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MEKARN Regional Conference 2007: Matching Livestock Systems with Available Resources |
The prevalence, usages and nutritional components of the available local green plants in the Mekong Delta of Vietnam have been estimated, because of the concern about the ecological balance and the need to identify their valuable traits. In this study, the main interest is in their nutritional values as potential sources of feed for live stock.
The two vegetable herbs Rau Dua (Ludwidgia adscendens) and Rau Sam (Portulaca oleracea) were studied in the natural condition and also when cultivated. They were then tested as component of the feed for pigs on the University farm. Rau Dua (RD) with two ecotypes (RD do, RD xanh) and Rau Sam (RS) were studied for biomass yield and chemical composition when grown in three different soils (alluvium-high land, alluvium and brackish water).
In the natural condition, the biomass and nutritive values of both ecotypes of Ludwidgia adscendens and also of Portulaca oleracea were higher in the alluvial areas. Crude protein and crude fibre were 19.5 and 7.6 % (in DM), respectively for Ludwidgia adscendens and 20.7 and 9.3 %, respectively for Portulaca oleracea. When grown in ponds fertilized with pig manure, the fresh biomass yield for Ludwidgia adscendens was 19.7 tonnes/ha and 1.9 tonnes/ha as DM. The contents in DM basis of CP, EE, CF and ash were 23.2, 4.9, 6.2 and 10.7%, respectively. The average fresh biomass yield of Portulaca oleracea, grown on soil fertilized by pig manure was 4.40 tonnes/ha and 0.40 tonnes/ha as DM. CP, EE, CF and ash were 22.4, 5.5, 9.7 and 19.1% in DM, respectively. When offered as supplements to sows, intakes were 2.0 and 1.7 kg/day for Ludwidgia adscendens and Portulaca oleracea. Comparable data for growing pigs were 1.3 and 1.0 kg/day.
The Mekong Delta is one of two major rice bowls of Vietnam (Thong 1995). The region has equal four million hectares of land for rice cultivation, and harvests 17.5 million tonnes of paddy rice, which accounted for 51% of the total production of the country (Statistical data of Agriculture, Forestry and Fishery 2003). Moreover, various rice-based farming systems, involving aquaculture, animal husbandry, cash crops and fruit cultivation, are being sustained by small scale farmers, have been dominant in the region, and these farming systems were proven to be more profitable than rice alone (Vo Tong Xuan 1999). Therefore, the increase of usage of low utilized local feed resources is expected. The green plants, including many species and varieties, are the one of the major source of expected feed resources, especially vegetables that are readily available and consumed by humans and/or animals in the Mekong Delta (Ogle et al. 2001). They are highly productive sources of protein-rich biomass and are ideal complements for low fibre basal diets in animal feeding systems (Preston 1995).
Rau Dua (Ludwidgia adscendens) is an annual vegetable herb. It is creeping and floating on the water surface in the rural area. Its stem is slender, rooting at the nodes and leaves alternate, and flowers are white. The extract of whole herb cures fever, hermaturia or hermorrhagic dysentery (Dan and Nhu 1990). The vegetable samples contain the nutritional values of dry matter (13.8 %), and in the DM, CP (22.4 %), EE (5.2 %) and Ash (9.8 %). It is often applied in pig diet by farmers in the Mekong Delta (Xuan Dung 2001).
Rau Sam (Portulaca oleracea) is an annual herb found in wet places. Its’ stems are succulent, reddish and leaves fleshy, glarous with yellow flowers in terminal cluster. The whole plant contains carotene, vitamins (C, B1, B2, and PP), minerals (Ca, Mg, Na, and K), nicotinic acid and liquiritin. Its extract is used against bacillary dysentery and to control mastitis (Dan and Nhu 1990). It could be a good feed source for animals, especially for pig feeding. The crude protein content in the herb is as high as 24.5% in DM basis (Xuan Dung 2001), with 0.8 % Ca and 0.5 % P (Tuan Hung 2004).
1. Promoting the well prevalence in the different soil areas to supply a high fresh biomass and nutritive values in the natural
collection.
2. Can grow well on the water or soil fertilizer by pig manure compost to produce a high fresh yield and nutritional values in
cultivation.
A field study was implemented in three different soil areas (1) high land alluvium (An Phu and Cho Moi districts, Angiang province) (2) low land alluvium (O Mon district, Cantho City and Binh Minh of Vinhlong province) and (3) the brackick water (Vi Thuy and Thanh Tri districts, Soctrang province). A semi-structured questionaire was used as a tool in a rapid apprasal (Freudenberger 1994). Thirty samples of the two species of Rau Dua and Rau Sam were collected and measured the fresh biomass based on the vegetation cover equal 5 m2 per site by frames (1 m2 per one). Samples of each were taken and the contents of DM analysed by micro-wave radiation (Undersander et al 1993); CP, CF, EE were analyzed according to AOAC (2000).
The trial was conducted in Can Tho uni. area with 240 m2 of water surface divided into 3 parts for growing RDxanh from rooty stems in row spacing 3-4 cm. As an area 60 m2 of sandy soil divided into 4 plots for planting RS from rooty stems in row, spacing 3-4 cm. The fertilizer used was pig manure compost. The fresh biomass of two spieces was harvested after 40 days for cycle. The whole plants were measured and the content of DM, CP, CF, EE and ash (Undersander et al 1993; AOAC 2000). Two Yorkshire dry sows and 7 growing pigs were used for testing favourite to RDxanh and RS.
Data were analyzed by using the Basic statistics and General Linear Model of Minitab Statistical Software version 13. Sources of variation were treatments and blocks. The Tukey Test for paired comparisons was used to separate means when the differences were significant at the 5% level.
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Table 1. Biomass yield and chemical composition of Rau Dua (Ludwidgia adscendens) collected in three different soil types of the Mekoong Delte, Vietnam |
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Times |
Types |
SEM |
P |
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Allu-High land |
Alluvium |
Brackick water |
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Fresh biomass (tonnes/ha) |
13.83b |
15.00b |
11.58a |
0.585 |
0.001 |
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DM, % in fresh |
10.63ab |
11.15b |
10.24a |
0.222 |
0.014 |
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CP, % in DM |
19.97b |
19.54b |
13.68a |
0.924 |
0.001 |
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CF, % in DM |
7.44 |
7.65 |
7.20 |
0.276 |
0.481 |
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EE, % in DM |
4.39a |
4.79b |
4.10a |
0.100 |
0.001 |
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Ash, % in DM |
9.48 |
9.76 |
9.87 |
0.210 |
0.462 |
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Table 2. Biomass yield and chemical composition of Rau Sam (Portulaca oleracea) collected in three different soil types of the Mekoong Delte, Vietnam |
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Times |
Types |
SEM |
P |
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Allu-High land |
Alluvium |
Brackick water |
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Fresh biomass (tonnes/ha) |
5.75 |
5.03 |
5.00 |
0.255 |
0.060 |
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DM, % in fresh |
7.80b |
7.83b |
5.70a |
0.214 |
0.001 |
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CP, % in DM |
20.71 |
20.72 |
20.52 |
0.718 |
0.967 |
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CF, % in DM |
8.59b |
9.33a |
9.33a |
0.220 |
0.014 |
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EE, % in DM |
4.03c |
5.16b |
4.73a |
0.123 |
0.001 |
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Ash, % in DM |
22.34a |
18.86b |
20.50a |
0.210 |
0.001 |
In the natural condition, the biomass and nutritional componets of both ecotypes of Ludwidgia adscendens and also of Portulaca oleracea were higher in the alluvial areas. Crude protein and crude fibre were 19.5 and 7.6 % (in DM), respectively for Ludwidgia adscendens and 20.7 and 9.3 %, respectively for Portulaca oleracea (Tables 1 and 2).
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Table 3. Biomass yield and chemical composition of Rua Dua (Ludwidigia adscendens) cultivated on water surface in Cantho area |
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Items |
Mean±SD |
Min |
Max |
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Fresh biomass (tonnes/ha) |
19.70 ± 1.09 |
18.50 |
20.67 |
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DM, % in fresh |
9.44 ± 0.01 |
9.43 |
9.46 |
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CP, % in DM |
23.17 ± 0.61 |
22.31 |
23.76 |
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CF, % in DM |
6.19 ± 0.12 |
6.01 |
6.28 |
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EE, % in DM |
4.89 ± 0.30 |
4.60 |
5.29 |
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Ash, % in DM |
10.67 ± 0.55 |
10.07 |
11.27 |
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Table 4. Biomass yield and chemical composition of the Rua Sam (Portulaca oleraced) cultivated on sandy soil in Cantho area |
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Items |
Mean ± SD |
Min |
Max |
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Fresh biomass (tonnes/ha) |
4.67 ± 0.29 |
4.5 |
5.0 |
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DM, % in fresh |
7.75 ± 0.00 |
7.75 |
7.75 |
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CP, % in DM |
22.38 ± 0.00 |
22.37 |
22.38 |
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CF, % in DM |
9.72 ± 0.00 |
9.72 |
9.73 |
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EE, % in DM |
5.47 ± 0.00 |
5.47 |
5.47 |
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Ash, % in DM |
19.15 ± 0.00 |
19.13 |
19.15 |
When grown in ponds fertilized with pig manure, the fresh biomass yield for Ludwidgia adscendens was 19.7 tonnes/ha and 1.9 tonnes/ha as DM. The contents in DM basis of CP, EE, CF and ash were 23.2, 4.9, 6.2 and 10.7%, respectively. The average fresh biomass yield of Portulaca oleracea, grown on soil fertilized by pig manure was 4.70 tonnes/ha and 0.40 tonnes/ha as DM. CP, EE, CF and ash were 22.4, 5.5, 9.7 and 19.1% in DM, respectively (Tables 3 & 4). RD was also higher biomass yield than RS in both natural and cultivated condition.
When offer two species as supplement to sows based on 2.0 kg concentrate, the intakes in fresh were 2.0 and 1.7 kg/day for Ludwidgia adscendens and Portulaca oleracea. Comparable data for growing pigs based on 1.0 kg concentrate were 1.3 and 1.0 kg/day.
· It is suggested that Portulaca oleracea with lower biomass, higher nutrients in cultivation. Need to test for the traditional treatment.
· Ludwidgia adscendens high biomas and nutrients could cultivate well as supplements for pigs, using effectively animal waste residues, keeping environment and biodiversity issue.
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