From: Nell, A.J. [A.J.Nell@IAC.agro.nl] Sent: 03 July 2001 12:13 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: Introduction of a new session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dear Participants, The E-Conference is making good progress and we have already and are still receiving many contributions. The discussion on the topic Nutrient and Manure Management is not yet finished and more messages are coming in. However, between now and August 3rd we still have 4 more topics to discuss and it is time to introduce a new session. Later today we will introduce the next topic for the E-Conference on Animal and Public Health with the presentation of the paper: Area-wide integration and its implications for animal and human health. The paper is prepared by Ranald Cameron, Hussni Mohammed and David Ward. Ranald Cameron and Hussni Mohammed will the moderators of this session. The discussion on Nutrient and Manure Management will continue at least till the end of the week which means that we will be simultaneously discussing more than 1 topic. In order to facilitate the moderation of the E-conference and hopefully keep some order in the discussions I request the participants to adhere to the following rules: 1. Send your contributions to the address: LEAD-AWI-ECONF-L@mailserv.fao.org (DO NOT USE the REPLY BUTTON, this will create unnecessarily long messages and your messages will not reach all moderators). 2. Indicate clearly in the subject bar of your message the topic of the session to which you are sending a contribution (either "manure management" or "health" ) 3. Be as brief and specific as possible (reduce the length of the contribution to 1/4 or 1/2 page) and stick to the topic of the session and the conference 4 Present relevant experiences in the form of case studies After the current sessions we will have 4 more sessions coming: - Livestock production in a spatial analysis and planning context (9 July) - Social Aspects (16 July) - Economics and policy options (23 July) - Concluding forum (30 July - 3 August) Thank you very much for your interest in the conference, for submitting so many contributions and your good co-operation. I look forward to the rest of the conference. I wish you an interesting continuation of the conference kind regards Arend Jan Nell Conference Moderator From: Narrod, Clare (AGAL) Sent: 03 July 2001 13:10 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: WELCOME MESSAGE FOR ANIMAL AND HUMAN HEALTH DIS CUSSION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dear participants, The impacts of livestock production on the environment have to be taken very seriously because they can threaten not only the long-term productivity of agricultural and livestock activities but also on animal and human health. To be sustainable, livestock production therefore has to pay great attention to the prevention or minimisation of its environmental impacts. The development of large-scale intensive animal production systems, although often very profitable, and able to produce large quantities of food of consistent quality efficiently, can result in serious animal and human health problems, raise concern for animal welfare and may result in environmental pollution due to the large quantities of waste products(effluent)produced. Animals raised in dense concentrations, sharing limited space or intensive housing systems, together with the demands for high levels of productivity are at risk of disease outbreaks or propagation and amplification of animal and human pathogens. These same intensive livestock production systems release large quantities of effluent (faeces, urine, waste water and unconsumed feed) that can carry a variety of potential animal and human pathogens. Additionally, effluents can concentrate inorganic and organic agro-chemicals or their residues, which may have recognised safe intake or application levels, but which may exceed these safe levels and pose a hazard for human health. To kick off the discussion the paper formulates a number of key-questions that should be discussed. We suggest the participants to react to as many of the key-questions as possible. At the end of the week we will summarise the discussion, highlight the key aspects and propose some conclusions. We hope to have an open and critical discussion and invite everybody to participate regularly and actively in the discussion. We thank you for openly sharing all your experience and for your critical remarks in the discussion. The moderators Ranald Cameron Hussni Mohammed From: Narrod, Clare (AGAL) Sent: 03 July 2001 13:29 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: PAPER FOR ANIMAL AND HUMAN HEALTH DISCUSSION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ AREA WIDE INTEGRATION (AWI) AND ITS IMPLICATIONS FOR ANIMAL AND HUMAN HEALTH Ranald Cameron, Hussni Mohammed & David Ward Area wide integration (AWI) is a concept whereby a particular livestock activity, e.g. pigs, poultry or cattle raising, is integrated with some form of crop farming in a specific area not used for other livestock production and generally a long distance away from densely populated urban development. The purpose of such integration is to maximise the benefits, spread benefits (and risks) equitably and manage environmental, human and animal health risks. This paper will discuss AWI in relation to human and animal health issues arising from this concept. ANIMAL AND HUMAN HEALTH HAZARDS The development of large-scale intensive animal production systems, although often very profitable, and able to produce large quantities of food of consistent quality efficiently, can result in serious animal and human health problems, raise concern for animal welfare and may result in environmental pollution due to the large quantities of waste products (effluent) produced. Animals raised in dense concentrations, sharing limited space or intensive housing systems, together with the demands for high levels of productivity are at risk of disease outbreaks or propagation and amplification of animal and human pathogens. These same intensive livestock production systems release large quantities of effluent (faeces, urine, waste water and unconsumed feed) that can carry a variety of potential animal and human pathogens. Additionally, effluents can concentrate inorganic and organic agro-chemicals or their residues, which may have recognised safe intake or application levels, but which may exceed these safe levels and pose a hazard for human health. Q1 What are some important animal and human health hazards (risks) of concern arising from large-scale intensive animal production units? What differences in hazards (risks) exist between large-scale, intensive and smallholder animal production systems? MANURE AND EFFLUENT AS SOURCES OF PATHOGENS On-farm manure treatment and disposal vary greatly between temperate and tropical conditions in terms of control of microbial pathogens. Manure composting treatment in the wet tropics may have little or no lethal or inhibitory effect on pathogenic micro-organisms when present. Under both conditions, the health protecting benefits of high dilution rates can be lost when too large quantities of effluent need disposing of from intensive production units. Existing methods of treatment by anaerobic fermentation and methanogenesis require large fermentation vessels for biogas and/or methane production and capture, or liberate methane and carbon dioxide into the atmosphere as greenhouse gas emission. Some of these methods are costly and not effective. The survival of pathogens in animal waste treatment systems may present serious problems of environmental pollution and public health if the waste is discharged into rivers, streams or contaminates groundwater. Pathogens may be amplified in one livestock raising system and then infect another species when manure is mixed with feed. Animal health may be adversely affected if recycled waste-water is re-used in washing animal housing, for further flushing of effluent or for irrigation of pastures or food crops. As agronomic areas are more compressed and the proximity of animal production units comes closer to areas used to grow crops that receive minimal processing, such as fresh produce, the potential for contamination of irrigation water or soils and subsequent cross-contamination of food crops increases. Increasingly water- and food-borne disease outbreaks are being associated with the use of contaminated irrigation water or manures containing microbial pathogens. Other health risks can result from the excessive use of antibiotics, antimicrobial agents, growth promotants, hormones, etc. used in an attempt to control disease. If used incorrectly or not strictly controlled, these can become residues in meat and milk products and/or produce antibiotic resistant animal or human pathogens. Q2 Considering the different options for manure management in relation to the spread of pathogens, what are the most cost-effective strategies for small holders? In times of shrinking resources, how can small holders be helped in making economically viable decision? We recognize the fact that there are a wide variety of farms depending on their size. They vary in their resources in terms of access to capital, skilled labor, land and resources, management ability, and market. These resources play a major role in their decision to adopt a manure management practice. These practices include daily spreading, storage, odor control, solid separation, composting, biodrying, anaerobic digestion, high solids anaerobic digestion, and lagoon treatment. However, depending on the perception about their personal values and available resources, each farm can have a different environmental concern. Farms in watershed areas might perceive that controlling waterborne pathogens should be a priority in their manure management decision. On the other hand, farms that use or sell manure as fertilizer might perceive controlling food-borne pathogens as a priority. The range of pathogens span from bacterial e.g., E. coli O157:H7, Campylobacter jejuni, Salmonella spp., Leptospira spp., Listeria spp., and Shigella spp.); protozoan (e.g., Cryptosporidium spp. and Giardia spp.), human viruses (e.g., Hepatitis A, and Norwalk virus). The public health risk associated with water and food borne pathogens depends on factors related to the pathogen itself, the environment in which it survives, and the host that it infects. All these factors have to be taken into consideration when a choice between manure- management practices is made in relation to the farm resources. Generally, smallholders have limited resources. The challenge is to help them building capacity to meet theirs and public health expectation in terms of AWI. Options to be considered in the building capacity could include a three tier approach. This approach take into consideration the potential import of pathogens into the operation, strategies to minimize the perpetuation of the pathogens in the operations, and minimizing the output of microbial load. Pathogens can be imported into farms by infected animals, contaminated feed, water, vehicles, and equipment. Strict biosecurity system might help in reducing this risk. Sound management practices will no doubt reduce the risk of perpetuation and amplification of organisms on farms. The adoption of a cost- effective biosecurity measures and implementation of best management practices will positively impact total output load of pathogens from farms. Q3 What data are required to carry out a useful environment cum pathogen impact analysis of hazards arising from animal effluent from intensive or smallholder animal production units? AGENTS CAUSING DISEASE IN HUMANS BUT NOT IN ANIMALS The development and implementation of cost-effective strategic plans to control and manage the potential risk to water and food supply from pathogenic organisms in animal waste depends largely on understanding the sources of these agents, the mechanism by which they are introduced into animal populations and the factors that play a role in their perpetuation on the farm. Such plans can only be developed through integrated and valid research, education, and extension approaches. There are several endogenous and exogenous sources of these pathogens that contribute to the risk of environmental degradation. Controlling these endogenous and exogenous sources will no doubt reduce the potential contribution of animal wastes to the degradation of environmental quality and public health. Highly successful waste treatment processes and strategies have been developed to kill or inactivate microorganisms. However, it is suggested that the variety and concentration of potential pathogens in animal effluent is best controlled by developing and maintaining animal populations free of specific pathogens at the outset. Healthy, disease free livestock will have significantly less pathogens in their waste. This is important as many of these food-borne disease outbreaks result from micro- organisms (e.g. E. coli 0157, Cryptosporidium parvum, Campylobacter jejuni, and Salmonella spp.) that are pathogenic to humans but do not necessarily cause visible signs of disease in animals. Although the proposal is appealing its cost-effectiveness has to be compared to alternative approaches. Q4 Who should bear the cost of eliminating diseases of humans that do not cause measurable, even so-called sub-clinical, production losses in animals? ZOONOTIC DISEASES Conversely, there are recognised pathogens causing clinical disease in animals as well as frank disease in humans. These are termed zoonotic diseases and over 300 separate such zoonotic diseases are recognised. Some of the reasons for an increasing occurrence of zoonotic diseases are thought to be: 1) physical alteration of the environment which brings humans into more intimate contact with certain animal species, vectors, and transmitters of infectious agents; 2) increasing human populations favouring an increased level of contact between humans and infected animals; 3) changes in food processing and consumer nutritional habits; and, 4) increasing movements of people as well as trade of animals and animal products and decreasing activities for the surveillance and control of major zoonoses (Meslin 1997). ONE PROPOSED SOLUTION: SPECIFIC PATHOGEN FREE ANIMALS Intensive animal production systems have an enhanced potential for disease outbreaks due to: * the build up and amplification of pathogens in their environment; * vertical and lateral spread through close contact, especially between different age groups; * stress associated with high stocking densities, inadequate ventilation and poor temperature control, handling and transport; * difficulty in maintaining adequate levels of hygiene due to continual presence of animals - inability to systematically depopulate and break cycles of infection; and * multi-factorial disease complexes due to interaction and/or synergism of new risk factors with endemic organisms and susceptible hosts. Health management in intensive pig production systems, because of its extreme complexity, is one model to use when considering the animal and human health aspects of AWI. For AWI of pig production systems to be economically successful and at the same time minimise the risks associated with disease outbreaks and public health implications, the following criteria are essential. 1. Establishing the populations from the outset with specific pathogen free(SPF) breeding sows. Further introductions of new genetics must be by SPF pigs, artificial insemination or embryo transfer. 2. Isolation and biosecurity to avoid introduction of disease. 3. All-in-all-out, multi-site, batch pig husbandry systems. 4. Enhancing herd immunity through strategic vaccination, deworming programmes and adequate nutrition. 5. Specialist veterinary service with access to diagnostic backup. 6. Using an efficient method of effluent treatment to kill, inactivate and/or dilute all potential pathogens. Q5 Are SPF animal production methods cost effective? At what scale of production? Would the extra costs required to raise animals free from specific human pathogens (e.g. E. coli 0157 or cryptosporidia) be justified and who should pay or share the costs? Which animal species might lend themselves best to being raised specific pathogen free and at the same time cost effective - pigs, poultry or ruminants? AWI FOR ENHANCING BIOSECURITY AND DISEASE CONTROL AWI will allow isolation of different livestock production units so that strict biosecurity can be maintained. Breakdowns in biosecurity not only affect the animals' health and economic viability of the production system but also pose threats to human health. Biosecurity encompasses all aspects of avoiding the introduction of disease and requires detailed attention to: * Perimeter fencing to keep out other animals, vehicles and people. * Specific protocols for staff and visitors entering the production (or growout) area with regards to changing clothing, showering in and being aware of downtime after contact with other livestock. * Supervision of vehicles and their drivers delivering feed or loading finished livestock for slaughter. * Use of a quarantine facility for isolation and acclimatisation for incoming animals. * Ongoing training of staff in all aspects of biosecurity and health management. All-in-all-out management allows efficient hygiene and some control over a specific breakdown as affected groups are isolated and can be treated or eliminated as appropriate. It also eliminates the problems associated with mixing of age groups and vertical spread of disease. In addition multi-site production systems help to cater for changes in levels of disease status in breeding herds which can be managed without total depopulation if a pathogen is introduced. Depending on the pathogen, early weaning can further reduce the risk of high levels of infection in batches of weaned pigs. Together, multi-site and all-in-all-out production allows disease outbreaks to be contained within a given room or building or site without compromising the health status of the entire population. Q6 If AWI concepts can enhance biosecurity, can this be achieved successfully for rural smallholders at the village level? How can livestock services be delivered effectively (in biological terms) and cost effectively to small holders at village level? AWI AFFECT ON DELIVERY OF ANIMAL HEALTH, NUTRITION AND RELATED SERVICES Sound animal health management provided under the direction of experienced veterinarians should aim for economical disease control, elimination of catastrophic losses from disease, ensuring product quality and safety and advising mangers on public and environmental health risks. Rapid diagnostic back up, provided by the public or private sectors, is essential for the early detection of disease, especially diseases that could be a public health risk. Nutritionists, veterinarians, breeding advisors, marketing agents and civil engineers as well as bankers, can all have essential roles as team members to advise or directly assist managers of intensive livestock units. The concentration of livestock and capital both make hazards, be they animal or human diseases or environmental pollution, more expensive. These risks are best managed by a team of specialists. At the same time, the geographical concentration of more intensive livestock units reduces the transaction costs to deliver services and inputs. Likewise, the opportunities to manage risks in an economical manner may well be brighter in intensive, concentrated livestock units. Q7 In what ways would AWI affect delivery of animal health, nutrition and related services? Who should pay for services provided for animal health, nutrition, breeding and the like? Are there both public and private goods involved in having these services available so that costs could be shared? From: Rosales, Mauricio (AGAL) Sent: 04 July 2001 13:42 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Peter Henry on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Peter Henry from Queensland, Australia describes a newly developed manure treatment technology with different steps. The prototype unit has been successfully run for 3 years in Australia. He estimates the costs at 10-15% added to the capital cost of a modern large scale piggery (1000 sows; does this include running costs? - moderators). It would be interesting to check if this cost frame also holds for developing countries. Furthermore we invite Peter Henry to also comment how he judges the reliability of the system on farms in developing countries and what he considers a minimum size for a reasonable use of this system. The major advantages of this prototype are: removal of all pathogens, odour, and providing recyclable water that can be used as washing water in animal houses. It also has the advantage of providing a source of protein for animal food as well as by-products suitable for agriculture such as a fertiliser and soil conditioner. It is designed for medium to large intensive animal production systems and could solve the problems of waste management associated with both existing and future intensive animal production in developing countries. The system is so complete in the treatment of waste that it could solve problems of intensive animal production systems which have been forced to establish close to urban areas where infrastructure exists. (See the comments of Dr John Niezen - manure management - in relation to the spread of intensive urban livestock production in West Africa). It also could solve the problem of spreading pathogens in areas integrated with crop production. One of the moderators believes it is inevitable such a system will be adopted in the near future in developed countries pending stricter environmental regulations. Moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From Peter Henry We have developed a process which we believe solves the problems associated with the effluents of large intensive animal production units. It is based on acidogenic not methanogenic fermentation. Our process which draws from a model of ruminant digestion: * converts complex wastes into the chemically simpler compounds of ammonium and volatile fatty acids(VFA). * kills bacterial pathogens such as Salmonella and Escherichia coli. * Minimises water volume required for waste treatment. * Removes malodour from gases and liquids. * Provides deodorised water for recycling as wash water. * Requires a relatively small area to accommodate the plant. * Does not produce hydrogen sulphide (H2S is not a byproduct of acidogenesis). * Can provide a high protein concentrate as single cell protein. * Alternatively can precipitate N and P as magnesium ammonium phosphate (MAP) for use as fertiliser. * Provides a stabilised bacterial pathogen-free lignocellulosic sludge for use as a soil conditioner. * Does not accumulate indigestible sludge in tanks or ponds (If sludge accumulates in ponds its subsequent removal is a major unsolved problem in large piggeries). * Is continuous and treats each day's output of manure during the succeeding eight days. The process is described as follows: 1. A flooring system has been developed which permits the urine,faeces, spilt feed and wash water to be flushed from the piggery daily. 2. The slurry is passed over a self-cleaning screen, also developed in Australia. This concentrates the solids and permits their accumulation in a collection tank. The process depends on a 6-8% content of solids. This can be controlled by the addition of a determined volume of the filtered liquid. Salts necessary for the fermentation and contributed by the urine are thus added to the screened solids. 3. The concentrated slurry is then fed into an acidogenic fermentation system. The hydrolytic,fermentative,acid-forming, fast growing bacteria derived from the large bowel of the animals ferment the carbohydrate present in the waste to straight-chain VFA C2-C8. The proteins are deaminated to form branch chain VFA and ammonium. During a four day fermentation a concentration of 150mM VFA is obtained. The short residence time, high solids, and acid conditions, pH 5.7-6.2, mean that carbon is channelled into VFA and methanogenesis is inhibited. The fermentation precipitates Fe,Cu and Zn, the heavy metals which have been fed to pigs for nutritional reasons. 4. The fermented liquor passes to an acidification tank where the pH is lowered to 4.3. This converts most of the VFA to the undissociated form. VFA in this form kill the enterobacteriaceae such as Salmonella and E.coli, as well as Campylobacter, Brachyspira and Leptospira, all organisms commonly found in pig populations, many capable of infecting humans. Other susceptible organisms are Staphylococcus aureus,Pasteurella multocida and Vibrio cholerae. My colleague Ivor Harris has shown in his rate studies that Salmonella and E.coli are killed in 3 hours by acidogenically fermented pig waste liquor at 30 degrees C containing 150mM VFA. Our group has demonstrated that VFA destroy some viruses but more work needs to be done in this area. The eggs and larvae of ascarids (round worms) are resistant to VFA. Clare Narrod mentions BSE. It may be that the rapid deamination of protein by acidogenic fermentation may be useful in damaging the prion of BSE. This too needs investigation. 5. The stabilised lignocellulosic sludge which remains after fermentation - and this makes up about 50% of the original total solids - is screened from the liquor. It has value as a soil conditioner and containing lignin it has a high calorific value. 6. There are alternatives available for treating the fermented liquor, now freed of bacterial pathogens and indigestible solids, but rich in VFA and ammonium: 6(a) A pellicle-forming yeast, Candida ingens (perfect form Pichia humboldtii), utilises VFA as its carbon source and ammonium as N. It also accumulates P. If an array of vertical curtains is inoculated with the yeast and the waste liquor trickled down the curtains, the result is a dense microbial lawn dominated by the yeast but containing many symbiotic bacteria and discrete yeasts caught up in the pellicle. The lawn is self-sloughing and has a high nutrient value as a protein concentrate. (This process was developed at the University of Queensland. The intellectual property was sold to an agribusiness company for commercial development, so parts of the process are subject to licencing considerations although other parts are in the public domain). 6(b) It is possible to use the biological nutrient removal (BNR) pathway common in sewage treatment plants where the fermented liquor is aerated and utilised by organisms which accumulate N and P in the presence of VFA. 6(c) A third possibility is to feed the VFA-rich liquor into a methane bioreactor. This may be more complex than earlier treatments as these will be large plants and production of hydrogen sulphide will occur as part of the methanogenic process. Scrubbing out this compounds would be essential. I am personally nervous about large scale methane production in a farm situation because fire and explosion are such a hazard. 6(d) There is still considerable N and P remaining in the liquor which never entered the fermentation process. Urine will have contributed greatly to this. A Queensland municiple engineer has published a paper describing the production of magnesium ammonium phosphate (MAP) from sewage liquors. It is proposed to use the MAP as a fertiliser. This is not a new development. The chemical reaction which forms MAP is discussed in my 1939 school chemistry text. We operated an acidogenic fermentation of piggery wastes for three years at a 1500L/day pilot plant at a 1000 sow piggery. The fermentation is stable and therefore reliable.The duration of treatment is 8 days and operates on a continuous basis. Capital costs will vary from country to country, depending on their manufacturing capacity and what has to be imported. If the alternative (b) is used - the BNR technology following acidogenic fermentation - a starting point for costing should be in the region of 10-15% added to the capital cost of a modern large scale piggery (1000 sows). Modern intensive animal production is an advanced technology involving environmentally controlled buildings, high nutritional standards, automated feeding, the latest reproductive techniques, the application of genetics and rigorous prophylaxis and disease control. It is absolutely necessary that modern waste treatment methods be included in the management process. The process meshes with the establishment of minimal disease piggeries a topic to be examined during the conference under the moderation of Ranald Cameron. This waste treatment process has application to the concept proposed by FAO for Area Wide Integration of Crop and Livestock Production. Details and references can be supplied when needed. Peter Henry, Division of Veterinary Pathology and Anatomy School of Veterinary Science, University of Queensland, Australia, veterinarian. From: Ranald Cameron [r.cameron@magnet.com.au] Sent: 06 July 2001 09:49 To: AWI email Subject: LEAD-AWI-ECONF-L:Message from moderator Dear E-conference participants The development of large scale intensive animal production systems have taken place in both developed and developing countries. It is well recognised that they can create risks both to the health and welfare of the animals and possibly amplify the transmission of human pathogens. It has been shown in a number of countries that these risks can be significantly reduced by establishing and maintaining (with strict biosecurity) production with disease free animals. What are the important animal and human health risks associated with intensive animal production? Can they be reduced to an acceptable level in developing countries? Is the cost justified by the improvement in efficiency of production, reduced mortalities, elimination of the need for costly antibiotics etc. and a lower risk to human health? In comparison what is the actual health status of animals on small scale farms — do we know? Can they pose a similar risk to animal and human health? The previous discussion on manure management has made little reference to both animal and human pathogens, their origin and importance. Can we justify systems that can transport/spread manure over large areas/farm to farm, without first removal of all pathogens? How important is a knowledge of the type/prevalence of pathogens at the source of origin – the animals? Is there a difference in small and large production units in the health status of the animals? Which effluent treatment systems actually kill/inactivate all pathogens? Is elimination of all pathogens an essential pre-requisite of any manure management system? An initial capital outlay will be inevitable to establish and maintain animal production units free of pathogens that are a risk to both animal and human health. Who should provide this capital - the producer or government? Could there be a government loan to be paid back out of the income from improved production and performance? Is government support warranted in the interest of public health? Ranald Cameron From: Rosales, Mauricio (AGAL) Sent: 09 July 2001 11:50 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Wim Tondeur on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Wim Tondeur has highlighted some very important points regarding animal health and disease transmission. He has clearly indicated concerns in relation to the spread of animal diseases and aspects pertaining to their health and the problem of transporting manure and using it for crop production. He also discusses the separate issue of zoonotic pathogens and highlights the many ways in which they can be transferred from animals to humans. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Wim Tondeur Dear fellow participants, I would like to comment on this topic by covering four aspects: 1. Highly contagious and very-pathogenic diseases (e.g. Hog Cholera, Foot and Mouth Disease and Aujeszky's Disease). This group of diseases is only of importance to the animal's health. These diseases are notifiable in many countries and included in programs of eradication. Veterinary agreements between countries always use phrases such as "certified free of CSF, FMD, ADV, Brucellosis, ....) However there are still many outbreaks reported and even in some areas these diseases are endemic. Manure, slurry and waste-water originating from infected premises should never be transported to other places, including farmland for crops. Incinerating of solid manure and heating of slurry is the best option. 2. The common zoonotic pathogens: (Salmonella, Shigella, Campylobacter, Entamoeba, Helminthes, Leptospira, Staphylococci, Streptococci, certain E. coli - serotypes, etc). The incidence of these pathogens is very high in many places, all over the world. There is however a "natural" balance in humans and animals between these pathogens and the immunity and resistance of the individual. Pig manure and waste-water are potential sources of infection to humans, also via crops, fishponds, vegetables, drinking-water, bathing, washing clothes and rinsing kitchenware in open surface- waters. There are still many other routes of infections for these pathogens like public toilets above fishponds, use of human-faeces as fertilizer in vegetable-gardening, unhygienic restaurants, consumption of raw, uncooked food, cross- contamination in slaughter places, dirty shelves at local markets, etc, etc. That means at different levels action must be taken and may be it is an illusion to achieve a level of 100% no risk at all. Looking at the poor progress in European countries to get meat and meatproducts free of Salmonella and Campylobacter, it means we still have a very long way to go. Or maybe we have to accept to live in close harmony with these pathogens. 3. New problematic zoonotic diseases like Nipah-virus in pigs in Malaysia, Japanese Encephalitis in China and Influenza in Hong Kong. What has happened and is still going on is really worrying the consumers in South East Asia in a very serious manner. Of course there is a political/cultural aspect in these cases, but it is comparable to the BSE and Dioxin cases in Europe. First of all more research, investigations must be carried out to get a better view on the real treat of these pathogens, including the role of manure and waste-water coming from animalfarms. 4. In relation to all the above mentioned pathogens a good monitoring system combined appropriate animal and meat inspection protocols need to be developed, and internationally recognised. Wim Tondeur Chief Technical Advisor at BTRC-IPC project Vietnam From: Rosales, Mauricio (AGAL) Sent: 09 July 2001 12:00 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Additional Comments from the Moderators to Pet er Henry Contribution ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The acidogenic treatment of solid manure in swine farms is an interesting approach. Given the description in the paper, the approach will no doubt be appealing to some farms based on their goal and resources. With increased public awareness of the environmental issues related to the risk associated pathogens in swine manure, there is an increased demand for development of comprehensive management plans that address this risk. There is no doubt a room for such an approach in these plans. Dr. Henry mentioned in his paper a couple of studies on the impact of the undeissociated form of VFA on the survival and viability of the bacteria and viruses; it will be helpful to include the citations in the paper. One of the biggest challenges to the swine industry has been to convince farmers to develop comprehensive nutrients management plans (CNMP) that incorporate pathogen risks. The citations might lend credence to the approach and encourage its utility. Questions? The answer to these questions might have been provided in the citations mentioned in the paper by Dr. Henry. 1) Is there any financial analysis being done on implementation of this system? Dr. Henry mentioned that an estimated additional cost of 10-15% is expected. Can he elaborate on that; is this a fixed cost or a composite average of the variable cost as well? 2) Can Dr. Henry comment on the ease of application and management of the system on the farm? A system that is low cost and easy to manage would have a high acceptability by the farmers. The Moderators From: Rosales, Mauricio (AGAL) Sent: 09 July 2001 20:09 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Halina Zaleski on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Halina Zaleski a swine extension specialist from the University of Hawaii in the US critics the concept of specific-pathogen free animals as a means of disease control and points to the problems associated with the concept. - The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From Halina M. Zaleski There is no such thing as a disease-free animal or disease- free production. What is possible is a specific-pathogen free animal or a minimal disease animal. These are typically derived by a method such as hysterectomy, caesarean section, or medicated early weaning to prevent or minimize the transmission of pathogens from the dam to the offspring after birth. There is no existing method of preventing the transmission of pathogens in utero. Neither is it realistic to raise livestock in sterile, sealed chambers to prevent the transmission of any pathogens from the environment (air, water, feed, people, insects, etc.). Sometimes reducing the number of micro-organisms can have problematic side-effects. Obviously, much of digestion, especially in the rumen, depends on micro-organisms. Less obviously, removing some micro-organisms can allow less competitive micro-organisms to flourish. For example, an increased incidence of exudative epidermatitis has been observed in some specific-pathogen free swine herds. Conversely, reduction of pathogens such as salmonella and potentially E. coli in poultry can be achieved by competitive exclusion, in which the gut micro-organisms from healthy adult birds are orally administered to chicks- these micro-organisms out-compete the pathogens, preventing colonization of the gut by salmonella (researchled by D. E. Corrier, ARS Food Animal Protection Research Lab, College Station, Texas). Similarly, pathogen-free manure is impossible. On the other hand, existing treatments, such as aerobic composting or anaerobic digestion in lagoons or digesters, can greatly reduce the number of pathogens so they end up many orders of magnitude lowEr. The appropriate goal is reduction of pathogens below the minimum infectious dose. Halina M. Zaleski ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Comments from moderators As a follow-up to Dr Halina Zaleski's comments the moderators would like to say that they agree that there is no such thing as a disease free animal or disease free production. Maybe they should have used the words 'animal's free of specific pathogens' in their introduction to the questions on animal health. However there are many minimal disease/high health status animal production systems especially for pigs and poultry. The term 'specific pathogen free' (SPF) is used widely to refer to animals where it is possible to specify and monitor the pathogens they are considered to be free of. The synonymous terms 'minimal disease' or 'high health status' are also widely used and are possibly less confusing. In Australia it has been estimated that more than 50% of the pigs produced for slaughter are from SPF herds, an even greater number of commercial poultry are reared SPF, none are reared in sealed chambers. The pig herds are established either as primary SPF herds by hysterectomy (usually nucleus herds) or as secondary SPF herds (multiplier or commercial) where the original breeding stock come from primary herds . Medicated early weaning or 'isowean' is also commonly used to establish SPF herds. Introduction of genetic material is usually by artificial insemination, occasionally embryo transfer or by reverting back to procuring hysterectomy derived piglets. A number of SPF herds have already been established in SE Asia in particular the Philippines and Indonesia, with SPF breeding stock imported from both Australia and the USA. This already demonstrates that developing countries can adopt these technologies. Further we agree with Dr Zaleski that by removing some micro- organisms others may flourish. We believe that this is one of the reasons why we have seen the recent emergence of Glassers disease in a number of our SPF herds. However as far as exudative epidermitis is concerned it is caused by a pathogen that is difficult to keep out of SPF herds, but as with many of these ubiquitous pathogens immunity rapidly develops and the disease usually disappears. We consider it to be one of the diseases associated with the 'newly established gilt herd'. These usually disappear as the herd ages or can be vaccinated against and cause no significant effect on production. We believe we have an obligation to do everything we can to establish and maintain animal production systems free of as many pathogens as possible and when necessary use vaccines to establish herd immunity. By doing this we not only enhance animal health and improve animal welfare, but contribute in reducing the risk to public health. - Ranald Cameron, Animal Health moderator From: Rosales, Mauricio (AGAL) Sent: 10 July 2001 17:06 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Halina Zaleski on Health Session 2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Halina Zaleski a swine extension specialist from the US presents information on a treatment system for slaughterhouse waste that is used in Hawaii. It sounds like a good idea, however we don't know how applicable it is to the problem of effluent from livestock production. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From Halina M. Zaleski An innovative treatment system is the Living Machine from Ocean Arks International. Check the web page at http://www.oceanarks.org/. This has been used in Hawaii to treat slaughter house wastes with very encouraging results in using nutrients and reducing pathogens. They are currently operating a pilot Living Machine on the island of Oahu in cooperation with: the US Department of Agriculture, the Massachusetts Foundation for Excellence in Marine and Polymer Sciences, PICHTER, the Farmer's Livestock Cooperative, Strategies Hawaii, the Bishop Museum, and the University of Hawaii at Manoa. Located at the Farmer's Livestock Cooperative slaughterhouse in the town of Ewa, the research Living Machine pioneers the transfer of Living Machine technology to Hawaii and the Pacific region, educating local communities, businesses and officials on the opportunities for integrating ecological technologies into agricultural production and waste treatment. The Ewa Pilot Living Machine treats about 3,000 gallons per day of slaughterhouse wastewater to meet Hawaii Department of Health reuse standards (R-2). Ocean Arks is collecting data from the facility to profile the slaughterhouse waste and refine the configuration of future Living Machines for treating larger quantities of slaughterhouse and agricultural waste at other locations. The Living Machine houses a diversity of both micro and macro-organisms that feed on the waste. A variety of complex habitats within the system promotes biodiversity and the formation of ecologically complex food webs. Modelled after natural freshwater aquatic ecosystems, the Living Machine hosts a multitude of beneficial plants and animals, including microbes, higher plants, snails, clams, and fish. Plant racks suspend aquatic plants within the tanks to enable their roots to hang in the water. Roots are a jungle under water that are home to the abundant microbial communities that feed on wastes. Each group of organisms plays a significant role in maintaining functionality and stability in the ecologically engineered system. Biologically diverse ecosystems are robust and resilient. The Hawaii Pilot Living Machine encompasses both species diversification and bioregionality with a wide variety of plants and animals collected from many locations in Oahu. The Bishop Museum and the University of Hawaii have aided in locating collection sites and choosing native Hawaiian and Polynesian plants. Their partnership has enabled this Living Machine to be a sustainable treatment system and educational tool for schools and communities as a small demonstration model for Hawaiian botanicals and their roles in Polynesian culture. Halina M. Zaleski, Ph. D. Swine Extension Specialist University of Hawaii 1955 East-West Road Honolulu, HI 96822-2321 Ph 808-956-7594 Fax 808-956-4883 From: Rosales, Mauricio (AGAL) Sent: 11 July 2001 11:40 To: LEAD-AWI-ECONF-L@mailserv.fao.org Subject: LEAD-AWI-ECONF-L: Comments from Hussni Mohammed on Health Session (2) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hussni Mohammed comments on Wim Tondeur contribution and agrees that a surveillance system is an excellent tool to implement cost-effective intervention strategies to reduce the risk from pathogens. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Hussni Mohammed Wim Tondeur has highlighted some very important points regarding animal health and disease transmission. He has clearly indicated concerns in relation to the spread of animal diseases and aspects pertaining to their health and the problem of transporting manure and using it for crop production. He also discusses the separate issue of zoonotic pathogens and highlights the many ways in which they can be transferred from animals to humans. I agree with Dr. Tondeur that notifiable diseases are national and governments' responsibilities since they have the means and resources to deal with it. Also Dr. Tonduer has listed a number of diseases that have a potential to influence the public health through contamination of water and food. Although the list is inclusive of bacterial organisms that have a potential to be shed in the manure, it has overlooked some of the protozoa that has been in several waterborne outbreaks in some parts of the world. Examples include Cryptosporidium parvum and Giardia sp. Although it is true that we have a long way to go to identify all the potential sources of risks from these pathogens, it was the intent of this AWI conference to start the dialogue about their importance and the means of controlling and managing their risks. I believe that every step will contribute towards the long term goal. By starting an early dialogue may be we will be able to reach a consensus about standardized approach to manage this risk. I agree with Dr. Tondeur that there is a gap in the knowledge about the fate and survival of these pathogens in the environment. This gap has opened the door for speculative statements that fuelled the media and the public concern regarding the risk from animals to the environment. Such concern slows the efforts to develop an AWI. This concern can be alleviated by valid research to provide the data on the perceived risk and proper dissemination of information. The challenge is how to consolidate the research efforts in times of shrinking resources and diverse political interest to promote AWI approach and provide the scientific base for its implementation. The suggestion to implement a monitoring system is well taken. An efficient surveillance system is an excellent tool to implement cost-effective intervention strategies to reduce the risk from these pathogens and assure the public of the safety of the environment. Although the monitoring system should have international standards, it should be adaptable and flexible enough to allow for accommodation of particular need. Hussni Mohammed hom1@cornell.edu From: Rosales, Mauricio (AGAL) Sent: 11 July 2001 19:57 To: LEAD-AWI-ECONF-L@mailserv.fao.org Subject: LEAD-AWI-ECONF-L: Message from the moderators Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The health discussion paper has given considerable emphasis to the risks to public health associated with pathogens in effluent from large scale intensive farming systems. However it should also be remembered that many zoonotic pathogens are commonly found in animals reared on small scale and family farms. For example salmonella spp., E coli 0157, Brucella spp., Leptospira spp., Q Fever, Japanese encephalitis virus, Nipah virus, Cryptosporidium, Toxoplasmosis sp., Campylobacter sp. and Balantidium coli to name a few. Our current knowledge about the risk of these pathogens is that most of these are not necessarily transmitted to humans via manure or effluent but more frequently by direct contact with animals, handling carcasses at slaughter and consuming contaminated products such as meat and milk. We recognize in saying this statement there is a growing literature on the risk from spreading raw manures on fruits and vegetables. Further, many of the serious pathogens that affect animals only (F & M disease, Classical swine fever, Infectious bronchitis, Hemorrhagic septicaemic pasteurellosis) are just as important for the small scale farmer as they are to the large intensive producer, in that they seriously affect the health and productivity of the animals, as pointed out by Wim Tondeur in his response to the animal and human health paper. Most pathogens can be spread from farm by transporting manure, movement of animals, insect vectors (mosquitoes) or simply windborne. The perception is that smallholders cannot afford traditional manure management practices. The moderators would be interested in comments from the participants on their concerns for animal and human health in relation to small scale and family farming. Is there a need within AWI for provision of prevention and control programs e.g., vaccination, parasite control, veterinary services and education? At what cost? And who should pay? Also we would be interested in comments regarding the spread of manure on crops and human health hazards associated with this practice. The moderators From: Rosales, Mauricio (AGAL) Sent: 11 July 2001 20:04 To: LEAD-AWI-ECONF-L@mailserv.fao.org Subject: LEAD-AWI-ECONF-L: Additional Comments from the Moderators to Sand oval Contribution ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dr Sandoval comments on Cheryl McCrindle point of additives in manure. The potential risk to animal fed with diet high in copper is well known. The scenario of copper toxicity presented by Dr. Sandoval is foreseeable. On the other hand, Cu, as a prooxidant, has a potential to cause oxidative injury to the microorganisms in the manure and hence kill them. Therefore, if feeding manure to animals has to be a choice in an AWI program, these issues have to be taken into consideration. The final decision should be based on the cost effectiveness of the choice for the smallholders and the benefit-cost ratio for large-scale operations. The quality assurance approach proposed by Dr. Sandoval could incorporate an on farm management practices, including nutrient management program, to reduce the total maximum daily load of Cu. The moderators From: Rosales, Mauricio (AGAL) Sent: 13 July 2001 14:51 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Harald Menzi on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Harald Menzi from Switzerland has highlighted the dangers of the pollution of both surface and ground water with pathogens from manure and the risks to human health when this water is used for drinking, washing etc. He correctly states that most treatments of effluent cannot be guaranteed to eliminate all pathogens. It is interesting that he states that in Europe the problem is of minor importance simply due to the fact that both prohibition and heavy penalties exist for allowing discharge into water courses. We share his views that potential risk of environmental contamination and sanitary deterioration should be a priority. The strategies he has suggested are commonly employed in the US depending on the resources available to the farmers. Since contamination of watersheds and pollution of the environment are strictly prohibited in Switzerland, it would be interesting to hear from Dr. Menzi who bares the cost of maintaining the pristine of the water and the soundness of the environment. Also whether the farmers receive any subsidies to manage the manure. The Moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Harald Menzi [Harald.Menzi@shl.bfh.ch] One of the major risks of spreading pathogens from livestock production units (irrespective of size and intensity) to humans or other animals is through surface or ground water. If manure is discharged to water courses, if it is lost to water courses through run-off or leakage or if there are leaching and drainage losses from manure facilities, the water is contaminated. If this contaminated water is used as drinking water, for washing etc., the pathogens are transmitted to humans and animals. IT SHOULD THEREFORE BE AN URGENT PRIORITY, NOT ONLY FROM THE ENVIRONMENTAL POINT OF VIEW, BUT ALSO FROM THE HYGIENIC POINT OF VIEW, TO PREVENT ANY POLLUTION OF SURFACE AND GROUND WATER. The pollution risk can be reduced through manure treatment. Nevertheless, most treatments can not give absolute guaranty that the effluent poses no health risk, especially if the treatment facility is defective, is not running properly or does not have the appropriate capacity. In Switzerland and in Europe in general, the transmission of pathogens through animal excreta and manure is a topic of minor importance, in spite of the fact that, except for anaerobic storage, manure treatment is seldom practised. I believe that this is primarily due to the fact that manure discharge to water courses are strictly prohibited and direct manure losses to surface and ground water are heavily penalised. Even the discharge of highly purified effluent from manure treatment facilities is prohibited to minimise the pollution risk. To control serious health and environmental risks from manure management I think the following steps are essential: * Collect and store the manure for some time in facilities that prevent run-off and leaching * Spread the manure on agriculture land, taking care that eatable products are not polluted (no application for x weeks before harvest, not on vegetables and other crops that are eaten raw and unpealed etc.) * Take all measures to minimise losses from the field by matching the time and dose of application to the nutrient need of the crops, equilibrium of the nutrient balance etc. Manure treatment can give added security but is not essential if the above steps are implemented. Special care is necessary for manure used as feed. Harald Menzi Swiss College of Agriculture From: Rosales, Mauricio (AGAL) Sent: 13 July 2001 16:11 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Bob Orskov on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Bob Orskov brings up an important issue in the use of growth promotants and antibiotics in animal feed and the residues in manure which may be poisonous when ingested by other animals. These products are frequently used where animal health has been compromised by a high incidence of pathogens. Where government regulations strictly control the use of these products farmers have had to be more aware of the importance of ensuring animal health through good housing and husbandry to prevent or control disease and promote efficient production and performance. This has not always necessarily been a voluntary process but the result of strictly enforced regulations and education in the use of these products. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Bob Orskov [b.orskov@mluri.sari.ac.uk] Dear Colleagues, I have made comments before about this topic which is also refereed to in the discussions from Yucatan. That is the problems imposed by industrial intensive animal production systems of including in diet for pigs and poultry growth promoters which makes the manure poisonous for other animals and indeed for soils as well. I refer here to copper additions to pig diet and arsenic and other antibiotic compounds in poultry diets. To me these practices should at least be discouraged. In my opinion they should be universally banned. It is environmental crimes. I have seen many sheep die from eating pastures manured by pig excreta containing 1000ppm copper on a dry matter basis and fish die when it used to fertilize fish ponds. I have seen poultry manure in brazil used to cattle and creating problems. Here the poultry producers give the farmers the chicks and the feed and collect the finished broilers and leave the farmers with the excreta. Soils in Holland is left with excess copper levels. I think from this conference dealing with AWI we could perhaps make a strong appeal to governments to make such practices illegal as soon as possible. It is motivated only by profit because the polluter does not pay. I would like to have some opinions to see if other colleagues think the same as I do on the topic, Best regards BoB Orskov Aberdeen Professor E R Orskov ( OBE) Macaulay land Use Research Institute Craigiebuckler Aberdeen AB158QH Scotland UK Phone direct 01224 498243. Institute 01224 318611 Fax 01224 311556 Web pages Http://www.mluri.sari.ac.uk/ifru From: Rosales, Mauricio (AGAL) Sent: 14 July 2001 08:56 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Wolfgang Bayer on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Wolfgang Bayer responds to the comment of the moderators. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Wolfgang Bayer [Email: wb.waters@link-goe.de] When we compare disease risks of small scale farmers and large industrialized enterprises we should not forget the type of animals used - especially if we look at developing countries. Generally local animals, kept by smallholder are tolerant or resistant to a range of diseases who can cause havoc among large enterprises, which normally have animals which are uniform, can produce more under favourable conditions, but are also more susceptible to various diseases. The uniformity of the animals also increases the risk a rapid spreading of a disease. As far as I know, people who have close contacts with animals develop immunity/premunity to some diseases which can be transmitted from animals to people. If no longer exposed to disease pressure these defence mechanism will be weakened. As large, intensive farms normally employ fewer people per 100 head of livestock than do small farms the conclusion is that potentially the disease risk from large holdings are greater than from many small farms, if no precautionary measures are taken. Wolfgang Bayer ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Comments from the moderators We agree that prolonged exposure to certain pathogens transmitted from animals to humans can build up a degree of immunity, however we don't understand his reasoning for saying that exposure of fewer people to larger numbers of animals results in greater risk to transmission of disease. It may be helpful if he could clarify his reasoning. Further it is an interesting remark from Dr. Bayer regarding the risk that smallholders pose to large producers. We are not sure whether he is attributing the difference in susceptibility between animals kept by different producers to the difference in the health programs and management styles. If that is the case, we agree with him. There is enough evidence in the literature that favours an all-in-all- out management system in comparison to multiage. We are not sure we agree with him that the "uniformity of the animals," which we interpreted as all-in-all-out, "increases the risk of spread of disease. Several factors influence the risk of spread of disease and not solely the uniformity of the animals. We agree that the output from concentrated animal operations has a higher contributory risk to the public health and the environment than from smallholders. However, and as eluted to by Dr. Bayer, there is a more man-animal contact in smallholder system than in concentrated animal operations. In other words, large operations are more likely to affect the environment and hence put the public at risk while smallholders are likely to have a kind of occupational hazard. Therefore, under an AWI program the different systems have different considerations. The moderators From: Rosales, Mauricio (AGAL) Sent: 17 July 2001 11:53 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Wolfgang Bayer on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Wolfgang Bayers argues that large livestock enterprises e.g. pigs and poultry lack genetic diversity compared with small farm systems. He claims a higher genetic diversity increases the animal populations ability to withstand stress and disease and survive. The moderators agree that this is most likely true simply due to survival over time of the animals with the ability to develop resistance to diseases. However the problem in large livestock enterprises in our opinion overcomes this by reducing the risk of introducing pathogens at the outset, and maintaining their health through increasing sanitation, vaccinations etc. Marker Assisted Selection (MAS) in pigs is now being used to speed up the selection of genetic lines of animals that are resistant to diseases e.g. E. coli K88, Salmonella and to stress factors. To produce large volumes of food this more scientific approach has to be considered. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Wolfgang Bayer Sorry for being not clear. With uniformity of animals in large enterprises I mean genetic uniformity (chicken or pigs produced by commercial breeding companies are very uniform - and although different lines are maintained or can be rapidly established - the genetic diversity of modern breeds is low compared to smallholder systems - especially in developing countries - where natural reproduction takes place and because of many mothers and fathers and a very limited number of offspring per parent, genetic diversity is high. Although I am aware that indigenous breeds are not resistant to all diseases (e.g. rinderpest can cause a high mortality among indigenous African cattle) a higher genetic diversity increases the probability that some animals can cope with the new stress/disease and will survive. By the way a breed which potentially can suffer greatly from the decrease of genetic diversity are the Holstein Friesian cattle. Apparently 30 % of the bulls used in artificial insemination are offspring of 1 bull and the millions of HF-cows in the US represent an estimated 50 genotypes. The decrease of biodiversity has admittedly little to do with manure management, but much to do with the difference between smallholders and large farms and the different breeding practices. Hope that this clarifies the points Wolfgang Bayer From: Rosales, Mauricio (AGAL) Sent: 17 July 2001 14:38 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Robert McCroskey on Health Sessi on ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Robert McCroskey endorses the comments of Dr Orskov regarding chemical compounds such copper, arsenic and antibiotics etc. that persist in the manure. He discusses the need for some control over these compounds citing the use of copper in rabbits' diets. He correctly states that in some countries the use of heavy metals, antibiotics, hormones is banned. We support his concerns, and further suggest that in many countries these compounds have strict withholding periods, are regularly monitored for as residues in meat, milk, soils and waterways; also a schedule system to ensure only qualified persons are able to prescribe and dispense many of these products is commonplace. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Robert McCroskey [bobmc@uniserve.com] Dear Participants, I would like to agree with Prof. Dr. Orskov of Aberdeen on the topic of banning chemotherapy, the use of chemical compounds such as copper sulphate, arsenic and antibiotics which persist in the manure after excretion by the production animal. As previously mentioned, here we use the rabbit manure directly on the sheep pastures, so the high levels of copper found in normal use in rabbit feeds in North America cannot be used; our copper is held to the level of the animal's requirement in the feed, a supplementary 15 ppm (15 mg/kg). As well, nitrogen and phosphorus levels are minimized while potassium can be adjusted to meet the requirements of the pasture, to assist in preventing lodging, within the limits that potassium is a growth inhibitor in rabbits. The high levels of copper in rabbit feed began in North America after success with copper feeding in pigs, and continues despite the fact that copper feeding is most effective in hotter climates, and despite the fact that the USDA objects to the high levels of copper in rabbit livers and will set limits on organ heavy metal content if such use continues. Some "developed" countries have already banned or are considering banning heavy metal chemotherapy (and antibiotic and hormone use) in livestock on the grounds that it creates an increasing residue in soils. This is another indication that we cannot consider any by-product to be "waste" that is just put out of sight; we are in a closed system here on "Spaceship Earth" and there are consequences to all actions. So-called "developing" countries should not expect to have their "kick-at-the-can" as regards certain pollutants (such as ozone destroying refrigerants, DDT, agrochemicals, etc.); they should realize that perhaps this step in human "progress" is best to skip over, particularly since many parts of the world are short of water which works to dilute such pollutants. Robert McCroskey Canadian Centre for Rabbit Production Development (NGO) Surrey, BC, Canada From: Rosales, Mauricio (AGAL) Sent: 18 July 2001 13:50 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Reginald De Deken on Health Sessi on ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dr De Deken's concerns about people continuing to advocate the use of manure as a feed source are well taken. We agree that in the light of recent food related diseases that have had catastrophic consequences for both humans (BSE) and animals (FMD) health in Europe, where surveillance and control measures can be implemented and afforded, developing countries must take great care in the disposal of manure of effluent to ensure public health. This disease outbreaks have also highlighted the importance of the need for further research to give us better understanding of their etiology, epidemiology and mode of transmission when developing AWI in developing countries. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Reginald De Deken [rdeken@itg.be] I understand that the disposal of manure constitutes an important problem for the livestock breeder, who want to get rid of this manure at little or no cost. However, I do not understand that there are still people advocating the use of manure as a source of feed, especially not if this manure is used to feed closely related animals. Haven't we learn enough lessons from the enormous problems we encountered recently with food related diseases, e.g. bovine spongiform encephalopathia, dioxin and foot and mouth disease? Industrialised countries can afford the expenses related to the surveillance, control and eradication of these diseases, but third world countries can not and therefore will have to very careful not to endanger public health. Dr. R. De Deken Institute of Tropical Medicine Nationalestraat 155, B-2000 Antwerp Belgium From: Rosales, Mauricio (AGAL) Sent: 18 July 2001 13:59 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Manuel Sanchez on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Manuel Sanchez [Manuel.Sanchez@fao.org] From the contributions and discussion on health related aspects and nutrient management it is clear that one of the main conclusions from this conference will be that of "no discharge" of liquid fractions of manure treatments into water courses or bodies. For the participants from industrialized countries where legislation and enforcement are well established, this might seem logical. But it is no so obvious in the developing countries where it is still allowed to discharge treated or partially treated effluents that meet certain chemical parameters. Arthur Muehling, an Agricultural Engineer from the University of Illinois, told me about 10 years ago, that it was not economically viable to treat the effluents from livestock operations so as to discharge them into streams and rivers. These need to be recycled into the farm for washing or for crops. I am sure that is the simple fact is accepted by authorities, livestock experts and farmers from developing countries, the situation will change and measures will be taken to reduce the volume because it will not be possible to dump the excess nutrients into the environment, at least into the liquid water. The problem of emissions will be more difficult to resolve. But lets take one step at the time. "No discharge" would already be a great step forward. M. Sanchez From: Rosales, Mauricio (AGAL) Sent: 19 July 2001 09:03 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L:Comments from Brian Hedley on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Brian Hedley states that the lower level of transmission amongst smallholder held animals is due to stall feeding and low level contact between animals. He also correctly states that this is more evident in extensive pastoral animals. If he means transmission of diseases from animal to animal this is absolutely true especially when compared to large-scale intensive animal production. However as stated in the introductory paper on animal and human health, for large scale intensive animal production to be successful in maintaining animal health the system must start with animals free of highly contagious pathogenic organisms, be maintained as such with strict biosecurity and adopt all-in-all-out systems of management. If we want to produce large quantities of high quality food efficiently this is the price we have to pay. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Brian Hedley [hedleybr@xtra.co.nz] Perhaps a reason for a lower level of transmission amongst smallholder held animals is that smallholders in intensive farming situations adopt stall feeding and the level of contact between animals is low, and even in more extensive pastoral farming situations the herds are small and dispersion during the day at least reduces animal to animal contact. Brian Hedley From: Rosales, Mauricio (AGAL) Sent: 19 July 2001 14:26 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Fernando Madalena on Health Sessi on ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dr Madalena has a valid point in reply to Wolfgang Bayer regarding the importance of having a balanced approach to animal breeding when propagating a 'good' genetic trait in large numbers of animals e.g. resistance to a disease. He indicates the importance of maintaining genetic diversity or at least ensuring the preservation of other important genetic characteristics in animal breeding. The moderators ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Fernando E. Madalena [Fermadal@dedalus.lcc.ufmg.br] Re: genetic variation in disease resistance. Farmers will try to use as good germplasm as they may, in any country, developed or not. "Good" is what gives them more economic return (although modified by propaganda). Given the elaborate agriculture organization in developed countries, specifically large scale companies commanding breeding decisions affecting millions of animals, the "good" genotypes come to be widespread, and that is a good thing. There is nothing wrong in all animals being uniformly good. (Would somebody complain because almost all zebus are tick resistant?) Also, parasite/disease resistance are just some of the many traits that influence economic performance, so they have to be appropriately weighted in selection decisions against the other traits (animal breeders have the techniques for doing that). However, by reproducing the best germplasm variation is lost, so there is a conflict between short term economic gains and long term gains, including changes in the environment/markets. One just can't have one's cake and eat it. So we may go slowly, select less intensely to preserve some variation (a currently very active research field) or we may preserve the cake ingredients, the genetic variation, to reconstitute it or make other cakes if necessary. Of course somebody will have to pay the cost of preservation, but that's another story. Fernando E. Madalena Departamento de Zootecnia Escola de Veterinária Universidade Federal de Minas Gerais Department of Animal Sciences School of Veterinary Sciences Federal University of Minas Gerais Postal address: Cx.P. 567, 30123-970 Belo Horizonte-MG, Brazil Phone: 55-31-3499-2180 Fax: 55-31-3499-2168 From: Rosales, Mauricio (AGAL) Sent: 19 July 2001 16:30 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Manuel Sanchez on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Manuel Sanchez comments on De Deken's concerns on advocating the use of manure as a feed resource. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From Manuel Sanchez [manuel.sanchez@fao.org] Nature is full of examples where the excreta of one species is the feed for another. Several of our domestic species practice coprophagy, including rabbits and pigs. In Europe the use of manure as feed is prohibited, but in the USA and many other countries, excreta is used as feed, particularly across species. For example, chicken litter and poultry droppings are commonly used as feed ingredients in feed-lot cattle or as supplements for cattle in the range. Swine excreta is also used to feed cattle. The issue here is that ideally these valuable resources need to be properly treated to prevent the dissemination of any pathogens. Biogas effluent is an excellent feed and nutrient source for fish ponds. Swine excreta ensiled with other feedstuffs gives good results as a ration for fattening beef cattle. BSE had nothing to do with feeding manure, but contaminated meat and bone meal; dioxin accumulation occurs when given feed contaminated from industrial emissions and incinerators; foot- and-mouth disease is transmitted through various ways but mainly through air and direct animal-to-animal contact. Yes, these serious diseases have caused alarm among consumers and politicians, and need to be controlled and prevented, but we should not regulate the use of resources unless there is a real risk for animal and human health. Generalisations on banning certain feedstuffs are conservative but often very expensive solutions. Manuel Sanchez From: Nell, A.J. [A.J.Nell@IAC.agro.nl] Sent: 20 July 2001 10:58 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: Closing of the Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dear Participants, The session on Animal and Human Health in relation to Area-Wide Integration has produced much interesting information and exchange of opinions. It remains a very complicated and often controversial topic and and I have no doubt that the discussion on this topic will continue in this forum and during the workshop in Bangkok. However, it is now time to close this session even if many of the questions posed in the introductory paper still remain unanswered. Ranald Cameron, one of the session moderators, has prepared a summary of the contributions which will be put on the list shortly after this message. Even though we now officially close this session participants can continue to send messages on this topic, especially on the sofar unanswered questions from the introductory paper. Summaries of these messages will be send to the list from time to time and the full text will be available at the E-conference website. I wish to thank the participants for their contributions to this session and the moderators for preparing the introductory paper, for guiding the discussion and commenting on the contributions and Ranald Cameron for the preparation of the summary paper. I look forward to receiving more contributions on the Health topic and on the other ongoing sessions on Zoning and Social Aspects. Kind regards Arend Jan Nell Conference Moderator From: Rosales, Mauricio (AGAL) Sent: 20 July 2001 11:11 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L:Summary of the Discussion on Animal and Human He alth Issues In AWI ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Summary of Animal and Human Health Issues In AWI. The moderators have prepared a summary of the discussions on animal and human health in relation to AWI. The conference offered an excellent forum to discuss the challenges to AWI. The contributions made stimulated considerable and valuable dialogue and discussion. The pool of participants in the conference included government officials, agricultural and academic educators, and industry personnel. Most of the concerns were with the risk from water and food- borne pathogens to animal, human, and the environment. The concerns were with pathogens from intensive or concentrated animal operations contaminating watersheds and water supply systems and soil used for producing freshly consumed crops such as fruit and vegetables. The participants alluded to several manure management practices that have the potential to reduce the risk of these pathogens. A number of the participants strongly advocated enforcement of the current regulations and/or implementation of new ones on the use and treatment of manure and effluent before it is spread on pastures, transported or finds its way into surface or underground water supplies. The intent is to manage the risk from these pathogens. Besides contamination by pathogens, there was also considerable concern for the hazard of pollution with heavy metals, chemicals and antibiotics fed to animals finding their way into the environment and posing risk to both human and animal health. Only a few participants addressed the problems (if any) of the likely source of pathogens i.e. in the animals on the farm. A number of the responses suggested that establishing and maintaining animals free of specific pathogens e.g. bacteria, protozoa and other parasites was not feasible in developing countries in an AWI program. The discussions highlighted the gaps in knowledge regarding the impact of AWI on environmental quality and public health. Concentrated animal feeding operations (CAFOs) and agricultural operations have been identified as potential point sources of and contributors to non-point source pollution. In times of shrinking resources, cost-effective management strategies depend on accurate identification of the source(s) of the pathogen and the pathway by which pollutes the environment. Such plans can only be developed through an integrated and valid research, education, and extension approach. Armed with such knowledge, we can develop a risk assessment approach, correctly identify source(s) of hazards in AWI, understand the factors that contribute to their presence and perpetuation on CAOFs, develop a comprehensive risk model, identify cost-effective best management practices, and implement a prolific agricultural environmental management plan. The following are summaries of individual participant's comments in the chronological order in which they were published: * In relation to management of effluent the animals should be considered first and foremost. Optimum digestion is essential and can be related to breed, nutrition and the presence of pathogens. * Taxing products from intensive livestock farms in peri-urban areas should be essential. Encourage the development of intensive livestock farms in urban areas where land is still available and maintenance costs are manageable. This would facilitate goods and produce movement to urban areas and manure towards the rural areas. Ensure regulations that safeguard the environment. Although small farms will not entirely solve the problem of the great demand for food they should be part of the solution. The internet should be used for dissemination of technological knowledge on waste management, recycling and pollution control. * One contributor claims to have developed a process which can solve the problems of pollution associated with effluent from medium to large scale intensive animal production systems. The process destroys bacterial pathogens, removes malodour, provides water suitable for recycling, and produced bacterial pathogen free sludge for use as a soil conditioner and fertiliser. * Solving the problems of pollution from manure is a financial problem. The economic costs of recovering from a biological catastrophe (outbreak of disease in humans or animals) would be greater than its prevention. There are inherent dangers in feeding manure to livestock and the complete elimination of pathogens from manure is only possible by multi-chamber anaerobic-aerobic biodigesters or by acidogenic fermentation. * Laws regarding manure in several States in the US relate to pathogen pollution. The amount of pollution a lake or river can sustain is related to the maintenance of fish-life and suitability of drinking water (total maximum daily load). Some States limit manure application on soils, other efforts focus on dietary change in the animals to reduce levels of phosphorous and other nutrients in manure e.g. supplementing feeds with phytase and other enzymes, amino acid feeding and reformulation of diets with lower micronutrients. Vegetable production in California and demands for manure compost has raised concerns of adequate pathogen kill when used for fruit and vegetables. * The importance of highly contagious and pathogenic diseases such as Swine fever, FMD and Aujezsky's disease should not be overlooked. The spread of these diseases has been promoted by the transport of manure, slurry and waste water. Many of these diseases are notifiable but continue to be endemic in many areas. * Zoonotic pathogens e.g. salmonella, leptospirosis, cryptosporidium, E. coli etc. occur at a high incidence in many areas. Pig manure and waste water are potential sources of these pathogens and contaminate crops, washing water, drinking water, slaughter houses and uncooked food. * Of great concern is the emergence of new zoonotic diseases e.g. Nipah virus, Japanese encephalitis and Influenza in SE Asia. There is a need for more research and understanding of these diseases including the role of manure and waste water from farms in their transmission. There is a need for a good monitoring system for these diseases, and appropriate animal and meat inspection protocols developed that are internationally recognised. * No such thing as disease free animals or disease free production exists. However specific pathogen free animals or minimal disease animals can be produced, but it is not realistic to raise livestock in sterile sealed chambers to prevent transmission of pathogens to the environment. Reducing the number of micro-organisms can have problematic side effects e.g. allowing competitive micro-organisms to flourish. Conversely reduction of pathogens such as salmonella and E. coli in poultry can be achieved by competitive exclusion. * It was pointed out that pollution around water holes for animal drinking in Sahel resulted in diarrhoea in humans, and that local people are not aware of the link between manure around watering points and their health problems. * In India it has been shown that the construction of biogas plants and latrines promoted as an environmentally friendly method of disposing of both cattle and human manure has resulted in improvement in sanitation and health of rural householders. * In relation to the issue of eliminating pathogens from manure, the problem arises only when slurry is applied to vegetables for fresh human consumption. Conversely when manure is applied to crops cultivated for feed, industrial or energy processes there is no need for the elimination of pathogens. Also for the cultivation of cereals such as wheat for human consumption there is not a problem in application of manure if it is carried out months in advance of harvest. * Besides bacteria in manure, protozoa in water such as cryptosporidium parvum and guiardia species are important. There is a need for valid research to provide data on the perceived risk and proper dissemination of information. The challenge is how to consolidate the research efforts in times of shrinking resources and diverse political interests to promote AWI. A surveillance system is an excellent tool to implement cost effective intervention strategies to reduce the risk from pathogens. * Problems imposed by industrial intensive animal production systems include the use of growth promoters e.g. copper in pig diets, and arsenic in pig and poultry diets. These can contaminate pastures and be a risk to the health of other animals e.g. grazing animals, or in water, fish. Governments should make the use of these products illegal. * It has been stated that copper, as a pro-oxidant has the potential to cause oxidative injury to micro-organisms in manure and hence kill them. The final decision on using these compounds in animal feeds and in AWI program should be based on cost effectiveness of the choice of the smallholders, and the cost/benefit ratio for large scale operations. * Several participants argued against encouraging the use of specific pathogen free animals in an AWI program. The argument was that the approach should be to try to minimise the risk of introducing pathogens, amplification of these organisms on the farm and control of the daily maximum load on manure. This can be done by identifying and implementing cost effective intervention strategies. The decision to implement has to have a scientific basis and cost justification. * The dangers of pollution of both surface and underground waters with pathogens from manure and the risk to human health when the water is used for drinking or washing was highlighted by one participant. However this is considered of minor importance in Switzerland due to the fact that both prohibition and heavy penalties exist for allowing drainage into water courses. * It was argued that large scale enterprises such as pigs or poultry lack genetic diversity compared with small farm systems. Higher genetic diversity increases the animal population's ability to withstand stresses, diseases and survive. * Farmers will try to use the best genetic material that they have access to in both developed and developing countries, because this is what gives a better economic return. Large scale breeding companies can make decisions affecting millions of animals with good genotypes and this is a good thing. There is nothing wrong in all animals being uniformly good (like most zebras being tick resistant). Disease resistance is just one of the many traits that influence economic performance and has to be appropriately weighted in selection decisions against other important traits. Animal breeders have the technique for doing this. By reproducing the best genes, variation or diversity may be lost, however there are ways of preserving the variation by selecting less intensively and at the same time preserving important genetic traits, currently a very active research field. * One participant cannot understand that there are still people advocating the use of manure as a source of feed especially for feeding closely related animals. He argues that we should have learnt our lesson from the enormous problems recently encountered with food related diseases e.g. BSE, dioxin and FMD. Although industrial countries may be able to afford to control or eradicate these diseases, third world countries cannot, and therefore should be very careful about endangering public health. The Moderators Ranald Cameron Hussni Mohammed From: Rosales, Mauricio (AGAL) Sent: 23 July 2001 18:09 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L:Comments from Cheryl McCrindle on Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I agree with Prof. McCrinndle, it is not necessarily that the risk of contamination of the environment from small animal operations (smallholders) is negligible. As pointed out in his response, several factors play a role in contribution to the environmental and public health risk in a AWI. These factors have to be taken into consideration before a valid statement about the potential risk can be made. Farm biosecurity and management practices play a major role in the introduction to and perpetuation of pathogens on farms, which in turn influence the risk to the environment. The challenge is how to help the smallholders in an AWI program without burdening them financially. Hussni O. Mohammed Session Moderator ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Prof C McCrindle [mccrindl@op1.up.ac.za] Reply to Brian Hendly's point that smallhlder systems have less potential for transmission of disease: It is well known that there is a positive co-relation between animal density and transmission of disease. It is also well known that there is a high animal density in intensive systems. However the corollary is not true - in other words it does not follow that there is a low animal density in smallholder and pastoral systems. 1. Smallholder systems may be urban and very close to each other. 2. Animals are not neccessarily confined and often left to forage for themselves. 3. Pastoral systems are herd systems and usually very large herds are run together. As a result there are pandemics where very large numbers of animals are affected in the developing world and many diseases which have been eliminated from intensive systems still smoulder eg ringworm in camels and in cattle rinderpest, east coast fever, anthrax, rabies, in goats: brucellosis, in pigs african swine fever, foot and mouth etc. Best wishes Prof Cheryl McCrindle South Africa From: Rosales, Mauricio (AGAL) Sent: 24 July 2001 12:05 To: 'LEAD-AWI-ECONF-L@mailserv.fao.org' Subject: LEAD-AWI-ECONF-L: Comments from Landers, Wagner and Buckley on Sa nchez Contribution On the Health Session ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ELECTRONIC CONFERENCE ON AREA WIDE INTEGRATION OF CROP AND LIVESTOCK PRODUCTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We have received some reactions to Manuel Sanchez comments on the use of manure as a feed resource. Mel Landers, Hans Gerhard Wagner Hans and Katherine Buckley remind us of the risks involved and the consumer's perceptions of similar practices. I would like to close this particular discussion on feeding manure as it is not under the actual discussion agenda. Further comments on the issue of feeding manure will not be send to the list. The Moderator ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Mel Landers [agrimel@yahoo.com] Manuel Sanchez states in his most recent post that, "we should not regulate the use of resources unless there is a real risk for animal and human health." Continual exposure to a new species greatly increases the risk that a genetic mutation will occur which will allow an organism to use the new species as an alternate host. The last century saw the development of scores of new diseases in humans. This same process occurs in animals in the wild and in livestock species. This process is what has enabled parasitic species to survive when one the population of its major host declines as a result of environmental changes, over hunting or due to their hosts inability to compete with species which have been newly introduced into their habitat. Often drastic measures are taken to reduce the risk of passing organisms from one individual to another within a species. But, there is no regard for protecting one species from the diseases of another when manure is used as feed. When the risk of devastation to livestock populations is taken into consideration, it does not make much sense to continue this practice, especially when consideration is given to the immense need for meat to feed a quickly growing population. It would appear that the examples which Mr. Sanchez criticizes were meant as examples of the devastation which are possible when a pathogen "jumps" species. The risks are real and should not be dealt with in a cavalier manner. We are talking about the wellbeing of people who do not have the resources to easily pick up and start over again when things go wrong. As to the fact that the practice is employed in the US, it should be noted that there is much better sanitation in feeding operations in the US than is feasible in most developing countries. also, the US is not always the most enlightened country when it comes to the best management practices. Profit is usually considered to be the most important factor to consider and using manure as feed is a profitable practice when that manure was produced in a sanitary facility. In a conversation I had earlier this week with a state veterinarian here in the US, I was informed that there is presently an effort underway to end the practice in this country due to the inherent risks. Sincerely Melvin Landers agrimel@yahoo.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From: Hans Gerhard Wagner.[wagner@fao.org] I tend to agree with Manuel Sanchez but not everything which is technically feasible is also acceptable to the consumer who sits at the end of the food chain. Truly we often do not know what we eat and how it has been produced but in these last years consumer behaviour is changing considerable. I remember years ago a plan to feed the 'soup' of a rendering plant directly to pigs avoiding the high energy costs for drying. It would have been safe because properly treated but consumer perception stopped the plan. Regards Hans - Gerhard Wagner Regional Animal Production and Health Officer FAO Reg. Office for Asia and the Pacific ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Katherine Buckley [KBuckley@EM.AGR.CA] I am totally against feeding manure in any form - there are just too many uncertainties. We have not isolated all of the organisms that are potential vectors of disease because there is no methodology for growing these things out and fingerprinting them yet. Kathy