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Characterization of backyard poultry production systems and disease risk in the central zone of Chile
Research in Veterinary Science 93 (2012) 121–124
Contents lists available at ScienceDirect
Research in Veterinary Science journal homepage: www.elsevier.com/locate/rvsc
Characterization of backyard poultry production systems and disease risk in the central zone of Chile C. Hamilton-West a,⇑, H. Rojas b, J. Pinto c, J. Orozco a, L.P. Hervé-Claude d, S. Urcelay a a
Department of Preventive Veterinary Medicine, Faculty of Veterinary Science, University of Chile, Santiago, Chile CERES, Biosecurity and Food Quality Services, Santiago, Chile c Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases/Global Early Warning and Response System for Major Animal Diseases, Including Zoonoses (EMPRES/GLEWS), Animal Health Service, Food and Agriculture Organization of the United Nations, Rome, Italy d Department of Biometry, Epidemiology and Information Processing, WHO-Collaborating Centre for Research and Training in Veterinary Public Health, University of Veterinary Medicine, Hannover, Germany b
a r t i c l e
i n f o
Article history: Received 12 July 2010 Accepted 11 June 2011
Keywords: Backyard production Poultry Disease risk Biosecurity Avian Influenza Newcastle disease
a b s t r a c t Backyard poultry production systems (BPS) are an important and widespread form of poultry production. There is a common perception that biosecurity standards in BPS are generally poor and BPS are usually associated with animal diseases and zoonoses. In this study BPS were identified in the vicinity of six wetlands, having these a higher risk of presenting and introducing avian diseases such as HPAI and Newcastle disease, as defined by the national veterinary services, in to Chile’s main poultry production area. BPS were characterized through a field questionnaire and the main areas covered by the survey were BPS structure, biosecurity and value chain. The BPS identified in this study share most characteristics on biosecurity, poultry management and product commercialization, but it was possible to identify a certain degree of variation within and among the study sites. BPS in Chile are similar to those in other regions, with a relatively small flock size (average 37 birds), a low level of biosecurity measures and lack of poultry disease management. Management findings include that most farmers used mixed/partial confinement, with low or no biosecurity and disease control measures in place. Eggs were the main output and were used mainly for home consumption or sale at local markets. Sick birds’ treatment with drugs approved for other species or for human use could represent a risk to human health, owing to the possible presence of drug residues in poultry products. Despite the different structures of the poultry sector worldwide, BPS can play a major role in disease maintenance and spread because its management conditions characteristics and the lack of animal health services adapted to these production systems. This should be an alert message to the veterinary authorities to improve coverage of veterinary assistance and surveillance activities in backyard poultry production. Ó 2011 Elsevier Ltd. All rights reserved.
Backyard poultry production is the most widespread form of poultry keeping in the world (FAO-OIE-WorldBank, 2008), being an important component of small farmers’ livelihoods and a tool for poverty alleviation (Dolberg, 2007; Sonaiya, 2007). Birds are kept in a low input/low output system, with the available scavenging feed base supplemented with food scraps and grains. Birds and their by-products are usually consumed by their owners, sold locally and used as gifts (FAO, 2005; FAO-OIE-WorldBank, 2008). The issues described represent favorable conditions that make BPS more susceptible to receiving and spreading infectious
⇑ Corresponding author. Address: Department of Preventive Veterinary Medicine, Faculty of Veterinary Science, University of Chile, Santiago, Av. Santa Rosa 11735, La Pintana, Chile. Tel.: +56 2 978 5578; fax: +56 2 978 5659. E-mail address: [email protected] (C. Hamilton-West). 0034-5288/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.rvsc.2011.06.015
diseases such as HPAI and Newcastle disease (FAO-OIE-WorldBank, 2008), since they represent the interface where interaction between domestic backyard birds and wild birds occurs (Henning et al., in press). Furthermore, the majority of backyard poultry households do not apply basic hygiene and biosecurity measures, with a potential risk posed by animal diseases to humans. Sick birds may be handled, sold, slaughtered and consumed without considering that the infections that made the chicken sick may also potentially be harmful to man (Iqbal, 2009). The Chilean poultry sector had improved its production and standards by the early 1990s, covering all internal demand and including exports of poultry products (APA-ASOHUEVO, 2006). This development relies on Chilean sanitary situation, where major avian diseases are absent. The last outbreak of a major avian disease in Chile occurred in 2002, when H7N3 HPAI affected two poultry farms in Valparaiso region. This event was successfully eradicated by the
122
C. Hamilton-West et al. / Research in Veterinary Science 93 (2012) 121–124
coordinated action between public and private sectors (Rojas and Moreira, 2006). Poultry production in Chile is highly integrated at both geographical and industrial level. For the poultry meat sub-sector there are only seven companies/industries covering the full market value chain (MVC), and operating with high biosecurity standards. Approximately 95% of poultry meat production is located in the central zone of Chile, including the regions of Valparaiso, Libertador General Bernardo O’Higgins (LGB O’Higgins) and Metropolitan. For the poultry layer sub-sector, there are 173 companies/industries involved, with over 75% located in the central zone of Chile (APA-ASOHUEVO, 2006). This broad geographical zone can, therefore, be considered as Chile’s main poultry production area (MPPA). As opposed to the meat sub-sector, farm size within the poultry layer sub-sector is diverse, and not all farms incorporate the full MVC. It is also possible to find differences in biosecurity levels. BPS within the MPPA were estimated at 14,179 units and the population of backyard birds at 418,809 (Hamilton-West et al., 2007, 2009). However, there is no information available on the characteristics of this poultry sub-sector. The aim of this study is to collect information to characterize the poultry flock structure, biosecurity conditions and market value chain of BPS present in the Chilean MPPA. Six study sites were selected within Chile’s MPPA, since were considered as priority risk zones avian disease introduction by the official veterinary service (SAG, 2006). The sites are mainly coastal wetlands where migratory birds arrive every year and share their habitat with local wild birds (Tala, 2006). Study sites spatial distribution is presented in Fig. 1. All of the BPS were identified within a radius of at least 5 km from each wetland centroid or 3 km from its borders. Information regarding BPS structure, biosecurity and MVC was gathered by semi-structured interviews with smallholders. The interviews were performed between December 2007 and June 2008, by trained veterinary medicine students of the University of Chile. Descriptive statistics were provided to characterize the BPS, taking into consideration structure, biosecurity and trade relation-
La Ligua
Aconcagua - Mantagua Batuco
Maipo El Yali
Topocalma
Fig. 1. Main Chilean poultry production areas (MPPA) and study sites for characterization of backyard poultry production systems (BPS) during 2007–2008.
ships. Comparisons between categories of quantitative variables were made by analysis of variance tests and for categorical variables, significant differences were calculated at 5% error using the Chi-square test (Dohoo et al., 2010). One hundred and seventy-five BPS were identified and all of them were surveyed, representing the total BPS in the proximity of the six study sites. The sites where it was possible to identify a greater proportion of BPS were ‘Aconcagua-Mantagua’ and ‘El Yali’ wetlands, together representing 64% of the BPS. The average BPS size was 37.4 birds (SD = 32.8), taking into account all the different species. There were no statistical differences between the number of birds bred in BPS belonging to different study sites (P = 0.33). The highest flock sizes were found in ‘‘Batuco’’ and ‘‘Aconcagua-Mantagua’’ areas, with an average of 52.3 and 40.7 birds, respectively. Most of the BPS owners declared that the number of birds on their premises was constant throughout the year (63.4%), followed by those who identified an increase in the bird population in spring–summer (32.6%) or in autumn–winter (4%). Eighteen percent of BPS bred more than one bird species, including turkeys, ducks and geese. The most common species was domestic chickens present in 93% of the BPS. Wild birds, such as Turdus falcklandii, Molothrus bonariensis, Curaeus curaeus and Diuca diuca, were kept as pets in some BPS (3%). Women managed the 68% of the BPS, men 18%, and in the remaining 14% the responsibilities were shared between men and women. All BPS had external fences and three types of bird confinement were identified: (a) permanent confinement, (b) free-range (no confinement), and (c) mixed confinement, with birds kept free-range during the day and in pens at night. The differences found in the proportion of those confinement strategies were significant (P < 0.01), where mixed confinement was the prevailing system (Table 1). In most of the BPS (97.7%) it was possible to identify that visitors could come into contact with backyard birds and that there were no disinfection procedures employed prior to entering or before leaving a farm. In BPS where visitors had no contact with birds, it was because birds were kept in permanent confinement; although also on those farms there were no entry or exit disinfection measures in place. No BPS farmers had any formal training in disease recognition. Their knowledge was based purely on experience and shared knowledge among neighbors. In most BPS (72%), no health management of any type was performed and no treatment of sick birds or preventive procedures were applied. However, in the group practicing health management, 71.4% had had some sort of medical advice from veterinarians or veterinary technicians, without knowing in detail the type of treatment being performed. The remaining 28.6% treated birds with the use of medicinal plants and drugs registered for other animal species, including drugs intended for human use. To manage mortalities at farm level (Table 1), the most common option was to dispose of carcasses off the farm (39%), followed by burning/burial of dead birds (35%). To a lesser extent, it was recognized that the carcasses were disposed of directly in the neighboring wetland area, a practice only reported on the ‘‘AconcaguaMantagua’’ site. Official surveillance activities for detection of exotic diseases such as HPAI and Newcastle disease, performed by veterinary services personnel, were carried out in the 20% of the BPS identified. Most BPS bred poultry as a ‘family tradition’, with more than 20 years of tenure (75%), while a lesser number of BPS had had poultry for a period ranging from 2 to 5 years, or less than 2 years (Table 1). The most common production objectives were: (i) household home-consumption; and (ii) household home-consumption and sale, representing together 97% of the BPS. The target markets for those farms which sold products were mostly neighbors/tourists. Just a few BPS (8%) sold their products to local markets
C. Hamilton-West et al. / Research in Veterinary Science 93 (2012) 121–124 Table 1 Categories for confinement conditions, mortality management, years of breeding poultry and target market of backyard production systems identified at each study site, within the Chilean main poultry production area during 2007–2008. Variable
Categories
Confinement
Free range Permanent Mixed
66 18 91
37.7 10.3 52.0
Mortality management
Dispose of away from farm
68
38.9
Bury Burn Refuse/disposed as trash Dispose of in wetland area
51 10 41 5
29.1 5.7 23.4 2.9
131
74.9
Between 5 and 20 Between 2 and 5 Less than 2
0 29 15
0.0 16.6 8.6
Tourists Neighbors Local markets Household homeconsumption Pets/gifts (did not sell)
8 73 14 75
4.6 41.7 8.0 42.9
5
2.8
Years breeding poultry
Target market
More than 20
Number
Percentage
(Table 1). The main product identified was eggs and the secondary products were poultry meat (64%) and live birds (36%). As replacement or to increase the number of poultry owned, the strategy most used was breeding birds within the flock (68%), while the rest of the BPS add birds by purchasing them from neighbors, local rural markets, and commercial farms or through government support projects. When new birds arrived on a farm, none of the BPS initiated any quarantine procedures and there were no concerns regarding either the health of the new birds or the state of the farms they had come from. Backyard poultry rearing in many rural communities is a centuries-old, traditional livelihood. The identified BPS size in the Chilean MPPA is similar to the BPS flock size described in Viet Nam (Hong Hanh et al., 2007), and higher than the reported in Ethiopia and South Africa (Aklilu et al., 2008; Herve-Claude et al., 2009). In most Chilean BPS, chickens prevailed over ducks and geese. This is important considering that the latter group of birds can be associated with a higher risk for diseases such as HPAI, since they can form a potential reservoir or permanent source of infection. For instance, in Thailand a higher risk of H5N1 HPAI epidemics in areas with abundance of free grazing ducks was demonstrated (Gilbert et al., 2006, 2007). Free range or mixed confinement, coupled with poor biosecurity measures, are conditions that increase the opportunity for contacts between poultry of different flocks and between domestic and wild birds. These conditions are common in Chilean BPS and in other countries, such as Viet Nam and Thailand or Ethiopia and South Africa (Gilbert et al., 2007; Hong Hanh et al., 2007; Aklilu et al., 2008; Iqbal, 2009; Herve-Claude, 2010). A study in the Eastern Cape, South Africa, identified that 83% of BPS used freeranging and mixed confinement, while only 6% used permanent confinement of poultry (Herve-Claude, 2010). Practices such as lack of control of visitors and direct contact with backyard poultry increase the risk of introduction of pathogens or infectious agents. Buying new poultry to increase flock size without quarantine measures could represent another evident risk factor for disease introduction and spread. It was recognized, in this study, that sick and dead backyard birds were not consumed or sold in Chilean BPS, thus reducing the threat to human health, and differing from the global conditions described for backyard poultry where sick birds may be slaughtered and consumed (Iqbal, 2009). Another finding related
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to mortality management was that the main issue for households was to remove dead birds from the farm, even disposing of them in the wetland areas, a practice which could represent a source of infection for backyard poultry and for wild birds (Awan et al., 1994). Additionally, it was recognized that in some BPS, sick birds were generally treated without the supervision of veterinarians or veterinary technicians, using drugs approved for other species or for human use. This could represent a risk to human health, owing to the possible presence of drug residues in poultry products (Greenlees, 2003). Inputs to maintain BPS in Chile’s MPPA can be considered low, based on available scavenging feed base supplemented with food scraps and grains, as described in other regions (FAO-OIE-WorldBank, 2008). Breeding activities are performed by women, as described for Ethiopian BPS (Aklilu et al., 2008). The income produced by backyard poultry can be considered low, since most of the households wait for an opportunity to sell their products to neighbors or tourists that pass by the farm and few of them try to sell their products at local markets. This is different to the situation described for some Asian countries (Lesnoff et al., 2009) where backyard poultry can be an important source of income since traditional poultry command better prices than commercial chickens. Moreover, backyard poultry has been identified as an important source of food for owners and their families (Hong Hanh et al., 2007; Iqbal, 2009). Despite the different structures of the poultry sector worldwide, BPS can play a major role in disease maintenance and spread because its management conditions (Hong Hanh et al., 2007; Cecchi et al., 2008; Iqbal, 2009) and the lack of animal health services adapted to these production systems. This should be an alert message to the veterinary authorities to improve coverage of veterinary assistance and surveillance activities in backyard poultry, a situation that was highlighted in the Chilean surveillance plan for HPAI, Newcastle disease and other exotic avian diseases (SAG, 2006). Contrastingly, by the time of the study, only a low proportion of BPS (20%) recognized as having been visited by veterinary officers. The BPS identified in this study share most characteristics on biosecurity, poultry management and product commercialization, but it was possible to identify a certain degree of variation within and among the study sites. Those variations could be used to estimate differences in the risk of introduction and spread of poultry diseases, which may facilitate prioritization of surveillance activities, the setting-up of preventive measures and the elaboration of contingency plans. Conflict of Interest Statement The authors claim no conflict of interest. Role of the funding source The authors claim no role by the funding source. Acknowledgments We thank Dr. Francisca Araya and for her assistance on the field work and Dr. Sherrilyn Wainwright for early reviews and helpful suggestions. This study was partially funded by the Asociación de Productores Avícolas de Chile A.G. References Aklilu, H.A., Udo, H.M.J., Almekinders, C.J.M., Van der Zijpp, A.J., 2008. How resource poor households value and access poultry: village poultry keeping in Tigray, Ethiopia. Agricultural Systems 96, 175–183.
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APA-ASOHUEVO, 2006. Caracterización de la industria avícola nacional. Boletín Veterinario Oficial. Servicio Agrícola y Ganadero 6, 1–8. Awan, M.A., Otte, M.J., James, A.D., 1994. The epidemiology of Newcastle disease in rural poultry: a review. Avian Pathology 23, 405–423. Cecchi, G., Ilemobade, A., Le Brune, Y., Hogerwerf, L., Slingenbergh, J., 2008. Agroecological features of the introduction and spread of the highly pathogenic avian influenza (HPAI) H5N1 in northern Nigeria. Geospatial Health 3, 7–16. Dohoo, I., Martin, W., Stryhn, H., 2010. Veterinary Epidemiologic Research. AVC Inc., University of Prince Edward Island, Charlottetown. Dolberg, F., 2007. Poultry production for livelihood improvement and poverty alleviation. In: Thieme, O., Pilling, D. (Eds.), Poultry in the 21st Century. Avian Influenza and Beyond, Bangkok, p. 81. FAO, 2005. A Global Strategy for the Progressive Control of Higly Pathogenic Avian Influenza (HPAI). Food and Agriculture Organization of the United Nations, Rome, Italy, p. 85. FAO-OIE-WorldBank, 2008. Biosecurity for Highly Pathogenic Avian Influenza. Issues and Options 73. Gilbert, M., Chaitaweesub, P., Parakamawongsa, T., Premashthira, S., Tiensin, T., Kalpravidh, W., Wagner, H., Slingenbergh, J., 2006. Free-grazing ducks and highly pathogenic avian influenza, Thailand. Emerging Infectious Diseases 12, 227234. Gilbert, M., Xiao, X., Chaitaweesub, P., Kalpravidh, W., Premashthira, S., Boles, S., Slingenbergh, J., 2007. Avian influenza, domestic ducks and rice agriculture in Thailand. Agriculture, Ecosystems and Environment 119, 409–415. Greenlees, K.J., 2003. Animal drug human food safety toxicology and antimicrobial resistance – the square peg. International Journal of Toxicology 22, 131–134. Hamilton-West, C., Rojas, H., Urcelay, S., 2007. Backyard production systems spatial characterization, the first step to assess the risk level for the introduction and spread of highly pathogenic avian influenza in the main Chilean poultry production areas. In: GISVET 07, Copenhagen, Denmark. Hamilton-West, C., Rojas, H., Pinto, J., Orozco, J., Urcelay, S., 2009. Characterization of backyard poultry productions systems in the vicinity of high risk areas for HPAI introduction. In: Proceedings of the 12th Symposium of the International
Society for Veterinary Epidemiology and Economics, vol. 12. ISVEE, Durban, South Africa, p. 760. Henning, J., Henning, K.A., Morton, J.M., Long, N.T., Ha, N.T., Vu, L.T., Vu, P.P., Hoa, D.M., Meers, J., in press. Highly pathogenic avian influenza (H5N1) in ducks and in-contact chickens in backyard and smallholder commercial duck farms in Viet Nam. Preventive Veterinary Medicine. Corrected Proof. Herve-Claude, L.P., 2010. Evaluation of Strategies on a Farm Animal Census in the Eastern Cape Province, South Africa. Institute of Biometry, Epidemiology and Information Processing. University of Veterinary Medicine of Hannover, Hannover, p. 152. Herve-Claude, L.P., Lwanga-Iga, I., Kroll-Lwanga-Iga, S., Nyangiwe, N., Nkubungu, Y., Majavu, N., Matshoba, T., Kreienbrock, L., 2009. The Eastern Cape Animal Information System Amathole: animal population structures in two Eastern Cape communal wards. In: Proceedings of the 12th Symposium of the International Society for Veterinary Epidemiology and Economics, vol. 12. ISVEE, Durban, South Africa, p. 595. Hong Hanh, P.T., Burgos, S., Roland-Holst, D., 2007. The Poultry Sector in Viet Nam: Prospects for Smallholder Producers in the Aftermath of the HPAI Crisis. Food and Agriculture Organization of the United Nations, Rome, Italy, p. 14. Iqbal, M., 2009. Controlling avian influenza infections: the challenge of the backyard poultry. Journal of Molecular and Genetic Medicine 3, 119–120. Lesnoff, M., Peyre, M., Duarte, P.C., Renard, J.-F., Mariner, J.C., 2009. A simple model for simulating immunity rate dynamics in a tropical free-range poultry population after avian influenza vaccination. Epidemiology and Infection 137, 1405–1413. Rojas, H., Moreira, R., 2006. Influenza aviar en Chile: una sinopsis. Servicio Agrícola y Ganadero, Santiago, Chile. SAG, 2006. In: Ganadero, S.A.Y. (Ed.), Proyecto nacional de vigilancia epidemiológica en enfermedades aviares exóticas de la lista a de la OIE y en bronquitis infecciosa renal 2004–2007. Chile, p. 6. Sonaiya, F., 2007. Smallholder family poultry as a tool initiate rural development. In: Thieme, O., Pilling, D. (Eds.), Poultry in the 21st Century. Avian Influenza and Beyond, Bangkok, p. 81. Tala, C., 2006. Qué hacen aquí esas gaviotas. . .qué hacen aquí, tan lejos de su lugar natal. Boletín Veterinario Oficial. Servicio Agrícola y Ganadero 5, 1–24.
Contents lists available at ScienceDirect
Research in Veterinary Science journal homepage: www.elsevier.com/locate/rvsc
Characterization of backyard poultry production systems and disease risk in the central zone of Chile C. Hamilton-West a,⇑, H. Rojas b, J. Pinto c, J. Orozco a, L.P. Hervé-Claude d, S. Urcelay a a
Department of Preventive Veterinary Medicine, Faculty of Veterinary Science, University of Chile, Santiago, Chile CERES, Biosecurity and Food Quality Services, Santiago, Chile c Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases/Global Early Warning and Response System for Major Animal Diseases, Including Zoonoses (EMPRES/GLEWS), Animal Health Service, Food and Agriculture Organization of the United Nations, Rome, Italy d Department of Biometry, Epidemiology and Information Processing, WHO-Collaborating Centre for Research and Training in Veterinary Public Health, University of Veterinary Medicine, Hannover, Germany b
a r t i c l e
i n f o
Article history: Received 12 July 2010 Accepted 11 June 2011
Keywords: Backyard production Poultry Disease risk Biosecurity Avian Influenza Newcastle disease
a b s t r a c t Backyard poultry production systems (BPS) are an important and widespread form of poultry production. There is a common perception that biosecurity standards in BPS are generally poor and BPS are usually associated with animal diseases and zoonoses. In this study BPS were identified in the vicinity of six wetlands, having these a higher risk of presenting and introducing avian diseases such as HPAI and Newcastle disease, as defined by the national veterinary services, in to Chile’s main poultry production area. BPS were characterized through a field questionnaire and the main areas covered by the survey were BPS structure, biosecurity and value chain. The BPS identified in this study share most characteristics on biosecurity, poultry management and product commercialization, but it was possible to identify a certain degree of variation within and among the study sites. BPS in Chile are similar to those in other regions, with a relatively small flock size (average 37 birds), a low level of biosecurity measures and lack of poultry disease management. Management findings include that most farmers used mixed/partial confinement, with low or no biosecurity and disease control measures in place. Eggs were the main output and were used mainly for home consumption or sale at local markets. Sick birds’ treatment with drugs approved for other species or for human use could represent a risk to human health, owing to the possible presence of drug residues in poultry products. Despite the different structures of the poultry sector worldwide, BPS can play a major role in disease maintenance and spread because its management conditions characteristics and the lack of animal health services adapted to these production systems. This should be an alert message to the veterinary authorities to improve coverage of veterinary assistance and surveillance activities in backyard poultry production. Ó 2011 Elsevier Ltd. All rights reserved.
Backyard poultry production is the most widespread form of poultry keeping in the world (FAO-OIE-WorldBank, 2008), being an important component of small farmers’ livelihoods and a tool for poverty alleviation (Dolberg, 2007; Sonaiya, 2007). Birds are kept in a low input/low output system, with the available scavenging feed base supplemented with food scraps and grains. Birds and their by-products are usually consumed by their owners, sold locally and used as gifts (FAO, 2005; FAO-OIE-WorldBank, 2008). The issues described represent favorable conditions that make BPS more susceptible to receiving and spreading infectious
⇑ Corresponding author. Address: Department of Preventive Veterinary Medicine, Faculty of Veterinary Science, University of Chile, Santiago, Av. Santa Rosa 11735, La Pintana, Chile. Tel.: +56 2 978 5578; fax: +56 2 978 5659. E-mail address: [email protected] (C. Hamilton-West). 0034-5288/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.rvsc.2011.06.015
diseases such as HPAI and Newcastle disease (FAO-OIE-WorldBank, 2008), since they represent the interface where interaction between domestic backyard birds and wild birds occurs (Henning et al., in press). Furthermore, the majority of backyard poultry households do not apply basic hygiene and biosecurity measures, with a potential risk posed by animal diseases to humans. Sick birds may be handled, sold, slaughtered and consumed without considering that the infections that made the chicken sick may also potentially be harmful to man (Iqbal, 2009). The Chilean poultry sector had improved its production and standards by the early 1990s, covering all internal demand and including exports of poultry products (APA-ASOHUEVO, 2006). This development relies on Chilean sanitary situation, where major avian diseases are absent. The last outbreak of a major avian disease in Chile occurred in 2002, when H7N3 HPAI affected two poultry farms in Valparaiso region. This event was successfully eradicated by the
122
C. Hamilton-West et al. / Research in Veterinary Science 93 (2012) 121–124
coordinated action between public and private sectors (Rojas and Moreira, 2006). Poultry production in Chile is highly integrated at both geographical and industrial level. For the poultry meat sub-sector there are only seven companies/industries covering the full market value chain (MVC), and operating with high biosecurity standards. Approximately 95% of poultry meat production is located in the central zone of Chile, including the regions of Valparaiso, Libertador General Bernardo O’Higgins (LGB O’Higgins) and Metropolitan. For the poultry layer sub-sector, there are 173 companies/industries involved, with over 75% located in the central zone of Chile (APA-ASOHUEVO, 2006). This broad geographical zone can, therefore, be considered as Chile’s main poultry production area (MPPA). As opposed to the meat sub-sector, farm size within the poultry layer sub-sector is diverse, and not all farms incorporate the full MVC. It is also possible to find differences in biosecurity levels. BPS within the MPPA were estimated at 14,179 units and the population of backyard birds at 418,809 (Hamilton-West et al., 2007, 2009). However, there is no information available on the characteristics of this poultry sub-sector. The aim of this study is to collect information to characterize the poultry flock structure, biosecurity conditions and market value chain of BPS present in the Chilean MPPA. Six study sites were selected within Chile’s MPPA, since were considered as priority risk zones avian disease introduction by the official veterinary service (SAG, 2006). The sites are mainly coastal wetlands where migratory birds arrive every year and share their habitat with local wild birds (Tala, 2006). Study sites spatial distribution is presented in Fig. 1. All of the BPS were identified within a radius of at least 5 km from each wetland centroid or 3 km from its borders. Information regarding BPS structure, biosecurity and MVC was gathered by semi-structured interviews with smallholders. The interviews were performed between December 2007 and June 2008, by trained veterinary medicine students of the University of Chile. Descriptive statistics were provided to characterize the BPS, taking into consideration structure, biosecurity and trade relation-
La Ligua
Aconcagua - Mantagua Batuco
Maipo El Yali
Topocalma
Fig. 1. Main Chilean poultry production areas (MPPA) and study sites for characterization of backyard poultry production systems (BPS) during 2007–2008.
ships. Comparisons between categories of quantitative variables were made by analysis of variance tests and for categorical variables, significant differences were calculated at 5% error using the Chi-square test (Dohoo et al., 2010). One hundred and seventy-five BPS were identified and all of them were surveyed, representing the total BPS in the proximity of the six study sites. The sites where it was possible to identify a greater proportion of BPS were ‘Aconcagua-Mantagua’ and ‘El Yali’ wetlands, together representing 64% of the BPS. The average BPS size was 37.4 birds (SD = 32.8), taking into account all the different species. There were no statistical differences between the number of birds bred in BPS belonging to different study sites (P = 0.33). The highest flock sizes were found in ‘‘Batuco’’ and ‘‘Aconcagua-Mantagua’’ areas, with an average of 52.3 and 40.7 birds, respectively. Most of the BPS owners declared that the number of birds on their premises was constant throughout the year (63.4%), followed by those who identified an increase in the bird population in spring–summer (32.6%) or in autumn–winter (4%). Eighteen percent of BPS bred more than one bird species, including turkeys, ducks and geese. The most common species was domestic chickens present in 93% of the BPS. Wild birds, such as Turdus falcklandii, Molothrus bonariensis, Curaeus curaeus and Diuca diuca, were kept as pets in some BPS (3%). Women managed the 68% of the BPS, men 18%, and in the remaining 14% the responsibilities were shared between men and women. All BPS had external fences and three types of bird confinement were identified: (a) permanent confinement, (b) free-range (no confinement), and (c) mixed confinement, with birds kept free-range during the day and in pens at night. The differences found in the proportion of those confinement strategies were significant (P < 0.01), where mixed confinement was the prevailing system (Table 1). In most of the BPS (97.7%) it was possible to identify that visitors could come into contact with backyard birds and that there were no disinfection procedures employed prior to entering or before leaving a farm. In BPS where visitors had no contact with birds, it was because birds were kept in permanent confinement; although also on those farms there were no entry or exit disinfection measures in place. No BPS farmers had any formal training in disease recognition. Their knowledge was based purely on experience and shared knowledge among neighbors. In most BPS (72%), no health management of any type was performed and no treatment of sick birds or preventive procedures were applied. However, in the group practicing health management, 71.4% had had some sort of medical advice from veterinarians or veterinary technicians, without knowing in detail the type of treatment being performed. The remaining 28.6% treated birds with the use of medicinal plants and drugs registered for other animal species, including drugs intended for human use. To manage mortalities at farm level (Table 1), the most common option was to dispose of carcasses off the farm (39%), followed by burning/burial of dead birds (35%). To a lesser extent, it was recognized that the carcasses were disposed of directly in the neighboring wetland area, a practice only reported on the ‘‘AconcaguaMantagua’’ site. Official surveillance activities for detection of exotic diseases such as HPAI and Newcastle disease, performed by veterinary services personnel, were carried out in the 20% of the BPS identified. Most BPS bred poultry as a ‘family tradition’, with more than 20 years of tenure (75%), while a lesser number of BPS had had poultry for a period ranging from 2 to 5 years, or less than 2 years (Table 1). The most common production objectives were: (i) household home-consumption; and (ii) household home-consumption and sale, representing together 97% of the BPS. The target markets for those farms which sold products were mostly neighbors/tourists. Just a few BPS (8%) sold their products to local markets
C. Hamilton-West et al. / Research in Veterinary Science 93 (2012) 121–124 Table 1 Categories for confinement conditions, mortality management, years of breeding poultry and target market of backyard production systems identified at each study site, within the Chilean main poultry production area during 2007–2008. Variable
Categories
Confinement
Free range Permanent Mixed
66 18 91
37.7 10.3 52.0
Mortality management
Dispose of away from farm
68
38.9
Bury Burn Refuse/disposed as trash Dispose of in wetland area
51 10 41 5
29.1 5.7 23.4 2.9
131
74.9
Between 5 and 20 Between 2 and 5 Less than 2
0 29 15
0.0 16.6 8.6
Tourists Neighbors Local markets Household homeconsumption Pets/gifts (did not sell)
8 73 14 75
4.6 41.7 8.0 42.9
5
2.8
Years breeding poultry
Target market
More than 20
Number
Percentage
(Table 1). The main product identified was eggs and the secondary products were poultry meat (64%) and live birds (36%). As replacement or to increase the number of poultry owned, the strategy most used was breeding birds within the flock (68%), while the rest of the BPS add birds by purchasing them from neighbors, local rural markets, and commercial farms or through government support projects. When new birds arrived on a farm, none of the BPS initiated any quarantine procedures and there were no concerns regarding either the health of the new birds or the state of the farms they had come from. Backyard poultry rearing in many rural communities is a centuries-old, traditional livelihood. The identified BPS size in the Chilean MPPA is similar to the BPS flock size described in Viet Nam (Hong Hanh et al., 2007), and higher than the reported in Ethiopia and South Africa (Aklilu et al., 2008; Herve-Claude et al., 2009). In most Chilean BPS, chickens prevailed over ducks and geese. This is important considering that the latter group of birds can be associated with a higher risk for diseases such as HPAI, since they can form a potential reservoir or permanent source of infection. For instance, in Thailand a higher risk of H5N1 HPAI epidemics in areas with abundance of free grazing ducks was demonstrated (Gilbert et al., 2006, 2007). Free range or mixed confinement, coupled with poor biosecurity measures, are conditions that increase the opportunity for contacts between poultry of different flocks and between domestic and wild birds. These conditions are common in Chilean BPS and in other countries, such as Viet Nam and Thailand or Ethiopia and South Africa (Gilbert et al., 2007; Hong Hanh et al., 2007; Aklilu et al., 2008; Iqbal, 2009; Herve-Claude, 2010). A study in the Eastern Cape, South Africa, identified that 83% of BPS used freeranging and mixed confinement, while only 6% used permanent confinement of poultry (Herve-Claude, 2010). Practices such as lack of control of visitors and direct contact with backyard poultry increase the risk of introduction of pathogens or infectious agents. Buying new poultry to increase flock size without quarantine measures could represent another evident risk factor for disease introduction and spread. It was recognized, in this study, that sick and dead backyard birds were not consumed or sold in Chilean BPS, thus reducing the threat to human health, and differing from the global conditions described for backyard poultry where sick birds may be slaughtered and consumed (Iqbal, 2009). Another finding related
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to mortality management was that the main issue for households was to remove dead birds from the farm, even disposing of them in the wetland areas, a practice which could represent a source of infection for backyard poultry and for wild birds (Awan et al., 1994). Additionally, it was recognized that in some BPS, sick birds were generally treated without the supervision of veterinarians or veterinary technicians, using drugs approved for other species or for human use. This could represent a risk to human health, owing to the possible presence of drug residues in poultry products (Greenlees, 2003). Inputs to maintain BPS in Chile’s MPPA can be considered low, based on available scavenging feed base supplemented with food scraps and grains, as described in other regions (FAO-OIE-WorldBank, 2008). Breeding activities are performed by women, as described for Ethiopian BPS (Aklilu et al., 2008). The income produced by backyard poultry can be considered low, since most of the households wait for an opportunity to sell their products to neighbors or tourists that pass by the farm and few of them try to sell their products at local markets. This is different to the situation described for some Asian countries (Lesnoff et al., 2009) where backyard poultry can be an important source of income since traditional poultry command better prices than commercial chickens. Moreover, backyard poultry has been identified as an important source of food for owners and their families (Hong Hanh et al., 2007; Iqbal, 2009). Despite the different structures of the poultry sector worldwide, BPS can play a major role in disease maintenance and spread because its management conditions (Hong Hanh et al., 2007; Cecchi et al., 2008; Iqbal, 2009) and the lack of animal health services adapted to these production systems. This should be an alert message to the veterinary authorities to improve coverage of veterinary assistance and surveillance activities in backyard poultry, a situation that was highlighted in the Chilean surveillance plan for HPAI, Newcastle disease and other exotic avian diseases (SAG, 2006). Contrastingly, by the time of the study, only a low proportion of BPS (20%) recognized as having been visited by veterinary officers. The BPS identified in this study share most characteristics on biosecurity, poultry management and product commercialization, but it was possible to identify a certain degree of variation within and among the study sites. Those variations could be used to estimate differences in the risk of introduction and spread of poultry diseases, which may facilitate prioritization of surveillance activities, the setting-up of preventive measures and the elaboration of contingency plans. Conflict of Interest Statement The authors claim no conflict of interest. Role of the funding source The authors claim no role by the funding source. Acknowledgments We thank Dr. Francisca Araya and for her assistance on the field work and Dr. Sherrilyn Wainwright for early reviews and helpful suggestions. This study was partially funded by the Asociación de Productores Avícolas de Chile A.G. References Aklilu, H.A., Udo, H.M.J., Almekinders, C.J.M., Van der Zijpp, A.J., 2008. How resource poor households value and access poultry: village poultry keeping in Tigray, Ethiopia. Agricultural Systems 96, 175–183.
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