Backyard Farms Research Articles

Evaluation of the risk of classical swine fever (CSF) spread from backyard pigs to other domestic pigs by using the spatial stochastic disease spread model Be-FAST: The example of Bulgaria

The study presented here is one of the very first aimed at exploring the potential spread of classical swine fever (CSF) from backyard pigs to other domestic pigs. Specifically, we used a spatial stochastic spread model, called Be-FAST, to evaluate the potential spread of CSF virus (CSFV) in Bulgaria, which holds a large number of backyards (96% of the total number of pig farms) and is one of the very few countries for which backyard pigs and farm counts are available. The model revealed that, despite backyard pigs being very likely to become infected, infections from backyard pigs to other domestic pigs were rare. In general, the magnitude and duration of the CSF simulated epidemics were small, with a median [95% PI] number of infected farms per epidemic of 1 [1,4] and a median [95% PI] duration of the epidemic of 44 [17,101] days. CSFV transmission occurs primarily (81.16%) due to indirect contacts (i.e. vehicles, people and local spread) whereas detection of infected premises was mainly (69%) associated with the observation of clinical signs on farm rather than with implementation of tracing or zoning. Methods and results of this study may support the implementation of risk-based strategies more cost-effectively to prevent, control and, ultimately, eradicate CSF from Bulgaria. The model may also be easily adapted to other countries in which the backyard system is predominant. It can also be used to simulate other similar diseases such as African swine fever.

Survey of Trichinella infections in domestic pigs from northern and eastern Henan, China

The aim of this work was to investigate the current situation of Trichinella infections in swine in the cities of Anyang and Shanqiu in the Henan province historically designated as trichinellosis-free. A total of 475 diaphragm muscle samples were collected from 2010 to 2011 and examined by trichinelloscopy and artificial digestion. No Trichinella larvae were detected by trichinelloscopy; however, using the digestion method, 3.79% (18/475) of domestic pigs were deemed positive for Trichinella. Among the 475 pigs examined, 112 from an industrialized pig farm were negative. However. Trichinella larvae were detected in 10% (9/90) of pigs from small pig farms, which was significantly higher than the 3.3% (9/273) of pigs found positive from backyard farms (P<0.05). The larval burdens in infected animals ranged from 0.1 to 1.58 larvae per gram. The larvae were identified by multiplex PCR as Trichinella spiralis. Our study confirms the existence of porcine trichinellosis in northern and eastern parts of Henan. The results will be useful for evaluating the risk of infection for humans. Given this new found data, public health officials should consider implementing strategies to eliminate human transmission.

Which way for UPA in Africa?

This paper reviews a synthesis, made in late 2010, which identified the major issues arising from the East and Central African data as: the relationship of UPA to food security and poverty; whether it recycles waste effectively; and what was happening in terms of policy response. The paper updates the analysis and examines it in relation to issues raised by data from Southern Africa. The capacity of UPA to recycle nutrients, especially on the highly efficient crop–livestock backyard farms, signifies its potential role in making cities sustainable. Investigating the reasons for positive policy environments in some places, or the vested interests that mitigate against support for urban farming—especially by the poor—in other places, suggests that emerging farmers' networks or institutions that support them need to engage with larger political processes in order to take advantage of a potentially productive economic sector.

Study of poultry coccidiosis in organized and backyard farms of Jammu region

Aim: The present study was undertaken to know the Prevalence of chicken coccidiosis in Jammu division in both organized and backyard chickens during the year 2010-11. Materials and Methods: A total of 720 faecal samples were collected from both organized farms and backyard poultry (unorganized) sector of Jammu. Results: The overall prevalence of 39.58% was recorded in the present study and five Eimeria species were identified viz., E. tenella, E. necatrix, E. maxima, E. acervulina and E. mitis. E. tenella was the predominant species in both organized and unorganized farms. Conclusion: Higher prevalence of 53.61% in unorganized (backyard poultry birds) as compared to organized birds (25.55%) was recorded. The prevalence was the highest in monsoon from both organized and unorganized managemental practices.

Trends Intherapeutic and Prevention Strategies for Management of Bovine Mastitis: An Overview

Mastitis is one of the most economically significant diseases for the dairy industry for backyard farmers in developing countries and high producing herds worldwide. Two of the major factors impeding reduction in the incidence of this disease is [a] the lack of availability of an effective vaccine capable of protecting against multiple etiological agents and [b] propensity of some of the etiological agents to develop persistent antibiotic resistance in biofilms. This is further complicated by the continuing revolving shift in the predominant etiological agents of mastitis, depending upon a multitude of factors such as variability in hygienic practices on farms, easy access leading to overuse of appropriate or inappropriate antibiotics at suboptimal concentrations, particularly in developing countries, and lack of compliance with the recommended treatment schedules. Regardless, Staphylococcus aureus and Streptococcus uberis followed by Escherichia coli, Streptococcus agalactiae has become the predominant etiological agents of bovine mastitis followed Streptococcus agalactiae, Streptococcus dysagalactiae, Klebsiella pneumonia and the newly emerging Mycoplasma bovis. Current approaches being pursued to reduce the negative economic impact of this disease are through early diagnosis of infection, immediate treatment with an antibiotic found to either inhibit or kill the pathogen(s) in vitro using planktonic cultures and the use of the currently marketed vaccines regardless of their demonstrated effectiveness. Given the limitations of breeding programs, including genetic selection to improve resistance against infectious diseases including mastitis, it is imperative to have the availability of an effective broad-spectrum, preferably cross-protective, vaccine capable of protecting against bovine mastitis for reduction in the incidence of bovine mastitis, as well as interrupting the potential cross-species transmission to humans. This overview highlights the major etiological agents, factors affecting susceptibility to mastitis, and the current status of antibiotic-based therapies and prototype vaccine candidates or commercially available vaccines against bovine mastitis as potential preventative strategies. © 2013 Tiwari JG, et al.

Prevalence and some risk factors associated with trichinellosis in backyard pig farms in Zaria, Nigeria

The aim of this study was to determine the presence of trichinellosis in backyard-farmed pigs and the risk factors associated with the infection in Zaria, Kaduna State. Serum samples were collected from 120 pigs selected at random from 50 small backyard farms, and the presence of Trichinella spp. antibodies was determined using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. Data on farm management practices from the farms were obtained through the use of a structured questionnaire. The overall seroprevalence of Trichinella spp.-specific antibodies was 40 % (48/120) by ELISA. All the extensive farms sampled had at least one Trichinella-positive animal. The age and sex of the animals were not significantly (p>0.05) associated with the infection; however, the management systems, presence of rodents, rodent control, and access to dead pigs showed significant (p<0.05) association with Trichinella spp.-infected pigs on the farm. In conclusion, there was a high prevalence of antibodies to trichinellosis in backyard raised pigs in Zaria, and intensive pig farming with the adoption of proper biosecurity measures is advocated to prevent the transmission and spread of trichinellosis.

The evolution of productivity performance on China’s dairy farms in the new millennium

China’s dairy farm structure has experienced fundamental changes across farm types. As the number of backyard farms has dramatically declined, the share of dairy cows from backyard farms has decreased by 22.4% from 2003 to 2008. However, the herd numbers of larger dairy farms have increased. In particular, the share of dairy cows has risen by 18.8% on small farms, by 22.2% on medium farms, and by 80.8% on large farms over the same period. Total factor productivity was decomposed into technical efficiency and technological change on China’s dairy farms using the stochastic production frontier framework. The estimated results indicate that patterns of productivity growth appear to have shifted in the 2000s compared with the 1990s, from generally driven by technological change to exclusively driven by technological change on backyard and small farms and uniquely driven by the improvement of technical efficiency on large farms. Tests of the econometric assumption indicate that the variations in total factor productivity growth patterns across farm types and regions are likely caused by the feed input biases and cropping production practice.

Productivity, efficiency and structural problems in Chinese dairy farms

PurposeThe purpose of this paper is to identify the structural problem in the Chinese dairy sector. There exists a large number of low‐efficiency, small‐scale farms, and productivity inequality between small and large farms keeps increasing, which is a possible driving force behind the Melamine scandal in 2008.Design/methodology/approachUsing the stochastic frontier production function, this paper estimates and compares the changes in technology and technical efficiency between backyard, small‐scale, medium‐scale and large‐scale dairy farms in China over the period between 2004 and 2008.FindingsThere are compensating effects between technology and technical efficiency. However, low yield for backyard farms is mainly caused by traditional low‐yield varieties, even though the technical efficiency is very high, which cannot compensate for the low technology.Research limitations/implicationsThe author put the assumption of constant return to scale mainly due to the data availability. Such an assumption implies that there are no scale‐effects between the different scales in productivity, and the productivity difference is explained by technology and technical efficiency.Practical implicationsIn order to solve the structural problems, Chinese governments should help small‐scale farmers to adopt new high‐yield varieties, to subsidize small‐scale farmers, and to train farmers to master the complicated skills for raising high‐yield varieties.Originality/valueThe paper gives another possible explanation for the Melamine scandal of milk powder in 2008. If the structural problem cannot be solved, similar food safety scandals could happen once again.

Checking into China's cow hotels: Have policies following the milk scandal changed the structure of the dairy sector?

China's milk scandal is well known for causing the nation's largest food safety crisis and for its effect on thousands of children. Less, however, is known about the effect on the other victim: China's small dairy farmers. Although small backyard producers were not the ones that added melamine to the milk supply, the incomes of dairy farmers fell sharply after the crisis. In response, one of the actions taken by the government was to encourage small dairy producers to check into production complexes that were supposed to supply services, new technologies, and provide for easy/bulk procurement of the milk produced by the cows of the farmers. Because both farmers and their cows were living (and working) away from home, in the rest of the paper we call these complexes cow hotels. In this paper we examine the dynamics of China's dairy production structure before and after the milk scandal. In particular, we seek to gain a better understanding about how China's policies have been successful in encouraging farmers to move from the backyard into cow hotels. We also seek to find if larger or smaller farmers respond differently to these policy measures. Using data from a sample of farmers from dairy-producing villages in Greater Beijing, our empirical analysis finds that 1 yr after the milk scandal, the dairy production structure changed substantially. Approximately one quarter (26%) of the sample checked into cow hotels after the milk scandal, increasing from 2% before the crisis. Our results also demonstrate that the increase in cow hotel production can largely be attributed to China's dairy policies. Finally, our results suggest that the effects of government policy differ across farm sizes; China's dairy policies are more likely to persuade larger farms to join cow hotels. Apparently, larger farms benefit more when they join cow hotels. Overall, these results suggest that during the first year after the crisis, the government policies were effective in moving some of the backyard farmers into cow hotels (although 60% farmers remained backyard producing).

Optimizing early detection of avian influenza H5N1 in backyard and free-range poultry production systems in Thailand

For infectious diseases such as highly pathogenic avian influenza caused by the H5N1 virus (A/H5N1 HP), early warning system is essential. Evaluating the sensitivity of surveillance is a necessary step in ensuring an efficient and sustainable system. Stochastic scenario tree modeling was used here to assess the sensitivity of the A/H5N1 HP surveillance system in backyard and free-grazing duck farms in Thailand. The whole surveillance system for disease detection was modeled with all components and the sensitivity of each component and of the overall system was estimated. Scenarios were tested according to selection of high-risk areas, inclusion of components and sampling procedure, were tested. Nationwide passive surveillance (SSC1) and risk-based clinical X-ray (SSC2) showed a similar sensitivity level, with a median sensitivity ratio of 0.96 (95% CI 0.40–15.00). They both provide higher sensitivity than the X-ray laboratory component (SSC3). With the current surveillance design, the sensitivity of detection of the overall surveillance system when the three components are implemented, was equal to 100% for a farm level prevalence of 0.05% and 82% (95% CI 71–89%) for a level of infection of 3 farms. Findings from this study illustrate the usefulness of scenario-tree modeling to document freedom from diseases in developing countries.

Mortality rate and clinical features of highly pathogenic avian influenza in naturally infected chickens in Bengladesh

A retrospective study was performed to assess the mortality rates and clinical signs in commercial and backyard chickens naturally infected with the highly pathogenic avian influenza (HPAI) H5N1 virus in Bangladesh. All of the 33 commercial and 25 backyard farms, recorded during the first wave of HPAI outbreaks (January to November 2007) in Bangladesh, were enrolled in this study. The farm profile data, stock information and major clinical signs recognised by the farmers and/or farm attendants, were collected through a prototype questionnaire. The investigating veterinarians' retrospective appraisals of the clinical signs were recorded by interview. After the clinical onset, the incidence rates of mortality in breeder, commercial broiler, commercial layer and backyard chickens were, respectively: 0.0215, 0.0341, 0.0179 and 0.0703 per chicken-day at risk. The four major clinical signs observed were cyanotic combs and wattles, oedema of the head and face, drowsiness and huddling and ecchymotic discoloration of the leg shanks. The first sign (cyanotic combs and wattles) was equally observed in chickens from commercial and backyard farms (p = 0.44) but the second (oedema of the head and face) was more common in backyard farms (p = 0.03).

Virulent Newcastle disease virus in Nigeria: identification of a new clade of sub-lineage 5f from livebird markets

Newcastle disease (ND), caused by Avian Paramyxovirus Type 1, is a highly contagious and devastating viral disease of poultry of worldwide distribution with an enormous economic impact. Although ND is reported to be endemic in Nigeria, little information exists on the molecular epidemiology and the lineage distribution of the Newcastle disease viruses (NDVs) in the country, especially in the live bird markets (LBMs). Recent studies reported the identification of three unique sub-lineages. namely; 5f, 5g and 5h in West Africa, and sub-lineages 5f and 5g in particular in non-commercial farms in Nigeria. In this study, 33 NDV isolates, which included NDVs recovered from LBMs in Nigeria, during active surveillance from 2007 to 2008 and viruses recovered from outbreaks in backyard and commercial chicken farms within the same period were analysed. Based on determination of the F(0) cleavage site amino acid sequence and phylogenetic analysis, the isolates were classified as virulent; 16 strains were identified as sub-lineage 5g and 17 as sub-lineage 5f. Interestingly, 13 strains from the 5f group formed a distinct cluster that was not identified by other groups in similar studies. The close genetic similarities identified, provided evidence for the first time of the epidemiological link between the viruses circulating in the LBMs and those recovered from outbreaks in backyard and commercial chicken farms in Nigeria between 2007 and 2008. The emergence and identification of new sub-lineages provide an insight into the high rate of genetic drift occurring in NDV strains in Nigeria, and raises a lot of concerns about the efficacy of current ND control measures in the country.

A molecular and antigenic survey of H5N1 highly pathogenic avian influenza virus isolates from smallholder duck farms in Central Java, Indonesia during 2007-2008

BackgroundIndonesia is one of the countries most severely affected by H5N1 highly pathogenic avian influenza (HPAI) virus in terms of poultry and human health. However, there is little information on the diversity of H5N1 viruses circulating in backyard farms, where chickens and ducks often intermingle. In this study, H5N1 virus infection occurring in 96 smallholder duck farms in central Java, Indonesia from 2007-2008 was investigated and the molecular and antigenic characteristics of H5N1 viruses isolated from these farms were analysed.ResultsAll 84 characterised viruses belonged to H5N1 clade 2.1 with three virus sublineages being identified: clade 2.1.1 (1), clade 2.1.3 (80), and IDN/6/05-like viruses (3) that did not belong to any of the present clades. All three clades were found in ducks, while only clade 2.1.3 was isolated from chickens. There were no significant amino acid mutations of the hemagglutinin (HA) and neuraminidase (NA) sites of the viruses, including the receptor binding, glycosylation, antigenic and catalytic sites and NA inhibitor targets. All the viruses had polybasic amino acids at the HA cleavage site. No evidence of major antigenic variants was detected. Based on the HA gene, identical virus variants could be found on different farms across the study sites and multiple genetic variants could be isolated from HPAI outbreaks simultaneously or at different time points from single farms. HPAI virus was isolated from both ducks and chickens; however, the proportion of surviving duck cases was considerably higher than in chickens.ConclusionsThe 2.1.3 clade was the most common lineage found in this study. All the viruses had sequence characteristic of HPAI, but negligible variations in other recognized amino acids at the HA and NA proteins which determine virus phenotypes. Multiple genetic variants appeared to be circulating simultaneously within poultry communities. The high proportion of live duck cases compared to chickens over the study period suggests that ducks are more likely to survive infection and they may better suit the role of long-term maintenance host for H5N1. As some viruses were isolated from dead birds, there was no clear correlation between genetic variations and pathogenicity of these viruses.

Risk factors for highly pathogenic avian influenza (HPAI) H5N1 infection in backyard chicken farms, Thailand

To reduce the risk of highly pathogenic avian influenza (HPAI) H5N1 infection in humans, the pathways by which HPAI is spread in poultry must be determined. Backyard poultry farmers are particularly vulnerable to the threat of HPAI, with both their health and livelihoods at risk. Identifying the risk factors for HPAI infection in backyard farms should allow control measures to be better targeted. To study the risk factors of HPAI H5N1 infection, we carried out a case-control study on backyard chicken farms in Thailand, analyzing 104 case farms and 382 control farms. Data on farming practices and environmental characteristics were analyzed using multivariate logistic regression models. We show that farms where owners bought live chickens from another backyard farm had a higher risk of HPAI H5N1 infection (OR 3.34, 95% CI 1.72–6.47), while those where owners used a disinfectant to clean poultry areas were exposed to lower risk (OR 0.48, 95% CI 0.26–0.87). Our results highlight the important role of the trade of poultry between farms in the transmission of HPAI H5N1, in addition to farming practices and environmental characteristics. Findings from this study may help to tailor prevention measures to the local circumstances of backyard farms in different regions of the world.

An epidemiological overview of swine trichinellosis in China

Trichinellosis is a major food-borne zoonosis with health, social, and economic impacts. Epidemiological data on swine trichinellosis in China from 2005 to 2009 were obtained from seven Provinces/autonomous regions/Municipalities (P/A/M) and analyzed and sero-epidemiological data were acquired from five P/A. The seroprevalence ranged from 0.01% to 29.95% as determined by enzyme-linked immunosorbent assay or an immunochromatographic strip method. The prevalence of Trichinella infection in swine slaughtered at abattoirs varied from 0% to 5.75% in five P/A. Between 2005 and 2009, endemic areas of swine trichinellosis were located mainly in the Western (Guangxi and Qinghai), central (Henan and Hubei), and North-eastern parts (Heilongjiang) of China. Swine trichinellosis in China is transmitted mostly through garbage. Pigs infected with Trichinella are predominately from small backyard farms where animals are raised under poor hygienic conditions, and from rural and mountainous areas where they range freely at pasture. The prevalence of Trichinella in pork sold at the market was reported in four P/A, and varied from 0.06% to 5.6% as determined by trichinoscopy or the digestion method. From 2005 to 2009, 15 outbreaks of human trichinellosis, with 1387 cases and 4 deaths, were recorded in three P/A of South-western China. Twelve (85.71%) of these 15 outbreaks were caused by the eating of raw or undercooked pork, which remains the predominant source of trichinellosis in humans. Pig-rearing practices must be improved, and mandatory inspection of pork further strengthened in rural and mountainous areas in Western China for the control of the disease.

Spatio-temporal model of avian influenza spread risk

HPAI virus has caused significant economic losses in the poultry industry. Backyard and outdoor poultry farms (BOPF) can play an important role in the spread of the disease. A spatio-temporal model has been developed to identify areas and periods at higher risk of HPAI spread in BOPF and applied on a Spanish region. Six risk factors were considered: Census, density, biosecurity, species susceptibility, proximity to risk wetlands and virus survival. A risk map was generated adding each risk factor as a spatial layer and a spatial-temporal analysis was conducted using scan statistics. Six clusters of spread risk of HPAI were identified in December and January. Despite the simplicity of the model, this system allows to focus the surveillance efforts in the highest risk areas and species. Thereby it could improve the efficiency of surveillance and control systems in terms of cost/benefit ratio

The development of a model for artificial insemination by backyard pig farmers in Thailand

The aim of this study was to develop and evaluate a model of artificial insemination (AI) technology transferable to backyard pig farmers for strengthening pig productivity in rural areas in Thailand. An AI center, criteria and process for farmer selection, an AI training program, AI practice in pigs, and a backyard farmer network were created as a model. Five hundred and thirty-one farrowing records from 307 sows were analyzed. Farrowing rates (FR), total number of piglets born (TB), and number of piglets born alive (BA) were studied. AI has led to better results in FR, TB, and BA than natural mating (P < 0.05). Demographic factors such as sex and age of farmers only had significant effects on FR (P < 0.05), while educational levels and farmers' AI experience had significant effects on TB and BA (P < 0.05). Model factors such as type of training, semen delivery systems, and semen storage time did not have significant effects on FR, TB, and BA. In conclusion, using this model, we found that backyard farmers could be trained in AI techniques in order to achieve equally good results as experienced technicians. Male farmers within working age or older, with a high school education or higher are the recommended target groups for implementing this model. Strong cooperation with clear responsibilities of all stakeholders could create a good network of backyard pig farmers. Therefore, the implementation of AI techniques in pig production can be applied to the target group with an aim towards a sustainable, self-sufficient community.

Characterization of influenza virus sialic acid receptors in minor poultry species

It is commonly accepted that avian influenza viruses (AIVs) bind to terminal α2,3 sialic acid (SA) residues whereas human influenza viruses bind to α2,6 SA residues. By a series of amino acid changes on the HA surface protein, AIVs can switch receptor specificity and recognize α2,6 SA positive cells, including human respiratory epithelial cells. Animal species, like pigs and Japanese quail, that contain both α2,3 and α2,6 SA become ideal environments for receptor switching. Here, we describe the SA patterns and distributions in 6 common minor domestic poultry species: Peking duck, Toulouse geese, Chinese ring-neck pheasant, white midget turkey, bobwhite quail, and pearl guinea fowl. Lectins specific to α2,3 and α2,6 SA (Maakia amurensis agglutinin and Sambuca nigra agglutinin, respectively) were used to detect SA by an alkaline phosphotase-based method and a fluorescent-based method. Differences in SA moieties and their ability to bind influenza viruses were visualized by fluorescent labeling of 4 different H3N2 influenza viruses known to be specific for one receptor or the other. The geese and ducks showed α2,3 SA throughout the respiratory tract and marginal α2,6 SA only in the colon. The four other avian species showed both α2,3 and α2,6 SA in the respiratory tract and the intestines. Furthermore, the turkey respiratory tract showed a positive correlation between age and α2,6 SA levels. The fact that these birds have both avian and human flu receptors, combined with their common presence in backyard farms and live bird markets worldwide, mark them as potential mixing bowl species and necessitates improved surveillance and additional research about the role of these birds in influenza host switching.

Backyard farm injuries assessment in rural area of Cluj County, Romania

Although 46% of the Romanian population lives in rural areas, little is known about injuries and violence rural residents experience. Research worldwide consistently shows that farm related activities are a...

Our Animals Ourselves

Although sociology has only recently turned to the study of animals, our society has long recognized their importance, whether asworkers to tow heavy trucks, friends to enjoy and play with, or protein to eat. Human relationships with animals started to change a century ago as technological advances ended our dependence on horses, industrialization of agricultural production replaced backyard farms, and urbanization encroached on the wilderness. Americans had fewer direct encounters with other animals, and those they did have were increasingly with pets or animals in zoos and circuses.