in herds with different disease prevalence and influence of paratuberculosis infection on PPDB and ESAT-6/CFP10 specificity

Bovine tuberculosis (BTB) is a major animal health problem with zoonotic implications. Current control programs are based on test and slaughter strategies utilizing skin tests with tuberculins as antigens. The low specificity and associated operative difficulties of these tests have driven the search for new antigens and diagnostic assays. In this multicenter study, using herds from Argentina, Mexico and Northern Ireland, we selected skin test positive and negative animals from herds with different prevalence's of BTB and compared tuberculin (PPDB) and ESAT-6 + CFP10 as antigens ex vivo. In low prevalence herds, crossreactivity of PPDB was apparent since up to 60% of the PPDB skin test and ex vivo positive animals did not responded to ESAT-6 + CFP10 ex vivo. The superior specificity of ESAT-6 + CFP10 was confirmed in a Mycobacterium avium sp. paratuberculosis infected herd where several of the animals had strong crossreactivity to PPDB and PPDA but not to ESAT-6 + CFP10. In high prevalence herds 85% of the skin test-positive animals, were confirmed ex vivo using either PPDB or ESAT-6 + CFP10 as antigen. However, within this group 60% of the skin test negative animals were PPDB and ESAT-6 + CFP10 positive ex vivo indicating that the skin test can in some herds yield a significant number of false negative results. In conclusion, the ex vivo test is recommended as an ancillary test to accelerate BTB eradication. In high prevalence herds, PPDB or ESAT-6 + CFP10 can be used as antigen whereas in low and medium prevalence herds ESAT-6 + CFP10 is the preferred choice.

Multi Criteria Decision Making to evaluate control strategies of contagious animal diseases

The decision on which strategy to use in the control of contagious animal diseases involves complex trade-offs between multiple objectives. This paper describes a Multi Criteria Decision Making (MCDM) application to illustrate its potential support to policy makers in choosing the control strategy that best meets all of the conflicting interests. The presented application focused on the evaluation of alternative strategies to control Classical Swine Fever (CSF) epidemics within the European Union (EU) according to the preferences of the European Chief Veterinary Officers (CVO). The performed analysis was centred on the three high-level objectives of epidemiology, economics and social ethics. The appraised control alternatives consisted of the EU compulsory control strategy, a pre-emptive slaughter strategy, a protective vaccination strategy and a suppressive vaccination strategy. Using averaged preference weights of the elicited CVOs, the preference ranking of the control alternatives was determined for six EU regions. The obtained results emphasized the need for EU region-specific control. Individual CVOs differed in their views on the relative importance of the various (sub)criteria by which the performance of the alternatives were judged. Nevertheless, the individual rankings of the control alternatives within a region appeared surprisingly similar. Based on the results of the described application it was concluded that the structuring feature of the MCDM technique provides a suitable tool in assisting the complex decision making process of controlling contagious animal diseases.

Applying precision feeding techniques in growing-finishing pig operations

The high cost of feed ingredients, the use of non-renewable sources of phosphate and the dramatic increase in the environmental load resulting from the excessive land application of manure are major challenges for the livestock industry. Precision feeding is proposed as an essential approach to improve the utilization of dietary nitrogen, phosphorus and other nutrients and thus reduce feeding costs and nutrient excretion. Precision feeding requires accurate knowledge of the nutritional value of feedstuffs and animal nutrient requirements, the formulation of diets in accordance with environmental constraints, and the gradual adjustment of the dietary nutrient supply to match the requirements of the animals. After the nutritional potential of feed ingredients has been precisely determined and has been improved by the addition of enzymes (e.g. phytases) or feed treatments, the addition of environmental objectives to the traditional feed formulation algorithms can promote the sustainability of the swine industry by reducing nutrient excretion in swine operations with small increases in feeding costs. Increasing the number of feeding phases can also contribute to significant reductions in nutrient excretion and feeding costs. However, the use of precision feeding techniques in which pigs are fed individually with daily tailored diets can further improve the efficiency with which pigs utilize dietary nutrients. Precision feeding involves the use of feeding techniques that allow the provision of the right amount of feed with the right composition at the right time to each pig in the herd. Using this approach, it has been estimated that feeding costs can be reduced by more than 4.6%, and nitrogen and phosphorus excretion can both be reduced by more than 38%. Moreover, the integration of precision feeding techniques into large-group production systems can provide real-time off-farm monitoring of feed and animals for optimal slaughter and production strategies, thus improving the environmental sustainability of pork production, animal well-being and meat-product quality.

Benefit-cost analysis of vaccination and preemptive slaughter as a means of eradicating foot-and-mouth disease.

To assess relative costs and benefits of vaccination and preemptive herd slaughter to control transmission of foot-and-mouth disease (FMD) virus (FMDV). 2,238 herds and 5 sale yards located in Fresno, Kings, and Tulare counties of California. Direct costs associated with indemnity, slaughter, cleaning and disinfecting livestock premises, and vaccination were compared for various eradication strategies. Additional cost, total program cost, net benefit, and benefit-cost value (B/C) for each supplemental strategy were estimated, based in part on results of published model simulations for FMD. Sensitivity analyses were conducted. Mean herd indemnity payments were estimated to be dollars 2.6 million and dollars 110,359 for dairy and nondairy herds, respectively. Cost to clean and disinfect livestock premises ranged from dollars 18,062 to dollars 60,205. Mean vaccination cost was dollars 2,960/herd. Total eradication cost ranged from dollars 61 million to dollars 551 million. All supplemental strategies involving use of vaccination were economically efficient (B/C range, 5.0 to 10.1) and feasible, whereas supplemental strategies involving use of slaughter programs were not economically efficient (B-C, 0.05 to 0.8) or feasible. Vaccination with a highly efficacious vaccine may be a cost-effective strategy for control of FMD if vaccinated animals are not subsequently slaughtered and there is no future adverse economic impact, such as trade restrictions. Although less preferable than the baseline eradication program, selective slaughter of highest-risk herds was preferable to other preemptive slaughter strategies. However, indirect costs can be expected to contribute substantially more than direct costs to the total cost of eradication programs.

Modeling alternative mitigation strategies for a hypothetical outbreak of foot-and-mouth disease in the United States

Alternative mitigation strategies were compared during hypothetical outbreaks of foot-and-mouth disease (FMD) in the USA using a computer-simulation model. The epidemiologic and economic consequences were compared during these simulated outbreaks. Three vaccination and four slaughter strategies were studied along with two speeds of FMD virus spread among three susceptible populations of animals. The populations represented typical animal demographics in the United States. The best strategy depended on the speed of spread of FMD virus and the demographics of the susceptible population. Slaughter of herds in contact with known contagious herds was less costly than slaughtering only contagious herds. Slaughtering in 3 km rings around contagious herds was consistently more costly than other slaughter strategies. Ring vaccination in 10 km rings was judged more costly than slaughter alone in most situations. Although early ring vaccination resulted in lower government costs and duration in fast-spread scenarios, it was more costly when vaccinated animals were slaughtered with indemnity and other related slaughter costs.