Evaluation of uncultivated vegetables for pigs kept in upland households

Ngo Huu Toan and T R Preston*

Hue University of Agriculture and Forestry,
Hue, Vietnam
ngohtoan@yahoo.com
* TOSOLY, AA48 Socorro, Colombia
 

Abstract 

Formal and informal interviews and survey activities were conducted to compile data on what kind of uncultivated vegetables the farmers used for pigs in 4 upland communes in two mountainous districts in Thua Thien Hue province. Information was obtained on their seasonal availability and adoptability, the parts used as pig feed, and variation of adopted uncultivated vegetables according to wealth ranking between pig raisers. Their chemical composition was also analysed to see differences during the dry and wet seasons 

There are 14 kinds of uncultivated vegetables used as pig feed resources in upland areas. Three  of them were adopted all the year round such as Taro, Banana stem, and natural sweet potato leaves. The poorer farmers were the more intensive users of these feeds compared to medium and better-off pig raisers. Use of the vegetables led to lower production cost and higher net income achieved from pig production. 

Key words: income, interviews, pig feed resources, taro, uncultivated vegetables

Introduction

In the mountainous areas of Central Vietnam, uncultivated vegetables are used as the main feed source for pig raising. Presently, farmers cannot slash and burn completely because of the strict law; furthermore, many reforestation programs have been carried out in this area so the land became limited (Le Quang Minh 2001; Le Van An 2001). As a result, the farmer’s priority for their land is to produce food for human consumption requirements rather then for other purposes, eg. pig raising. This made the farmers depend more and more on uncultivated vegetables to feed their pigs throughout the year.  

Uncultivated vegetables have therefore become more popular and today have a very important role in the pig feeding systems in the mountainous communes. Ogle et al (2003) have studied the multiple functions of edible wild plants in VietNam. Over 90 species of edible wild plants was obtained from 4 villages in the Mekong Delta and the Central Highlands;  40% of them were used as livestock feeds (Nguyen Nhut Xuan Dung 1996). The micronutrient composition of some gathered vegetables was analyzed by Ogle et al (2001). However, although the quantitative use of uncultivated vegetables in pig diets has been measured there is little knowledge of their nutrient value. Furthermore, data on the evaluation of uncultivated vegetables in the diet with respect to source, levels, digestibility, and nutrient value for growing pigs have not been reported in the Central region.    

In order to obtain more knowledge about these uncultivated vegetables, surveys on their potential (biomass productivity, seasonal availability, variation between years etc), and nutritive value have been carried out. An inventory of these sources was compiled. The overall aim was  to convince the minority farmers to use them more effectively so as to improve pig feeding and productivity. 

The following hypotheses were tested:

·  Many kinds of uncultivated vegetables are used for pig production.

·  Uncultivated vegetables are available throughout the year for pig feeding.

·  Data on their chemical composition and cost: benefit ratio show that they make a valuable contribution to the net income gained from pig production in different groups of pig raisers (better-off, medium, poor).
 

Materials and methods 

Formal and informal interviews were used to understand what kinds of uncultivated vegetables the farmers commonly use for pig raising, and what are their characteristics, seasonal biomass, and variation between the years and where the farmers can collect them during the year.

The district Agricultural officers and Grass root extension workers, who are working with minority groups in the mountainous areas, and minority pig raisers, were interviewed to collect data. Some tools were also used like time limiting analysis, scale games, mapping and questionnaires (Mikkelsen 1994). 

A survey was conducted in two upland districts in Hue province (Aluoi and Nam Dong districts). Two communes per district were selected for investigation (Hong Ha and Huong Nguyen communes in Aluoi district, and Huong Huu and Thuong Lo communes, in  Nam Dong district. In these communes, 126 households that are raising pigs (an average of 24.4% of total pig raisers in the targeted areas) were interviewed according to wealth ranking as given below:

Information for 3 household categories (better off, medium and poor) was collected on:

• Feed resources available at household level (focused on natural vegetables)

• The number of uncultivated vegetables the farmers used daily, monthly, and yearly for pig raising.

•  The household planning of using uncultivated vegetables

• Benefit from pig production fed by uncultivated vegetable sources.

• Constraints and opportunities 

Children were involved to participate in collecting wild vegetables (Hart 1997). Samples of uncultivated vegetables were collected every month in dry (from February to June) and wet seasons (from September to January) and analyzed for DM, CP, EE, CF, Ash, and OM.

The SPSS software was used to analysis the data.

 

Results and discussion

Seasonal availability and adoptability

By applying stone-game approach to the pig raisers in targeted areas, 14 kinds of uncultivated vegetables were found as pig feed (Table 2). Three of them (Taro, banana stem, and wild sweet potato leaves) were available all the year round in upland areas of Thua Thien Hue. In the rainy season, pig raisers in the targeted areas were also able to collect several kinds of uncultivated vegetables in the forest for their pigs.

Natural taro and banana stem were adopted for pig feeding with the largest amount compared to others. This indicates that Taro and Banana were available in the forest in targeted areas all year round. They have become, therefore, the main uncultivated vegetables used as pig feed resources in Thua Thien Hue upland area. Results from the interviews showed that pig raisers could get them easily twice per week in the forest near their fields and bring them back home and keep for 2-3 days for use. This is a great potential in upland compared to lowland areas. The lowland pig raisers have to grow Taro and Banana in order to meet pig feed requirements. Thus, Taro and Banana were uncultivated vegetables in the upland area, while they became cultivated ones in the lowland area. As a result, cost of pig production in the upland area was reduced due to the availability of these “free” feed resources collected in the forest.        

Parts of uncultivated vegetables used for pig feeding

The parts of uncultivated vegetables used for pig feeding were also identified (Table 3).  

It is very important to know whether there was an over-exploitation of these vegetables for purposes of pig feeding. Natural vegetables can be considered as a kind of tree with good re-growth ability, if the roots are not harvested. The stems and leaves of the vegetables given in table 3 were the main parts harvested, without any damage to their roots (excluded one kind of Taro named Alocasia odora C. Koch),  so the plants survive and re-grow fast for the next harvest. On the other hand, the total area of forest in the targeted areas is quite big so the rotation of the harvest was quite good for sustainable adoption.     

Adoptability according to household categories

All interviewed pig raisers, in all household categories, used Taro as a feed resource for their pigs (Table 4).

The poor farmers adopted Taro (100%), Banana (91.8%), and Sweet potato leaves (91.8%) while medium pig raisers used Taro (100%) and Sweet potato leaves (72.7%), and better off ones used Taro (100%) for their pigs. The results also show that the poor farmers collected uncultivated vegetables for their pigs with a higher amount than medium and better off pig raisers. This indicates that the poor farmers raised their pigs with greater dependency on natural resources than richer farmers. For the poor farmers, use of uncultivated vegetables was the major strategy to reduce costs. However, lack of capital and technical know-how were the main problems the poor farmers faced in targeted areas, with resulting poor performance of their pigs (eg:  their pigs reached a live weight of only 40 kg after 6 months).

Benefit cost analysis

Benefit cost analysis was made to compare net income gained from pig production in different household categories (table 5).  

There were significant differences in net income between the household categories. As mentioned earlier, the poor farmers got the highest benefit from pig production because they mainly based their production system on feed collected from natural resources (including uncultivated vegetables) which were free of charge. The better-off pig raisers had the lowest net income because they fed their pigs with large amounts of purchased concentrates. Their pigs grew faster (eg: 55 kg live weight after 6 months raising) but they had the highest production cost compared to the others.   

For this reason, uncultivated vegetables play a very important role in pig production in upland areas.

Chemical composition analysis

The chemical composition of the uncultivated vegetables used in the targeted areas varied according to the dry and rainy seasons.  In the rainy season (Table 6), the DM content of uncultivated vegetables was lower than in the dry season (Tables 7). The CP content ranged from 9.2 % in DM (Musa balbisiana Colla) to 31.1% in DM (Piper lolot DC); thus they were an important source of protein to the pigs raised in upland areas. Similar findings were reported by Nguyen Nhut Xuan Dung (1996) on the use of non-cultivated plants as live stock feed in the Mekong delta.

Taro was available all year round in the forest in the targeted areas. It made a major contribution to the pig nutrition in the households of the poorer farmers. The range of CP content (14.1 to 15.2 % in DM depending on seasons) showed that it was a very good protein supplement to the pig diets. Wild Banana stem had a low CP content (5.5 to 9.2% DM), nevertheless it was an important feed resource especially for pigs in the rainy season in the households of the poorer farmers.

Analysis was done on the whole vegetative part of Taro (stems and leaves). This could be realistic to Vietnam Farmers who always use the  whole vegetative part of Taro as well as sweet potato and groundnut vines and leaves for pig raising.     
 

Conclusions and recommendations

Conclusions

• Fourteen kinds of uncultivated vegetables were used as pig feed resources in the targeted areas. Three of them (Taro, Banana stem, and Wild sweet potato leaves) were used all year round as major components of the diet for pig feeding.  

  
  

• There was a significant difference in access to these uncultivated vegetables among pig raisers related to their wealth standing. The poor farmers made greater use of these resources than the medium and better-off farmers. 

  
  

• Uncultivated vegetables are a very important feed resource for pigs raised by minority people in Thua Thien Hue upland areas; as they played a very important role in contributing to the nutrition of the pigs and to the net income from pig production for the poorer farmers  in the upland areas.   

Recommendations

• There is a great need for studies on Taro, which is a very popular vegetable resource for pigs in the Central Region of Vietnam. More information is required about the different species:  their characteristics, biomass production, seasonal availability, re-growth capacity, adaptability, potential contribution to pig diets, and the best ways of processing the plant for better use by the pigs.  
   

Acknowledgements

Support from the MEKARN Project, financed by the Swedish International Development Cooperation Agency – Department for Research Cooperation (SIDA/SAREC), is gratefully acknowledged. We also would like to thank Dr Le Duc Ngoan, Vice Rector of Hue University of Agriculture and Forestry, Vietnam and Dr Britta Ogle, Uppsala University, Sweden for their valuable advice and comments.  

 

References

Hart R A 1997 Children’s participation. The theory and practice of involving young citizens in community development and environmental care. Earthscan Publications Ltd.

Le Quang Minh 2001 Study on intervention that effect to natural resources in Hong Ha commune, A Luoi District, Hue province. In Research Results in stage of 1998 - 2001- Community based natural resources management project, under the supports from Hue University of Agriculture and Forestry and IDRC, Canada. Agricultural Publishing house, HaNoi 2002. Pp121-141

Le Van An 2001 Characteristics of Hong Ha commune, its advantages and difficulties, and some proposed solutions to community development. In Research Results in stage of 1998 - 2001- Community based natural resources management project, under the supports from Hue University of Agriculture and Forestry and IDRC, Canada. Agricultural Publishing house, HaNoi 2002. pp23-31

Mikkelsen B 1994 Methods for development work and research. A guide for practitioners. Copenhagen, Denmark, SAGE Publishers

Nguyen Nhut Xuan Dung 1996  Identification and evaluation of non-cultivated plants used for livestock feed in the Mekong delta of Vietnam. M.Sc. thesis, Swedish University of Agricultural Sciences, Uppsala

Ogle B M, Ho Thi Tuyet, Hoang Nghia Duyet and Nguyen Nhut Xuan Dung 2003 Food, Feed or Medicine: The Multiple Functions of Edible Wild Plants in Vietnam. Economic Botany 57 (1) pp. 103-117

Ogle B M, Ha Thi Anh Dao, G. Mulokozi, and L Hambraeus 2001 Micronutrient composition and nutritional importance of gathered vegetables in Vietnam. International Journal of Food Science and Nutrition 52:485-499 

Received 14 July 2007; Accepted 14 August 2007; Published 4 October 2007

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