Ruminants: fibrous crop residues

Following his review for FAO of fibrous crop residue research (essentially straw treatment) (Jackson, 1978), in 1980 Jackson undertook a consultancy for the Danish International Development Agency-sponsored Integrated Rural Development Project in Noakhali District, Bangladesh. An international seminar entitled "Maximum Livestock production from Minimum Land" was conducted on this occasion and follow-up seminars were held in 1981, 1982 and 1983. Participation was international and the proceedings were published (Jackson et al., 1981, Preston et al., 1982 and Davis et al., 1983). These seminars led to a flurry of coordinated research in Bangladesh, India, Thailand and Sri Lanka, backed up by laboratories in Europe and Australia. The Australian-Asian Fibrous Residues Research Network managed by the University of Melbourne, coordinated research on the subject in Asia by conducting annual meetings in an Asian country from 1981 to 1987, in addition to the Netherlands government-sponsored research and extension projects in Sri Lanka over the same period. From 1985 onwards, an Indo-Dutch project started research on crop residues for a period of ten years. The Project closed in 1995 and has just distributed its last publications (see series edited by Singh and Schiere). The International Rice Research Institute has been coordinating an Asian crop-livestock network (Carangal and Sevilla, 1993) for the past decade.

As a result, Devendra (1991) recorded that 28 meetings had been held on the subject in Asia during the past 17 years. A 1995 update would probably bring the figure in the range of 35 - 40.

Several approaches have been researched and the most promising, from a technical stand-point, are Urea-ammonia treatment, nitrogen supplementation by a urea-molasses block, protein meals, various legumes and luxury feeding (Doyle et al., 1986; Preston and Leng 1987; Owen, 1994; Joshi et al., 1994 and Singh and Schiere,1995).

The uptake of research results has been most widespread in China (Dolberg and Finlayson, 1995). There is recent evidence of an uptake in Bangladesh, associated with the small Grameen Bank-type loans. In addition, the Indian National Dairy Development Board promotes both "bypass" protein and urea-molasses blocks, but in many situations the results were disappointing. Where uptake has taken place, there has been, typically, strong institutional and/or political support. However as weak livestock extension services are common in most Asian countries, this has been a major impediment and explains to a large extent the lack of uptake.

There are two positive outcomes to be noted from the crop residue work. The first is that it has produced a number of well-trained Asian scientists with expert knowledge on fibrous crop residues, all of whom have links to advanced laboratories and know of each other's work.

Provided that the necessary arrangements are in place, such as appropriate budget lines to facilitate linkages between farmers and scientists, it ought to be possible to harvest the fruits of this exercise in scientific capacity-building by involving these scientists in on-farm research.

The second outcome is that technologies are now in place which will enable an increase in large ruminant production without the use of grain (a strong concern regarding the foregoing is expressed in Brown and Kane, 1995), in line with traditional feeding practices in Asia).

Research Features and Results

A typical feature of the research results is that they are only in part discoveries made by scientists. Much can be classified as being documentation of farmer practices. Alkali treatment with urea-ammonia and urea-molasses block work can be classified as scientist- led discoveries, but one important lead from the work has been the potential benefits that may be obtained from pursuing further research in the area of variation in the quantity and quality of fibrous crop residues (papers in Singh and Schiere, 1994 and 1995). The work has also indicated that in intensively cropped areas where there is little access to grazing, cattle have apparently adopted a process of natural selection for high fibrous crop residue intake (Mould et al.,1982 and Chowdhury, personal communication). Indeed, Chowdhury et al., (1995) showed how cattle in Bangladesh gained weight, when fed untreated straw and drank an algae suspension as the only protein source.

Other areas in this field which have received considerable research attention in recent years are (i) the concept of surplus feeding - allowing the animal to select the most nutritious parts, (ii) protein meal or "bypass" protein supplementation and providing a supplement of fibrous crop residues with legumes to stimulate the rumen function (Silva and Orskov, 1985 and Preston and Leng, 1987).

While Preston and Leng (1987) presented the general principles to be followed in nutritional terms for feeding of fibrous crop residues, it can be shown that most of these contain strong elements of traditional farmer practice. Thus, it is a common practice in many countries to allow ruminants to graze cereal fields after harvest; the animals are thus enabled to indulge in selective eating. Likewise, it is common farmer practice in many countries to supplement the intake of stall-fed animals with some high-protein meals and green grass or legumes as an addition to the basal diet of fibrous crop residues.

While the research has focused on a major Asian feed resource (fibrous crop residues), more progress could have been achieved if on-farm trials and farmer participation had played a greater role and the scientists had been more active in dealing with feedback from farmers.

Only in its final years did the Indo-Dutch Project undertake serious on-farm research (Singh and Schiere, 1995), resulting in a much sharper focus and awareness of on-farm feeding constraints and the role of dual-purpose millet in semi-arid regions. In this sense, the project was closed prematurely. There is still much work to be done within an approach which combines farmer practices, on-farm research and - when required - laboratory work.

In January 1995, a five-year participatory project sponsored by the Australian Agency for International Development, entitled 'Forages for Smallholders', commenced operations in Indonesia, Laos, Malaysia, The Philippines, South China, Thailand and Viet Nam. The management of the project rests with the International Centre for Tropical Agriculture (CIAT, a member of the Global Communications for Development Research-CGNET) and the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Monogastrics

The innovative monogastric work on local resources has come from Viet Nam, in projects supported by FAO, the Swedish International Development Cooperation Agency (SIDA) and the Swedish Agency for Research Cooperation with Developing Countries (Preston and Ogle, 1993 and Preston et al., 1994).

The local resource model promoted by these projects was originally developed in Colombia by the NGO CIPAV (Centro para la Investigacion en Sistemas Sostenibles de Produccion Agropecuaria) and is based on the following premises (Preston and Murgueitio, 1992):

• The (humid) tropics have a comparative advantage to use solar energy and highly productive crop plants and trees to convert carbon dioxide into biomass which can be fractioned to satisfy people's requirements for food, fuel, clothes and shelter.
• The integration of crops, trees, animals and recycling of waste.

On-farm trials have been conducted in close cooperation with local chapters of the Women's Union of Viet Nam, since 1992. The Women's Union in Viet Nam plays an important role in providing assistance to improve family welfare, especially in rural areas, and is very active in developing savings and credit schemes to enable rural families to increase their income. This institution has a national membership of more than 8 million people and is represented in almost all hamlets and villages. It has proved to be an effective vehicle for the participatory development and transfer of livestock-based technologies for rural farm families, thus ensuring that the technical research and development work takes place within a relevant socio-economic framework.

Experience so far reveals that the local resource model appears to be of greatest interest to the people in the poorest regions, i.e. Central and North Viet Nam. In these regions, on-farm trials with multipurpose use of sugarcane, involve the following elements: raw juice, which is fed to pigs as a source of energy, and the bagasse which is used as fuel in place of wood. The tops are fed to ruminants and by adding a low-cost (US $ 35) polyethylene tube biodigester to the system, additional fuel is made available to the household, while the slurry can be used in fish ponds, for crops and vegetables, or sold (as seen with the Grameen Bank in Bangladesh).

The elements of this model which have found the widest application are sugarcane juice, as a source of energy to pigs in remote areas, and the polyethylene tube biodigester, which has found application in a variety of situations and countries. From the commencement of on-farm trials in Viet Nam in 1992, there are now 700 of these installed in sites from the Mekong Delta in the South, to intensive livestock units in and around Ho Chi Minh City, to very sandy, upland villages in mid-Viet Nam around Hue and to hilly areas in Cao Bang Province in the North. The digester is also doing well in pilot trials underway in countries such as Cambodia, Bangladesh and United Republic of Tanzania. In all these sites, the farmers pay for the necessary material, indicating their strong interest.

Research has shown that sugarcane juice can be fed, in limited quantities, to egg-laying hens and to ducks, and ongoing research with goat kids shows very promising results when they are fed sugarcane juice as a supplement to suckled milk.

Ongoing long-term research at the Goat and Rabbit Centre of the Viet Namese National Institute for Animal Husbandry is addressing agronomic issues such as row spacing and the effects on soil fertility of allowing dead leaves to remain on the soil etc. Trials have shown that sugarcane produces more biomass than cassava, elephant grass and guinea grass, and that a much larger share can be harvested in the dry season. The net income is also higher (Mui, 1994).

Figure 1 presents information from Hue Province in Central Viet Nam (Lac et al., 1991); it supports the higher yield hypothesis and according to the same report, sugar cane was also the most profitable crop.

The study in Viet Nam explores several other potentially relevant possibilities. One aspect is an innovative approach to post-graduate training, which combines close farmer contact in the research activities with the use of modern means of electronic communication, South-South collaboration and information transfer, which deserve much greater donor awareness and support (section 6).

Most of the monogastric work in Viet Nam was carried out on pigs and, to a much smaller extent, chickens and ducks. However, an interesting institutional model is in place in Bangladesh (described in section 5.1), which involves poultry and caters to poor women.

One very innovative feature of the work undertaken in Viet Nam (in collaboration with other countries as discussed below) is the use of modern electronic communications in post-graduate training, in an effort to respond to criticism of the shortcomings of conventional professionalism (Gupta, 1987; Chambers, 1993 and Pretty, 1995). The conventional system is criticized for being too centralized and standardized, stressing fixed packages. In contrast to the foregoing, the diversity and complexity of climatic zones, farming systems, market access etc., under which small and landless farmers have to operate, demand the services of a professional, with a flexible terms of reference, who will allow designs to evolve and present farmers with baskets of choice in contrast to fixed packages. Networking, exchange of information and the creation of alliances across countries and continents between the comparatively small, but growing number of scientists and students who follow this approach, can be greatly facilitated by modern electronic communication. This has now led to a proposal for an electronic university. The proposal will be discussed in greater detail in section 6.