Livestock Research for Rural Development 9 (2) 1997

Citation of this paper

Protein supplementation of traditional diets for crossbred pigs under village conditions in Central Vietnam


Nguyen Thi Loc, Brian Ogle(1) and Thomas R Preston(2)

College of Agriculture, Hue University, Vietnam
1. Swedish University of Agricultural Sciences, Uppsala, Sweden
2. Finca Ecologica, University of Tropical Agriculture, Thu Duc, Ho Chi Minh City, Vietnam


Availability and price of conventional protein supplements are major constraints to pig production in Vietnam. A survey in two villages in Central Vietnam showed that protein intake is very low in traditional diets (94 - 98 g/pig/day). A feeding trial was carried out in the same two villages to test effects of providing supplementary protein to the traditional diet. Fourteen weaner pigs (Mong Cai x Large White) were fed traditionally, and 12 similar pigs on similar basal diets were given supplements of groundnut cake and fish meal to provide an additional 100 g/day/pig of crude protein. The mean daily live weight gain of pigs under the traditional feeding system was low (202 and 230 g/day in each of the two villages) but was significantly increased to 363 and 366 g/day (P=0.001) by giving the protein supplement. The net economic benefit after deducting the cost of the protein supplement was VND 900/day equivalent to VND 135,000 for the 150 day fattening cycle.

Key words: Pigs, traditional diets, protein supplements


In Vietnam, pig production plays an important role as they are a source of income for the farmer's family and provide manure for the rice and vegetable crops. Compared with other regions of the country, Central Vietnam is one of the poorest due to the severe climate, lack of investment funds and unfavourable natural conditions such as a high frequency of flooding, droughts and storms.

In 1994 there were approximately 4.2 million pigs in Central Vietnam and of these around 2,000 were raised in Binh Dien and Xuan Loc villages, sites that had been chosen for a survey on pig production methods. The main results of the survey were that the level of protein in the traditional diet was very low (Table 1). On the basis of these findings it was decided to carry out an on- farm feeding trial in the same villages to evaluate protein supplementation of the traditional diets.

Materials and methods

On-farm feeding trials were carried out in Xuan Loc and Binh Dien villages from May to October 1995.

Animals, diets and management

The pigs were Mong Cai x Large White crossbreeds, belonging to the farmers. The farmers also provided their normal management, drugs and vaccines. A total of 14 pigs owned by 5 farmer households (2 or 4 pigs on each farm) with initial live weights of 10.7 to 20.0 kg in the two villages (3 farmers in Binh Dien; 2 in Xuan Loc) were fed on a traditional (control) diet consisting of cooked rice, rice bran, cassava meal andvegetable (usually sweet potatoes.vines). Calculated nutrient intake is shown in Table 1. The amounts of the individual feed ingredients varied between farms and also with time, depending on current availability and price. Twelve pigs owned by 6 farmer households (3 in each village) , but of similar genetic background and initial live weight from 9.6 to 23 kg, were fed on the traditional diet supplemented with 190 g/day of groundnut cake (39% N*6.25) and 60 g/day of fish meal (42% N*6.25). It was calculated that the supplement would raise the overall protein supply to 200 g/pig/day.

The pigs were fed three times per day. In the case of the supplementation, the groundnut cake was soaked overnight and then mixed with the boiled basal feed. The fish meal was fed in the morning after being mixed with the rest of the dietary ingredients.

Data collection

The pigs were weighed in the early morning once each month using a 100 kg capacity portable scale with an accuracy of 0.5 kg. Feed intakes were recorded using a 20 kg capacity portable scale. These records were collected every two weeks, and additional random checks were also made. The major feed resources were identified and representative samples were collected and analysed for dry matter (DM), crude protein (N*6.25), crude fibre (CF), ether extract (EE) and ash (AOAC 1985).



Feed intake and growth performance

The traditional pig ration consisted of 48% rice and rice bran; 45% cassava root meal and 7% vegetables (% DM basis). For the pigs from 14 kg to 50 kg, the intakes of the traditional basal diet (as dry matter) ranged from 1.2 to 1.4 kg/pig/day. Calculated metabolizable energy supplied by the diets ranged from 16.0 to 18.4 MJ/pig/day. Protein (N*6.25) concentration ranged from 5 to 7% in the dietary DM, with a total supply of about 80-110 g per pig per day.

The mean values for initial and final live weights and daily gains of the pigs on the traditional and supplemented diets, in each of the villages, are shown in Table 2.

The effects of supplementation and of location (village) are shown in Table 3. There was good agreement between the two villages (292 and 290 g/day live weight gain for the pigs in Xuan Loc and Binh Dien) indicating little difference in the nutritive value of the basal feed resources. Protein supplementation increased live weight gain (adjusted for differences in initial weight) by 83% from 204 to 375 g/day (P=0.001) and final weight from 46 to 68 kg over the 150 days fattening period.

Economic evaluation

The economic results are shown in Table 4. The value of the additional 171 g/day live weight due to supplementation was estimated at VND 1,700 for an additional feed cost of the supplement of VND 800, giving a net benefit of VND 900 per pig per day (VND 135,000 per pig for the total fattening period).


The importance of protein in the system is shown by the low protein content of the traditional diet and the fact that a supplement of around 100 g/day of protein led to an increase in growth rate of 83%, with subsequent economic benefits.

The variation in growth rates of pigs between households is brought to light by doing on-farm trials. This phenomenon is quite common and has been reported previously from Vietnam by Dolberg (1993). The differences are normally ascribed to variations in management practices among households, which may warrant further studies for their precise identification and explanation. In the analysis of the management factor, Ostergaard (1994) points out that the interactions between farm households are an important aspect to consider, as the decisions about the management of biological or financial subsystems are strongly influenced by the social structure of the farm household and the cultural framework in which it exists. In this case, the trial intervention, which consisted of an equal supplement of protein with variation in energy supply between farmers may therefore be an important factor in explaining the differences.

The growth improvement due to protein supplementation in the present trial was similar to that for pigs fed an extra 200 g /day of protein (obtained from 500 g of a 40% protein soya bean meal) on a traditional feeding system in an on-farm experiment carried out in Colombia (Solarte 1994).




The authors gratefully acknowledge the help of the People's Committee and the Women's Union of Binh Dien and Xuan Loc villages, and the Womens Union of Thua thien Hue Province in developing the activities with the farmers at the research sites. The help of the PRA team of Hue University is acknowledged. Thanks are due to the Swedish International Development Agency (SIDA) for providing the financial support that made possible the study.


AOAC 1985 Official methods of analysis. Association of Official Analytical Chemists. 12th edition. Washington, DC.

Dolberg F 1993 Transfer of sustainable technologies in Vietnam. Development of sustainable livestock technologies for ecologically fragile zones in the tropics. Swedish International Development Agency ( SIDA) Stockholm Sweden. Internal Report

Ostergarrd V1994 Livestock systems research-appropriate methods of the future. Integrated livestock/crop production systems in the small scale and communal farming sector. Symposia at the Department of Animal Science, University of Zimbabwe, January 26- 28, 1994

Solarte J 1994 Experiences from two ethnic groups of farmers participating in livestock research in different ecological zones of the Cauca Valley of Colombia. MSc Thesis. Swedish University of Agricultural Sciences. Uppsala

Received 3 May 1997

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