A study of nutrition, performance and economic efficiency of swamp buffaloes in the Mekong delta; literature review  

Pham Tan Nha

Population and distribution of buffaloes

The buffalo population in the world is increasing at about 1.3% annually but the rate of increase of swamp buffalo in Vietnam is slow (0.75%, from 2001 to 2005). At  present, the buffalo population of Vietnam is about 2.9 million heads (Table 1), while the cattle population is  5.54 millions.  Because the buffalo body size is larger than cattle total buffalo meat production contributes more than 50% of total ruminant meat production in the country.

There was a reduction in the population of swamp buffalo from 2000 to 2002 due to a decrease in the grazing land as a result of an increase in the area under cultivation (Table 1). This situation happened in the lowland, particularly in the Mekong and Red river delta provinces where the buffaloes are grazed extensively. However, there has been an increase in numbers in areas, where grazing lands are still available. However, the increase in the growth rate of the buffalo population of Vietnam in the last 5 years was very low (0.75%) when compared with the cattle population (2.8%).

Buffalo populations in different regions of Vietnam and the provinces of the MD are shown in Tables 2 and 3. In Vietnam the overall buffalo population increased by a small amount (0.75% per year from 2001-2005) while it was seriously reduced in the Mekong delta (Table 2). However, there were some signals of recovery of the population from year 2002 to year 2005 in Long An and Kien Giang provinces. At the present time, the provincial governments of Hau Giang, Bac Lieu and Long An provinces have some  programs for buffalo population development.

Feeding and management

In the Mekong Delta, farmers have a long traditional experiences of buffalo raising but techniques are mostly primitive. Management practices are based on extensive systems and buffaloes are freely grazed on natural grass lands, in forests, and on roadsides, canal banks, rice field after harvesting and dikes. . They are usually also fed with rice straw or other crop residues in the dry season and working season. Farmers normally do not fatten buffaloes before selling them for meat. However, there are reports that occasionally buffaloes are fattened  by feeding good quality grass and supplementing with concentrates before sale. Buffaloes are mainly slaughtered when they are not able to work due to old age or as a result of accidents. Housing for buffaloes is simple and often made by local materials such as wood or bamboo with  palm leaf roof in the mountain area, but in the plain area the housing for buffalo is better with concrete floor and brick wall and tile roof . 

After harvesting, farmers in most areas let their buffalo free to take care of themselves in the natural grazing areas. However,  in irrigated areas, farmers have to look after their animals everyday. Grazing of buffaloes is usually the task of children and the older family members who can not work hard.

The importance of buffaloes in small-holder farming systems

Most Asian countries are agrarian, with 60-80% of the population engaged in farm operations in one way or another. Livestock has been an integral component of traditional agriculture for many centuries in Asia (Nanda and Nakao, 2003). Livestock production is firmly based in the smallholder farmers in both the Mekong Corridor and the Sloping Lands. Nationally, about 30% of cash income from agriculture was derived from livestock in 1997/98. In general, the importance of livestock as a source of cash income is highest in upland areas with poor access to markets where villages have to carry goods over long distances to markets. This limits options to crop with a high value per unit weight and livestock such as buffaloes and cattle that can be walked to markets (ILRI, 2002). Livestock provides many on-farm benefits; they are also a source of savings to be sold when cash is needed. Only when households accumulate enough livestock to feel financially secure are they able to make long-term investments in their farming and livelihood systems (e.g. sending children to high school, planting fruit trees, buying a two-wheel tractor or micro rice mill), buffalo play a pivotal role in the overall social development of small farmers. It is the main source of draft power to cultivate crops and prepare paddy rice fields, the main fertilizer and meat-milk supply for small farmers in mountainous area (Tuyen and Ly, 2001).

Supply of meat and milk

Buffalo meat has a lower content of saturated fat than beef and pork, and 40% less cholesterol, 55% less calories, 11% more protein and 10% more minerals as compared to bovine meat, and therefore, it is healthier. The quality has been markedly improved with the crossbred in Australia, which it is hoped will be the future standard in the 'Tender buff program' which has gained much popularity in recent years (Lemcke, 1997). Buffalo milk is healthier, because it is richer in saturated fatty acids. It is high in total solids (18-23%), that make it useful to make into cheese, butter fat, and several kinds of traditional sweets and ice creams. Swamp buffalo milk has even higher fat (9-15%), protein (7.1%), lactose (4.90%) and ash (0.89%) according to work by Thac (1979). Riverine buffaloes produce more milk than swamp buffaloes. The average lactation yield in the best known dairy buffalo breeds, Murrah and Nili-ravi, is around 2000 L (Agarwal and Tomar, 1998). Elite buffaloes with up to 6000 L also exist in India, Italy and Pakistan; this indicates their great potential for milk production. Working swamp buffalo produce 1.94 kg/day in Thailand (Khajarern and Khajarern, 1990) and 1.55 kg/day in Vietnam (Thu, 1997) while a non-working swamp buffalo may yield 2.15 kg/day (Gongzhen, 1996), and crossed with Murrah can yield of 3.73 kg/day in 277 days lactation.

Advantage of draft power and manure

Using buffalo for ploughing is definitely cost efficient in rain-fed lowland mixed farming systems (Bunyavejchewin et al., 1994). Based on profits produced over the investment, a pair of buffalo is 2.6 times more efficient than a tractor (Thu et al., 1995). Advantages include fuel savings, low maintenance costs, high resale value, use of otherwise useless crop residues, reduced dependence on external inputs and solidarity with sustainability. Also, buffalo values increase over the years and they need no costly fuel, maintenance, and they reproduce (FAO, 2000). Comparatively, machines require considerable monetary investment and are usually much larger in size than required by a peasant (Chantalakhana, 2001). Buffalo for work can start at approximately 2 years of age or at 250 kg bodyweight. Young buffalo can pull an approximately 50-80 kg plank or log in a plowed field together with a trained buffalo. They are subjected to work for approximately 1 h per day, gradually increasing to 3-4 h daily. The average buffalo learns to obey commands within 3-4 weeks (Saadullah, 1998). The power and efficiency of animals is increased with age and gain in bodyweight. Buffaloes normally carry up to a 2.0 t load, but can pull more than six times their own bodyweight continuously for 2-3 h, totaling 5-6 h daily in summer and 6-8 h in winter (Acharya, 1988).The average buffalo works up to the age of approximately 11 years. In Thailand, buffaloes work on average 5 h per day for up to 146 days per year. Draft buffalo work approximately 109 days/year in Vietnam (Sanh et al., 1995). In China, one buffalo is sufficient to do all the work on 2-3 hectares of cultivated land. Swamp buffalo plow 0.30 ha/pair per day and harrow 0.73 ha/pair per day (Thu et al., 1995). 

Buffalo manure is an excellent source of nutrients for crops. Approximately 40% of the value of an animal could be in the manure it produces (Hoffmann, 1999). An adult buffalo produces 4-6 tonnes of wet manure per year. Normally, dung is heaped to mature for a few months and spread onto fields to maintain soil fertility. Farmers in South-East Asia spread it in the early rainy season and plow down before planting rice (Devendra and Pezo, 2002).

Hire of buffalo for  draught power and the tractor

The buffalo farms in Tra Vinh province had no income at all from the hire of buffalo for draught power. This is because the tractor manages all different types of fieldwork in the dryer upland environment, and demand for the buffalo thus is lower. Farms in the lowland areas reported an average income of $800 per buffalo per year for hire to other farmers, mainly for transporting rice. The price for fieldwork depends on the current price of rice, and the hire is often paid in rice. The rice is pulled on sledges or barges by a single buffalo (91 per cent), with loads of up to 650 kg at one time. One buffalo may transport rice from around 50 hectare per year, or around 300 tonnes of rice. The transport can involve the whole rice crop to the threshing machine, or the threshed rice for storage in the farmhouse, or rice to the road or canal for further transportation. The farmers often store the rice in their houses waiting for prices to increase. The competitor for buffalo draught power transporting rice is not so much the tractor as human labour. Rice-field workers are hired, and provide flexible labour that can move easily in the fields and do work such as harvesting, transplanting, pulling weeds and carrying sacks of rice on their back. However, when humans carry rice it is often because of a shortage of working buffaloes. Leveling of the rice field after ploughing (Photo 1) is also very profitable work for buffaloes with a reported daily income of between $10-20 one animal.

The most common tractor in question was a two wheeler with handlebar, driven by a noisy, smoking and vibrating diesel engine. The farmers working with tractors in the study all complained about associated health problems. The  two-wheel tractor drives a cultivator aggregate rather than pulling a plough. A new tractor costs around $1200 together with a barge for moving it on the waterways. The yearly net profit from hire was reported to be at around $400. The investment mostly depended on having a supply of customers to work for. Depending on type of soil and degree of wetness condition, a new tractor could plough around two hectares per day, compared to a pair of buffaloes that can plough around 0.3 hectare per day. The ploughing is reported to cost the same, whether carried out by buffalo or by tractor. Careful planning is needed with three rice crops per year and there was a need for the faster tillage supplied by the tractor. This created a high demand for tractor work and many farmers have therefore sold their buffaloes and bought a tractor, or alternatively just hired a tractor for doing the field work. However, because of the wet conditions in the MD, the tractor is reported to work efficiently only for about three years.

All farmers with knowledge of tractors reported that the efficiency decreased after 3 years, together with the reliability. Breakdowns are common, and are also expensive to repair. The costs and time spent on repairs, transport and maintenance then increase and the customers often abandon the hire of an old tractor for a more reliable model. After 8 to 10 years the tractor might be totally worn out and the farmer often had no capital for investment in a new one, or money to buy buffaloes. This result might be that the farmer stops using the tractor to work his own fields and instead hires all the draught power needed. Large numbers of tractors have recently been sold, and the competition between tractor owners for customers is hard. Reduction in prices for the hire of tractors was reported. To move the tractor from field to field on the waterways was more difficult than to move buffaloes. The overall result showed that economic efficiency was better for buffalo compared to tractor about a factor of 2.

Comparative characteristics of the physiology of digestion and nutrition of buffalo and cattle

As with other ruminants, the buffalo has a remarkable ability to refine coarse roughages through rumen fermentation, leading to the formation and utilization of various essential metabolites for its nourishment. Anatomically, the rumen and reticulum of the buffalo are similar to those of cattle. However, the rumen of the buffalo, accounting for over 80 percent of the stomach capacity, is heavier than that of cattle and is 5–10 percent more capacious (Sengar and Singh, 1969). The buffalo omasum has lower tissue weight and capacity but the same number of laminae, having a narrower inter-laminar space than cattle. The abomasum of buffalo differs slightly in the distribution of cellular elements in the mucosa and its digestive ability is adversely affected by high air temperature than in the case of cattle (Chalmers, 1974). With respect to comparative physiology of digestion of buffalo and cattle, Chalmers (1974) reported that, based on results from several studies, agreement had been reached that::

·         the rumen of the buffalo calf becomes functional at an earlier age;

·         the microbial populations, bacteria and protozoa, are more numerous in the buffalo rumen;

·         the changes in the microbial populations, as affected by changes in season and thus proportions of food constituents, are more marked in the buffalo rumen;

·         the rate of passage of feed through the rumen of the buffalo is slower, allowing a longer retention time and exposure to more microbial action;

·         ammonia and soluble nitrogen disappear from the rumen fluid of buffalo more rapidly than from that of cattle, suggesting that the former utilizes protein more efficiently than the latter.

All of these characteristics tend to indicate that buffaloes have a higher efficiency of digestion than do the cattle. In his review of research results, derived from a large number of studies in the Indian subcontinent, Gupta (1988) concluded that buffaloes were more efficient converters of coarse roughages than cattle. His conclusion has been substantiated by the results of a number of trials which have shown higher concentrations of some metabolites in the rumen of the buffalo and higher digestibilities of dry matter, organic matter and crude fibre when compared to cattle. However, contradictory findings have also been regularly reported by a number of researchers such as Moran (1983). Chalmers (1974) expressed her doubts on such claims due to the facts that

·         a number of trials were involved with inadequate numbers of experimental animals;

·         studies should take into account differences in the kind of feeds, feeding levels, age and type of animals, rumen volume, rate of passage of feed, adequacy of water supply, deficiencies of vital feed constituents, management practices and so forth;

·         rumen content of various metabolites is always dynamic, with synthesis and brea