首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Despite the large numbers and importance of adapted indigenous sheep and goats in the tropics, information on sustainable conventional breeding programmes for them is scarce and often unavailable. This paper reviews within-breed selection strategies for indigenous small ruminants in the tropics, highlighting aspects determining their success or failure. The aim is to better understand opportunities for genetic improvement of small ruminants by the resource-poor farmers in traditional smallholder and pastoral farming systems. Dismal performance of programmes involving breed substitution of exotics for indigenous breeds and crossbreeding with temperate breeds have stimulated a recent re-orientation of breeding programmes in tropical countries to utilize indigenous breeds, and most programmes are incipient. The success rate of some breeding programmes involving native breeds is encouraging. Definition of comprehensive breeding objectives incorporating the specific, immediate, and long-term social and economic circumstances of the target group as well as ecological constraints was found lacking in some projects that failed. To achieve success, it is necessary to look at the production system holistically, and involve the producer at every stage in the planning and operation of the breeding programme, integrating traditional behaviour and values.  相似文献   

2.
《Small Ruminant Research》2009,87(1-3):52-55
The status of scrapie in Africa is largely unknown. The susceptibility to scrapie and its pathology is determined by amino acid polymorphisms at positions 136 (A/V), 154 (R/H) and 171 (Q/R/H) of the ovine PrP gene (PrP genotype) of the animals. Despite the widely studied PrP gene polymorphisms worldwide, limited data is available on PrP genotypes of sheep from the African continent. Previously, we have reported six PrP genotypes derived from four different alleles in Red Maasai and Black Herd Persian (BHP), the ARQ/ARQ genotype being more frequent in the Red Maasai than in the BHP sheep. The highly susceptible VRQ allele was not found in any of the sheep breeds; the ARR allele was absent in the Red Maasai or occurred at a low frequency in the BHP. The lack of the highly susceptible VRQ alleles among Tanzanian sheep examined, necessitated further examinations on genetic susceptibility in sheep of the same breeds, but originating from an entirely different part of Tanzania. Consistently, ARQ/ARQ genotype was observed in 88% of Red Maasai and 64% of BHP sheep, ARQ/AHQ genotype was present in 12% in Red Maasai and 36% in BHP. Neither the highly resistant (ARR/ARR), nor the highly susceptible (VRQ/VRQ) genotypes were found. The ARQ and AHQ were the only alleles observed. The ARQ allele constituted 94%, 82% and 67% in the Red Maasai, BHP and cross-bred sheep, respectively. The AHQ constituted 6%, 18% and 33%, respectively. Data reported here, provide additional information on genetic susceptibility of the Red Maasai, BHP and their crosses; they may be helpful in policy formulation for future prevention of scrapie.  相似文献   

3.
In this paper, I examine patterns of wealth accumulation and their influence on deforestation among smallholders at Uruará and Redenção, in the state of Pará in the Brazilian Eastern Amazon. I argue that the development of the smallholder economy has not been a linear process, and the diversity of smallholder farming systems and their patterns of wealth accumulation have varied implications for the rate and magnitude of deforestation. However, whilst there are differential impacts of farming practices on deforestation—cattle ranching has a greater impact than cash cropping or subsistence agriculture—the stronger correlate of deforestation is the wealth of the farmers. Wealthier farmers not only tend to deforest more in absolute terms, but also show a slightly greater propensity to deforest whatever their production system. Though cattle production is a key driver of wealth accumulation and thus deforestation, a significant number of smallholders adopt diversified production systems. The main factors explaining the relationship between the farming systems and deforestation were years of residence on the lot, distance of the lot to main market and the amount of day labor hired—and not variables describing household structure.  相似文献   

4.
This paper aims to explore farmers’ preferences for sheep or goats based on feeding practices, animal and flock performances and economic benefits of sheep and goats in different agro-ecological zones in Central Java, Indonesia. In total, 150 smallholder farmers were selected from three agro-ecological zones: the lowlands, the middle zone, and the uplands. Feeding and performance parameters were estimated through weekly farm visits and farm records, from September 2001 to August 2003. In the lowlands, small ruminants were fed mainly with field grass and crop residues, whereas in the middle zone and uplands feeds fed were mainly field grass and leaves. Sheep were given more opportunities to graze than goats, however, grazing was not a major component in the diets. In the lowlands and the middle zone the differences in feed intakes, ADG and reproductive performances between sheep and goats were small. In all zones, does had significantly larger litters than ewes. In the uplands, goats had a significantly higher DMI, grew slightly faster, and had a higher weaning rate than sheep. Consequently, in the uplands, the total economic benefits from goat flocks were 25% higher than from sheep flocks. The major differences in agro-ecological conditions that affect the choice for sheep or goats were the availability of cassava peels in the lowlands, favouring a choice for sheep, and the abundance of leaves in the middle zone and uplands, which favours keeping goats. The promotion of goats by the government, the family tradition of keeping sheep or goats, the preference for sacrificing sheep for religious festivities, and the high initial investment needed to buy goat breeding stock could be other important motives to keep sheep or goats. Sheep fattening based on rice bran supplementation could be a feasible innovation in the lowlands. In the middle zone and uplands goat breeding could make a positive contribution to rural livelihoods.  相似文献   

5.
Maasai pastoralists in Kenya are rapidly diversifying. Maasai may now derive their main livelihoods (and sometimes considerable income) from farming, wildlife tourism, and/or the leasing of land for large-scale cereal cultivation. The spread of large-scale commercial cultivation competes with wildlife for grazing land, and wildlife populations around protected areas are rapidly declining as a result. This paper presents new data to analyse the way returns from different land uses, and the social structures affecting their distribution, influence the land-use choices being made by Maasai around the Mara National Reserve in Kenya. Returns to different interest groups from livestock, cultivation, and wildlife enterprises, seen in the light of current social, economic, and political trajectories, can help to clarify likely future land-use trends in the Mara. In particular, community conservation initiatives that seek to make conservation worthwhile to reserve-adjacent dwellers inevitably have a strong economic dimension. However, the choices made by Maasai landowners are not a simple function of the economic returns potentially accruing from a particular enterprise. They are as much or more influenced by who is able to control the different flows of returns from these different types of enterprise. These findings are relevant not only for the wider Serengeti-Mara Ecosystem, but also for pastoral livelihoods and wildlife conservation elsewhere in sub-Saharan Africa.  相似文献   

6.
In the last decade, community-based animal breeding programs have gained attention for the genetic improvement of small ruminants in the tropics. Nevertheless, implementing such programs remains challenged by the issue of smallholders' participation. To shed light on this issue of participation, a goat genetic improvement project has been assessed for its socioeconomic relevance through participatory methods, taking account of goat multifunctionality. We quantified the gross margins per flock and per animal as indicators of viability. We assessed then the correspondence between the goat functions defined through a proportional piling tool with the relative share of these functions in the gross revenue. For that purpose, 160 smallholders were surveyed and 77 among them were monitored for one year. A cluster analysis of factors linked to the dynamic of goat farming identified three groups of farmers. The first group gathered farmers with the smallest goat flocks, who were goat oriented in the future. Their sustainable participation in goat breeding project was impeded by the excessive sales of goats. The second group involved farmers with the highest farm size, who planned to buy cattle to replace part of their goats. The third group included farmers who were members of the project with the largest goat flocks. This group emphasized the importance of goat for their future but showed weak abilities to manage large flocks. The gross margin per animal was the highest in the third group. The relative importance of goat functions as defined through participatory tools did not correspond to the relative share of these functions in the composition of the gross revenue from goats. Participatory tools and economic calculation then appear as complementary to understand farmers' priorities. Consolidating breeders' associations and supporting farmers to diversify their sources of income are two ways proposed here to ensure an enabling environment to goat husbandry and farmers' well-being.  相似文献   

7.
We evaluated the efficiency of selection for body weight in a cooperative village breeding program for Menz sheep of Ethiopia under smallholder farming system. The design of the program involved organizing villagers in a cooperative breeding group to implement selective breeding of their sheep. The program was jump-started through a one-time provision of elite rams from a central nucleus flock, but subsequent replacement rams were selected from within the village flocks. We also evaluated body weight trends in a village where cooperative breeding was not implemented and individual farmers managed their flocks under traditional breeding practices. Under traditional breeding practices, genetic progress over 8 years either stagnated or declined in all the weights recorded. In the cooperative villages, selection differentials of 2.44 and 2.45 kg were achieved in 2010 and 2011 selection seasons, respectively. Birth weight, 3-month weight and 6-month weight increased, respectively, by 0.49, 2.29 and 2.46 kg in the third-generation lambs over the base generation. Improved rams supplied from the central nucleus flock gave an initial genetic lift of 14.4% in the 6-month weight. This was higher than the gain achieved from selection in the village flocks, which was 5.2%. Our results showed that village-based genetic improvement in body weights under smallholder conditions could be feasible if appropriate designs are adopted and that commencing with elite central nucleus rams help jump-start village-based programs.  相似文献   

8.
The biodiversity and climate consequences of oil palm (Elaeis guineensis) expansion across South East Asia have received considerable attention. The human side of the issue, highlighted with reports of negative livelihood outcomes and rights abuses by oil palm companies, has also led to controversy. Oil palm related conflicts have been widely documented in Indonesia yet uptake by farmers has also been extensive. An assessment of the livelihood impacts of oil palm development, including sources of conflict, is needed to shed light on the apparent contradiction between these reports and the evident enthusiasm of farmers to join the oil palm craze thereby informing future expansion. We assessed the impact of oil palm development on the economic wellbeing of rural farmers in Indonesia. We found that many smallholders have benefited substantially from the higher returns to land and labour afforded by oil palm but district authorities and smallholder cooperatives play key roles in the realisation of benefits. Conflicts between communities and companies have resulted almost entirely from lack of transparency, the absence of free, prior, and informed consent and unequal benefit sharing, and have been exacerbated by the absence of clear land rights. We make specific recommendations to improve the present situation and foster the establishment of smallholder friendly production regimes. Oil palm expansion in Indonesia is set to continue. If environmental standards can be raised and policy interventions targeted at the broader social impacts of land development this expansion may be achieved to the significant benefit of large numbers of rural smallholders.  相似文献   

9.
The European small ruminants (i.e. sheep and goats) farming sector (ESRS) provides economic, social and environmental benefits to society, but is also one of the most vulnerable livestock sectors in Europe. This sector has diverse livestock species, breeds, production systems and products, which makes difficult to have a clear vision of its challenges through using conventional analyses. A multi-stakeholder and multi-step approach, including 90 surveys, was used to identify and assess the main challenges for the sustainability of the ESRS to prioritize actions. These challenges and actions were identified by ESRS experts including farmers, cooperatives, breeding associations, advisers and researchers of six EU countries and Turkey. From the 30 identified challenges, the most relevant were economy-related challenges such as ‘uncertainty of meat and milk prices’, ‘volatility of commodity prices’, ‘low farm income’, ‘high subsidy dependency’ and ‘uncertainty in future changes in subsidies’ resulting in ‘a sector not attractive to young farmers’. Most of these challenges were beyond the farmer’s control and perceived as difficult to address. Challenges were prioritized using an index, calculated by multiplying the relevance and the feasibility to address measures. The identified challenges had a similar priority index across the whole sector with small differences across livestock species (sheep vs goats), type of products (meat vs dairy) and intensification levels (intensive vs semi-intensive vs extensive). The priorities were different, however, between socio-geographical regions (Southern vs Central Europe). Some of the top prioritized challenges were linked to aspects related to the production systems (‘low promotion of local breeds’ and ‘slow adaptability of high producing breeds’) and market practices (‘unfair trade/lack of traceability’). The majority of the priority challenges, however, were associated with a deficient knowledge or training at farm level (‘poor business management training’, ‘lack of professionalization’, ‘slow adoption of innovations’), academia (‘researchers do not address real problems’) and society as a whole (‘low consumer education in local products’, ‘low social knowledge about farming’, ‘poor recognition of farming public services’). Thus, improved collaboration among the different stakeholders across the food chain with special implication of farmers, associations of producers, academia and governments is needed to facilitate knowledge exchange and capacity building. These actions can contribute to make ESRS economically more sustainable and to adapt the production systems and policy to the current and future societal needs in a more region-contextualized framework.  相似文献   

10.
Precision livestock farming (PLF) technologies are becoming increasingly common in modern agriculture. They are frequently integrated with other new technologies in order to improve human–livestock interactions, productivity and economical sustainability of modern farms. New systems are constantly being developed for concentrated farming operations as well as for extensive and pasture-based farming systems. The development of technologies for grazing animals is of particular interest for the Mediterranean extensive sheep farming sector. Dairy sheep farming is a typical production system of the area linked to its historical and cultural traditions. The area provides roughly 40% of the world sheep milk, having 27% of the milk-producing ewes. Developed countries of the area (France, Italy, Greece and Spain – FIGS) have highly specialized production systems improved through animal selection, feeding techniques and intensification of production. However, extensive systems are still practiced alongside intensive ones due to their lower input costs and better resilience to market fluctuations. In the current article, we evaluate possible PLF systems and their suitability to be incorporated in extensive dairy sheep farming as practiced in the FIGS countries. Available products include: electronic identification systems (now mandatory in the EU) such as ear tags, ruminal boluses and sub-cutaneous radio-frequency identification; on-animal sensors such as accelerometers, global positioning systems and social activity loggers; and stationary management systems such as walk-over-weights, automatic drafter (AD), virtual fencing and milking parlour-related technologies. The systems were considered according to their suitability for the management and business model common in dairy sheep farming. However, adoption of new technologies does not take place immediately in small and medium scale extensive farming. As sheep farmers usually belong to more conservative technology consumers, characterized by an average age of 60 and a very transparent community, the dynamics do not favour financial risk taking involved with new technologies. Financial barriers linked to production volumes and resource management of extensive farming are also a barrier for innovation. However, future prospectives could increase the importance of technology and promote its wider adoption. Trends such as global sheep milk economics, global warming, awareness to animal welfare, antibiotics resistance and European agricultural policies could influence the farming practices and stimulate wider adoption of PLF systems in the near future.  相似文献   

11.
The reproductive performance of ewes and the survivability of lambs to weaning have a critical economic impact on sheep farming worldwide. Further, knowledge of major mortality causes allows an opportunity for improved flock management to evade financial losses. The maximum likelihood estimates for generalised linear mixed models and chi-square test methods were used to examine 971 mating records, 839 and 763 lambs born and weaned (singles or twins) from the Naivasha Sheep and Goats station in Kenya for the years 2011 to 2020 consisting of Dorper, Red Maasai (RedM), and Merino breeds. The RedM (P < 0.05) outperformed Dorper and Merino in weaning rate, whereas reproductive performance between the three breeds was not significantly different (P > 0.05) in litter size and multiple lambings per ewe lambing. On the one hand, Dorper significantly (P < 0.05) outperformed the other two breeds only in weaning weight per lamb born. In addition, among all the major causes of death, pneumonia appeared to be the one to which Dorper breeds were most susceptible (chi-square test, P < 0.05). According to the findings of this study, neither the Dorper nor the Merino sheep breeds were reproductively superior to the RedM in an extensive semi-arid production environment. In addition, Dorper's susceptibility to the leading causes of mortality, particularly pneumonia and sheep pox, were relatively high compared to other breeds and could be a precursor to massive economic losses for Dorper sheep producers. In contrast to the indigenous RedM breed, imported sheep breeds appeared to be more susceptible to major mortality-related under an extensive production system. Therefore, regardless of weaning weight, RedM breed production appears to be a more viable investment for small-scale farmers, particularly in semi-arid regions.  相似文献   

12.
In the Web Valley of the Bale Mountains National Park, the pastoral people suffer from livestock predation by wild carnivores. A total of 704 livestock were reported to be killed by wild carnivores over a 3‐year period, causing a loss of potential revenue of 12 USD per year per household. Reported annual predation rates equated to 1.4% of the livestock population of the study area. Spotted hyaenas were responsible for most livestock predation (57%), followed by leopards (18%), common jackals (16%) and servals (9%). Hyaenas killed all livestock types (horses, donkeys, mules, cattle, goats and sheep) whilst leopards, common jackals and servals killed mostly goats and sheep. A survey of 362 households revealed that the pastoral people keep dogs to protect livestock from carnivores. During 250 nights of observation in the ten settlements, pastoralists were alerted to the presence of hyaenas on 80 occasions by the barking of their dogs. Such tradition of keeping dogs presents a threat to the persistence of the endangered Ethiopian wolf through diseases transmission. Given the frequency of carnivore attacks on livestock, it is desirable to develop alternative livestock protection methods that both minimize livestock losses and reduce the risk of disease transmission to Ethiopian wolves.  相似文献   

13.
The serosurveys conducted in the Silica plateau area of the Slovak karst region revealed the presence of specific neutralizing antibody against tick-borne encephalitis (TBE) virus in 18% of local inhabitants (33 examined, mostly goats and sheep farmers), 54% of goats (26 examined), 18% of sheep (120 examined) and 13% of cattle (60 examined), against Lipovník (LIP) virus in 30% of inhabitants, 88% of goats, 55% of sheep and 45% of cattle, and against Bhanja (BHA) virus in 27% of inhabitants, 46% of goats, 29% of sheep and 23% of cattle. The results of hemagglutination-inhibition tests with TBE and BHA antigens were analogous. A detailed analysis of these serologic data points to a recent enhancement of the circulation of LIP and BHA viruses and to a very low TBE virus activity in this natural focus of arboviral infections. The immunological surveys of the 32 former "Roznava disease" patients, conducted 25 years after an extensive epidemic of a TBE virus infection that originated in Roznava in 1951, revealed the presence of neutralizing (and also hemagglutination-inhibiting) antibodies against TBE virus in as many as 78% of cases. Antibodies against LIP and BHA viruses were also detectable in the sera of 16% and 9%, respectively, of these individuals. Populations of the ectoparasites examined for the presence of arbovirus comprised 231 Ixodes ricinus, 806 Dermacentor marginatus and 204 Haemaphysalis punctata ticks and 117 specimens of the louse-flies Melophagus ovinus. Two strains of arbivirus that were antigenically related to Lipovník and Tribec viruses belonging to a group of Kemerovo viruses were isolated from male and female I. ricinus ticks collected from cattle.  相似文献   

14.
Sheep and goat farming is a major source of income in the rural areas of Al-Wadiah in Najran region of Southern Saudi Arabia. The study aims to identify the factors and parameters that influence gender participation in sheep and goat farming. Data were collected by interviewing 167 high school students, including 70 male and 97 female students, in Al-Wadiah, by using the simple random sampling technique. Data were statistically analyzed to establish the relationship between gender and participation in sheep and goat farming. The study revealed significant differences between the two genders, for instance, male herders were more experienced, received more benefits, showed greater interest in discussions on topics related to sheep and goat farming, followed information from TV and radio, and received more services offered by veterinary clinics, which proved more beneficial for them. On the other hand, female herders received fewer services, and the veterinary clinics proved less beneficial for them. However, the correlation between the participation of both genders in sheep and goats management was non-significant toward the statement “feeling ashamed of participating in sheep and goat farming.” Generally, sheep and goat rearing proves more beneficial for male participants than female participants, owing to their greater experience and interest in livestock farming. Moreover, they receive more benefits from TV, radio and veterinary clinics to maintain better health of their livestock. Both male and female herders contribute equally to sheep and goat farming by limiting the time spent on their daily routine. This study would enable policymakers and planners to develop more strategies and extension education programs to overcome the identified barriers and improve the livelihood of herders through their enhanced participation in remote areas.  相似文献   

15.
A study was conducted in the Sahelian zone of Burkina Faso of the behaviour of cattle, sheep and goats on natural pasture and their preference for browse species. Concurrently, a survey was undertaken on a sample of farmers (herders, women and livestock owners) in the study area to estimate the indigenous knowledge of browse species and their utilisation by ruminants. A herd of cattle and flocks of sheep and goats belonging to farmers were followed on pasture, each species during three consecutive days each month, from May 2003 to April 2004, and their activities were recorded regularly every 15 min, as well as the browse species selected and the height reached while browsing. The farmers had good knowledge of the browse species present in the area and their preferential classification depended on the availability of the species, their nutritive value and also other ways of utilising the species concerned. However, some divergence existed in the knowledge of farmers compared to the result from the behaviour study, e.g. some species were mentioned by farmers but not found in the inventory. There was a decline in the feeding activities of all animal species from rainy to dry season, while resting and ruminating activities were increasing at the same time. This decline in time spent feeding was more important for cattle (from 72 to 39% of total time) as they relied on the herbaceous biomass for feeding, while sheep and goats made a shift in the feeding activities from grazing to browsing when the herbaceous biomass decreased. Cattle browsed (leaves and litter) during all the study period for around 4.5% of the time spent on pasture. Sheep and goats showed a peak in browsing activity in the dry season, 28 and 52% of the time, respectively. During the whole observation period, cattle browsed 10 species, with Guiera senegalensis most often selected, with 59, 54 and 84% of browsing time, respectively, in the rainy, post rainy and dry season. G. senegalensis, Combretum micranthum and Balanites aegyptiaca were the most important species browsed by sheep among the 20 browse species selected. Goats browsed more than 20 species daily but the most preferred species were Acacia senegal, B. aegyptiaca and Pterocarpus lucens. The mean height reached by goats when browsing was higher (1.65 m) than that of cattle (1.47 m) and sheep (0.87 m). The result from this study can be used to select species for regeneration and to advice farmers on the importance of herd composition.  相似文献   

16.
Crossbreeding of indigenous tropical and improved western dairy cattle breeds as tool to improve dairy cattle performance on smallholder farms has been widely advocated, criticised and yet applied. The government of Ethiopia supported this technology for decades but adoption rate is low. Constraints are documented but there is little information about farm level introduction and development of crossbreeding. A total 122 smallholders with mixed crop livestock farms and at least 8 years of successful crossbreeding were interviewed using a pre-tested questionnaire in two contexts in Amhara Regional state in north-western Ethiopia. Crossbreeding initiator was either uncoordinated government extension or a coordinated development project, also implemented with governmental support. Qualitative and quantitative data on farmers’ motivations, crossbreeding introduction, initiator support, breeding adaptation and impacts at farm level were analysed. Results show that even though motives vary between contexts the underlying reason to introduce crossbreeding was economic profit. To be able to introduce crossbreeding support of initiators (e.g. extension) and other farmers was essential. The crossbreeding introduction context had some influence. Governmental actors were the main source of support and supplier of exotic genetics but the farmer network acted as safety net filling gaps of government support. Breeding strategies focused on performance increase. A lack of basic understanding of crossbreeding has been identified. A surprising, probably biased, result was general satisfaction with initiator support and with breeding services. It was challenged by the high proportion of farmers unable to follow a breeding strategy due to insufficient bull and/or semen supply. Crossbreeding changed the smallholder production system to a high input – high output system. Except for crossbred adaptation problems, challenges were ranked context specific and influenced by the initiator. Farmers perceived crossbreeding as success and recommended it. We conclude that farmers can realize income increase with crossbreeding. The complexity of this technology, high initial investment and the need for support services and external production inputs are probable reasons why crossbreeding uptake is low. Improving the availability of semen and/or bulls must be the top priority for breeding service providers to enable farmers to follow a breeding strategy and reach a suitable and sustainable herd performance. Access to investment capital, input supply, strong technical support and market linkages are crucial for successful crossbreeding.  相似文献   

17.
Scrapie, a transmissible spongiform encephalopathy (TSE) or prion disease, is a fatal, neurodegenerative disease in sheep and goats. This disease has been known in Europe for more than 250 years. Susceptibility to scrapie is associated with polymorphisms in the sheep prion protein gene (PrP) gene. In sheep, polymorphism in the PrP gene has been identified at a number of codons, and polymorphisms at codons 136, 154 and 171 have reported linkage with susceptibility to scrapie. Polymorphisms at the PrP locus were studied in 413 animals representing three native sheep breeds (Imroz, Chios and Kıvırcık) in Turkey. Genomic DNA was obtained from blood, and genotypes were screened using PCR and direct DNA sequencing. We report 17 genotypes derived from seven different alleles. The most frequent genotype in the Kıvırcık sheep is ARQ/ARQ, whereas the ARR/ARQ genotype is predominant in the Chios and Imroz breeds. In general, the ARQ haplotype was the predominant haplotype. ARQ haplotype was also predominant in the Kıvırcık and Chios sheep breeds, whereas the Imroz sheep predominantly had the ARR haplotype. The susceptibility-associated VRQ haplotype was found in 2.38%, 0.35% and 0.81% of the Imroz, Kıvırcık and Chios sheep, respectively. Moreover, seven additional polymorphisms have been detected at codons G127S, G127V, H143R, G145S, Y172D, N174Y and Q189L. Among these polymorphisms, the N174Y allele is a novel polymorphism, and the G145S allele is a novel allele for a known polymorphic locus.  相似文献   

18.
19.
Relocating plants from swidden fallows to gardens in Southwestern China   总被引:1,自引:0,他引:1  
As upland farmers in Southeast Asia change from shifting cultivation to permanent agriculture and lose access to swidden-fallow forests and their resources, they are introducing economically important forest and fallow plants into their house gardens. We describe this process in Daka, a village of Hani ethnicity in Yunnan Province, China. Daka smallholders collect both seeds and seedlings from fallow forests and transfer the plants to house gardens, initiating the transformation of wild species to a cultivated or semi-domesticated one. Two kinds of species are commonly transferred from swidden fallows to house gardens. Some are particularly rare, others are plants in great demand. Between 1998 and 2000 Daka households earned an average of US$68.20 annually from the products of fallow forests. We also found that villagers harvest and use 76 plant species from fallow forests and 126 species from house gardens. Twenty-two species found in house gardens that had been transferred from fallow forests. Households vary widely in the frequency with which they engage in this pattern. We believe that local knowledge of these practices is a potentially important resource in the development of other areas of smallholder farming.  相似文献   

20.
This paper examines how oil palm migrant farmers in Papua New Guinea are responding to shortages of land for food gardening. Despite rapid population growth and planting nearly all of their land to oil palm, virtually all families continue to grow sufficient food for their families. The paper outlines the diverse range of adaptive strategies that households have employed to maintain food security, involving both intensification and innovation in farming systems. While gains from intensification have been significant and built resilience, they have been incremental, whereas innovation has been transformative and led to large gains in resilience. The adoption of more flexible land access arrangements on state leasehold land that ‘revive’ and adapt indigenous systems of land sharing and exchange that operated through kinship networks on customary land are innovative; they have increased the supply of land for food gardening thereby reducing risk for individual households and the broader smallholder community. The paper highlights the value of understanding farmer-driven innovations and the role of indigenous institutions and cultural values in sustaining and enhancing household food security.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号