Feeding pigs by sugarcane juice and introducing biodigesters to small scale farmers in Caobang province

Mai Van Sanh, Vien Thi La¹, Le Viet Ly and T R Preston²

National Institute of Animal Husbandry, Hanoi, Vietnam

Abstract

This study aimed to introduce new techniques of using sugarcane juice for feeding growing pigs and producing biogas for cooking by installing biodigesters using local low cost material (tubular polyethylene film) in selected small farm households in Caobang province in the North of Vietnam.

Four groups of farmers (45 in total) participated in the demonstrations which were initiated at different times in adjacent areas close to the town of Cao Bang. The pigs were fed the traditional diet together with a supplement of one litre per pig per day of fresh sugar cane juice. Low cost plastic biodigesters were installed on five of the farms.

The pigs had a good growth rate of 398–453 g/day at an estimated cost of 9.6 litres of juice (20 kg cane stalk) for each additional 1 kg of liveweight gain. The gain in income of the farmers was estimated to be of the order of 12,000–18,000 VND/month per pig with a reduction in raising time of about one month.

The low cost plastic biodigesters worked well with only a slight reduction in gas production in the winter months. The technology appears to be suitable for application in mountainous areas in North Vietnam.

Key words: Caobang province, mountainous areas, sugar cane juice, pigs, biodigesters, small scale farmers

¹ Women Union of Caobang Province
² Finca Ecologica University of Agriculture and Forestry, Thu duc District, Ho Chi Minh City
E-mail: thomas%preston%sarec%[email protected]

Introduction

General situation

Caobang is a mountainous province in the North of Vietnam. The population is about 600,000 inhabitants, and comprises 14 ethnic groups, most of them being minority people. The natural area is 845 km², of which 93% are mountains and hills, so the area of arable land is small.

There are about one hundred thousand peasant families in the province and 65% of the agricultural labourers are women. They depend on the cultivation of rice, maize and cassava in the small valleys and sloping hills. The agricultural production system is extensive and most of the agricultural products are used for home consumption. Average annual income per capita of the province is 81 USD, but it is only about 40–50 USD for the peasants. It is estimated that annually there are 20–30% of the peasants who do not have sufficient food.

Animal production

Caobang has good conditions for buffalo and cattle production with large grazing areas and available natural feed resources. The population of buffalo is about 130, 000 and of cattle about 100, 000. As there are food shortages for people, there is also a lack of feed for pigs which traditionally are fed mainly on rice bran, maize, vegetables and kitchen waste.

Some data from an investigation of growing crossbred pigs (Women's Union of Caobang, unpublished data) showed that:

• Average initial weight was 15 kg.
• Average weight gain was 10 kg/month.
• Average duration of raising was 6 months.
• Average slaughter weight at 8 months of age was 75 kg.

From 1992, the technique of sugarcane juice feeding for pigs (Sarria et al 1991) and the installation of low cost biodigesters (Bui Xuan An et al 1994), has been introduced in Tuyen Quang province (Oanh 1994) and later in Bac Thai province (Hoang Thi Tham et al 1997). Many experiments were conducted in Hue, Ho Chi Minh City and Cantho provinces to estimate the growth rate of pigs and the economic efficiency on this feeding system (Bui Huy Nhu Phuc et al 1994; Nguyen thi Loc et al 1994; Bui Hong Van et al 1994). The productive parameters were comparable with those for industrial-type diets but the adoption by farmers was a function of relative prices and market opportunities for the sugar cane. Communities in mountainous and hilly areas were generally those which adopted most readily the technology (Le Viet Ly and Luu Trong Hieu 1994).

Objectives

This study aimed to introduce the techniques of using sugarcane juice for feeding growing pigs and producing biogas for cooking by installing biodigesters using local low cost material (tubular polyethylene film).

Hypothesis

The following hypotheses were tested:

• Use of sugarcane juice for feeding growing pigs will increase daily weight gain, reduce raising time and contribute to improved income of farmers.
• Use of manure from animal production to produce biogas for cooking with local low cost materials will decrease expenditure for fuel in the family and contribute to protection of the environment.

The activities

Farmer training

The farmers in the project are Tay, Nung and Kinh people. They plant sugar cane mainly for making “brown” sugar at household level and they raise some pigs by the traditional way. Biomass for fuel is in short supply and most families have to travel long distances to the forest to collect firewood. The work is hard and takes much time normally being done by the women.

A training course was organized for farmers and assistants from the Women's Union to introduce the techniques of using sugarcane juice for pigs and producing biogas with a low cost plastic tube. The content of the training course included demonstrations at farm family level. After the training course, farmers quickly improved their understanding of the new systems and how to apply them.

Sugarcane juice feeding pigs

Up to now, 45 farmers have been using sugarcane juice for feeding to growing-fattening pigs. A total of 131 crossbred pigs (Large WhiteXMong cai) were in the project. Based on experience from the introduction of sugar cane juice feeding in Tuyen Quang and Bac Thai provinces, it was decided to use the juice as a supplement to the traditional diet.

Installing biodigesters

Five families in the project were selected for installing biodigesters. All of these farmers had buffaloes or cattle and pigs. The farmers were trained in the technique of installation and use of biogas for cooking. During the demonstrations, the farmers and assistants from the Women's Union participated actively in the work of installation. Details were written in simple “handouts” of the process of charging the biodigesters with the appropriate amounts of manure and water.

Results and discussion

Use of sugarcane juice for feeding to growing pigs

Four groups of farmers (45 in total) participated in the demonstrations which were initiated at different times in adjacent areas close to the town of Cao Bang. The pigs were fed the traditional diet together with a supplement of one litre per pig per day of fresh sugar cane juice. The basal diet was first cooked on an open fire and then the sugar cane juice was added before feeding. The weights of the pigs were measured with a “balance” weigh scale which is the traditional way of determining liveweight prior to selling for slaughter.

The four groups of farmer raised the pigs in different seasons around the year. The growth rates ranged from 12 to 14 kg per month (400–450 g/day) which the farmers considered to be above average for traditional diets (9 to 10 kg/month).

Table 1: Means for initial and final weights and daily weight gain of growing pigs fed traditional diets supplemented with sugarcane juice

Nguyen Thi Loc et al (1994) used sugarcane juice and protein supplement to feed crossbred pigs (Mong Cai x Cornwall) in Hue and recorded a daily weight gain of 436–479 g/day. In an experiment on crossbred pigs (Baxuyen x Landrace) in Cantho, pigs were fed by raw sugar and water spinach (Bui Hong Van et al 1994) with a daily weight gain of 398 g/day. With different levels of soya bean protein in a diet based on diluted raw sugar (reconstituted cane juice) for crossbred Yorkshire x Landrace x Derek pigs, Bui Huy Nhu Phuc et al (1994) obtained weight gains of 539–691 g/day.

In contrast with the results cited above, in the demonstration in Cao Bang, the sugar cane juice was used in small quantities as a supplement and not as the basal diet. However, the farmers in Cao Bang considered that this was the best way to use the sugar cane juice and were well satisfied with the results.

Economic estimation

Data on the performance of pigs fed on the traditional system were collected from participating farmers and their neighbours. It appeared (Table 2) that supplementation with sugar cane juice resulted in better growth rates, one reason for which may have been the palatability of the sugar cane juice stimulating the pigs to increase their intake of the basal diet.

Table 2: Comparison of economic efficiency between two feeding systems: traditional diets with and without sugarcane juice (SCJ)

* Data for pigs fed traditionally collected from informal surveys of the farmers

An increase in slaughter weight of 6.2 kg and a reduced raising time of 37 days are important economic advantages. A conversion of 9.6 litres of juice for every additional 1 kg of weight gain was also considered to be economically attractive. This amount of juice required about 20 kg of sugar cane stalk which at a market price of 300–400 VND/kg and with pig liveweight at 12,000 VND/kg, resulted in an added benefit of 4,000–6,000 VND/kg of pig liveweight or 12,000–18,000 VND/month per head.

Biogas

The five biodigesters which were installed are all working well. The price was reasonable taking into account the economic conditions of the farmer. The gas production was reduced slightly by the low temperature in winter, but this was not a serious problem. The positive experience indicated that this technology can be applied in the mountainous areas.

Conclusions

• Pigs fed at household level in Cao Bang province on traditional diets supplemented with 1 litre/head/day of fresh sugar cane juice had a good growth rate of 398–453 g/day at an estimated cost of 9.6 litres of juice (20 kg came stalk) for each additional 1 kg of liveweight gain.
• The gain in income of the farmers was estimated to be of the order of 12,000–18,000 VND/month per pig with a reduction in raising time of about one month.
• The low cost plastic biodigester appears to be a suitable technology for application in mountainous areas in North Vietnam.

Acknowledgments

This study was supported financially by the SIDA MSc programme on ‘Livestock-based Systems for Sustainable Use of Natural Resources’.

References

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