36 Plenary 4
Contrast Between Developed And Developing Countries With Emphasis
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to avoid the pollution they can cause. Moreover, animal production is reverting gradually to less intensive systems.
The emphasis on crop monoculture became supported by techniques to sustain it as long as possible. Crop varieties were selected for the main product only, with less emphasis on the value of crop by-products as animal feed. Despite this, it was for example, shown that the quality of straw had no relationship to quantity and quality of grain in work by (Tuah et al., 1986.) However if grain yield is reduced due to draught or disease the quality of straw is generally increased due to lack of transfer of sugar to the grain.
Varieties that could respond to very high levels of fertilizer were, and still are, chosen.
Herbicides became a part of normal crop husbandry, rejecting the previous retention of crop rotations to achieve some control of weeds. The same crops could be grown year after year provided they were supported by large amounts of herbicides. This aspect has recently been furthered by the introduction of herbicide resistant genetically modified crops (GM), using the herbicide ―Roundup‖. This approach is receiving some adverse criticism as it is, as yet, inadequately researched for many systems. The effect of feeding GM crops is being critically assessed, particularly in Europe.
Another serious aspect of the highly mechanized monoculture was examined by Blaxter (1989). It was Kenneth Blaxter who calculated that each calorie digested had to be supported by 10 calories of support energy in the form of fossil fuel used in cultivation, sowing, fertilizer, herbicides, harvesting, drying, food processing, transport and waste disposal. This aspect has serious consequences for global warming and even for those countries that have signed the Kyoto agreement to reduce fossil fuel consumption (the USA has not signed). Another serious aspect of mechanized and herbicide-controlled monoculture has been soil fertility and, even more, biodiversity. Birds surviving on weeds are being severely affected (Clerkin 2002). Many bird species that were previously prevalent are now seriously endangered and many have disappeared altogether.
Situation in most so-called developing countries
I will now turn attention to the situation as seen in most developing countries particularly densely populated areas in Asia and Africa. Here in the main, farm animals are multipurpose i.e. they serve several functions such as draught power, security, meat, milk and manure production and they are seen to be in a positive interaction with plants and soils. Crops are regularly rotated and often several complementary crops are grown together.
Multicropping
While appropriate crop rotations in Europe were recognized to support good soil fertility and weed control, growing crops together was less common, but often seen in densely populated areas. In developing countries crops, such as cassava, normally harvested once/year are grown together with legumes e.g. groundnut and soyabeans and even with maize. The leguminous crop, no doubt, contributes to the soil‘s nitrogen economy. These systems with different harvesting times are labour consuming, but as labour is generally not scarce, labour saving devices provide no solution. A herbicide resistant monoculture, is certainly no solution. Such systems are also useful for soil fertility. In many areas leguminous trees e.g.
Sesbania, Glyricidia and Leucaena are grown on the edges of roads and on edges between small fields of rice. These trees have several functions. They accumulate N, and are thus likely to benefit the crops. Their branches are widely used as fodder for sheep and goats in the dry season, the wood is used for domestic fuel and other purposes and their roots contribute to soil stability and N fertility.
38 Animals in agro-forestry
Grazing under coconut trees
Animals grazing under trees are of frequent occurrence, although such animals are thought by many to damage forests, mainly through browsing on the trees themselves. Seldom have measurements been made. I became involved in a joint project on grazing within coconut plantations.
This was a joint project with the Coconut Research Institute in Lunawila. Large areas of Sri Lanka are covered with coconut plantations owned, both by large industries and by small farmers. Coconut trees do not form a dense canopy so it is always possible to grow other plants under the trees. In many instances cattle are seen grazing under the coconut trees.
Here it is often the case that the owners of the coconut trees are not the owners of the cattle.
Cattle are owned by small poor farmers and usually the owner of the coconut trees lets them graze at no cost. An experiment was set up to graze cattle under the coconut at a high stocking rate. In fact, the animals were having much less food than they needed for maximum growth and reproduction.
The results are given in Table 1 from Pathirana et al., (1996) and Ørskov (2002). The animals were old at calving, calving interval was long and milk yield was low.
Supplementing with imported rice straw improved the animals‘ reproductive performance and if they were also given rice bran performance was further increased so that the calving interval was then normal at 13 months.
Table 1. Effect of grazing and supplementation on coconut yield, animal production and soil water holding capacity for six seasons (Pathirana et al., 1996; Ørskov 2002) measured.
Treatment Coconut Yield Nuts/palm
Copra kg/palm
Calves/
Animal
Lactation kg
Lactation days
Water- holding Capacity
0-10cm mm/m
UG 41.1 11.1 - - - 16.9
G 47.9 13.3 0.3 181 201 18.3
GS 50.6 14.1 0.6 405 264 18.9
GSS 57.4 16.7 0.9 664 282 17.6
SEM 2.0 0.5 0.03 25 4 -
UG, un-grazed; G, grazed; GS, grazed and supplemented with rice straw; GSS, grazed and supplemented with rice straw and rice bran; SEM, standard error of the mean.
Just grazing increased coconut yield by about 15%. No wonder the owners of the coconut trees encouraged the small farmers to graze their animals under the trees! The increased yield probably owed to a rapid turnover of biomass and to the effect on soil quality, recorded here as water holding capacity.
Grazing under oil palms
The contribution to the socio-economy of a region became very apparent to me recently on a visit to an oil palm plantation in Bengkulu province of Sumatra, Indonesia. The Indonesian company owning the plantations employed workers to collect palm fruit bundles from the plantation and carry them to a road passable by trucks. The employers had taken the initiative to give each worker one Bali beast (Bos banteng), for pulling a small cart. This could hold about 15 to 20 bundles, instead of the one carried by the worker, and it increased the capacity
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of the worker to attend to 15 ha rather than 10 ha. The feed for the cattle was plants growing under the trees plus leaves and core from the palm fronds which had to be cut down before cutting of the palm bundle. At night the cattle were also given some palm sludge from the factory. It soon became apparent that there was much more feed than one animal could eat so the farm workers were allowed to take several animals with them to the plantation during the working day. At present an average of 6 animals accompany each worker in the morning.
What is the possible stocking rate under palm oil trees? I was told approximately 2/ha, even with a full canopy. If this is so, many millions of cattle could be fed under oil palm trees in the world. This procedure could provide a secure living for many families. Similar effects on oil palm production were observed some years ago, to which reference is made recently (Devendra 2004; Table 2).
Table 2. Effect of mixed cattle and goat grazing on annual yield of fresh fruits in oil-palm plantations, Malaysia (Devendra 2004). (Fresh fruit bundles, 1000 kg./ha)
Year Grazed area Non-grazed area Difference
1980 30.55 (C)* 25.61 4.94
1981 17.69 (C)* 15.87 1.82
1982 25.12 (C & G) 22.97 2.15
1983 23.45 (C & G) 18.29 5.16
*C = cattle: C & G = cattle and goats.
Here there were consistent increases in oil palm yield of some 15 to 20%, as a result of grazing with cattle and goats in the plantation. This probably resulted from an increased rate of biomass turnover and possibly also from increased soil water holding capacity. The positive effects of agro-forestry with animals are not unique to tropical areas. Recent work reported by Sibbald (1999) and Sibbald et al., (1991) showed that productivity of sheep grazing under trees was similar to, and in dry years, greater than that of sheep grazing a similar area in open land. In the forest areas Sycamore trees were grown. Clearly this would not be so if there were complete canopy by the trees. It will also depend on the type of animals. In the work of Sibbald the animals were ruminants.
Animals in silviculture
Silviculture as distinct from agro-forestry means simply that the main product is animal production. These systems are of frequent occurrence. Recently I observed a system being exploited in Cuba where rows of leguminous tress, e.g. Leucaena, were used, interspaced with grass. Here again the trees provided N for the grasses. However, another aspect of this has been noted, namely some tree leaves reduce the faecal counts of nematodes and coccidia of the grazing animals. This can be illustrated by some work from Vietnam in which a comparison was made between Leucaena, jackfruit and cassava leaves with two types of grasses (Table 3, Lin et al., 2003).
The goats were dewormed using anthilmintic and then given the different feeds. The effects of coccidian counts were similar to that of nematode eggs. It can clearly be seen that the increase in egg count after deworming was much less in the goats receiving the leaves of the plants than those receiving grasses. The effect of the browse plants is probably due to the tannin contents though cassava leaves also contain some cyanide compound. It should of course be noted that tannins are not a uniform compound but can, in high amounts, have antinutritive properties. In the work of Lin et al., (2003) live weight gain was also higher in animals receiving tree foliage. The effects of condensed tannins on gastrointestinal parasites are further discussed in Mui et al., (2005).
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Table 3. Number of nematode eggs in faeces of goats given different forages (eggs/g faeces) (Lin et al., 2003)
Date Cassava Jack fruit Leucaena Guinea grass B. Rusi grass
Before 1757 527 1680 687 438
After deworming
30 days 23 22 31 86 95
60 days 265 162 107 533 617
90 days 583 433 350 1042 1152
120 days 870 672 502 1872 2425
150 days 1170 1012 722 3870 4312
Live weight
gain p/d 43 39 42 34 25
Multiculture with Rice, Ducks and Fish
Another aspect of multiculture is illustrated in Table 4. Here, instead of using herbicides in the paddy fields, ducks were introduced. The result was duck production as well as rice production. In fact there was no reduction in rice yield. After that fish, Carp and Tillapia were also introduced together with ducks for growing, or egg-laying. The rice yield may have been slightly increased and the total benefit to the farmers increased by more than 20 times per unit area of land. No doubt, there was more labour involved, but an introduction of herbicide resistant rice would have eliminated the need for both fish and ducks and would have further increased cost. There are many options like this that can be explored with both environmental and socio-economic benefits.
Table 4. Integrated system of rice, rice plus duck, rice plus fish and duck on net financial benefit to farmers (Mill.Vietnam Dong/ha) (1 USD approximately 15000 Dong)
Systems Rice Duck Rice Duck Fish
Rice
Layer Duck Fish Rice Inputs:
- For rice 6.62 3.92 3.92 3.92
- For duck - 8.70 8.70 52.92
- For fish - - 13.90 13.90
Total 6.62 12.62 26.52 70.74
Outputs:
- From rice 8.56 8.03 9.85 10.44
- From duck - 14.50 14.50 68.02
- From fish - - 46.39 47.92
Total 8.56 22.53 70.74 126.38
Net benefit +1.94 +9.91 +44.22 +55.64
Technology transfer from developed to developing countries
I would like now to make a few critical comments about technology transfer that I encounter frequently. I hope it has been made clear that the transfer of labour saving, high fossil fuel consuming, and technologies provide no solution. In fact, maybe some transfer should go the other way as far as environmental sustainability is concerned. Mono-culture, including herbicide resistant GM cropping, is generally not a solution. Introduction of such inappropriate technologies is often fuelled by persuasion, disguised as attractive study tours,
41
or consultancy fees, for government personnel and purchase of research capacity in universities or research institutions.
So-called upgraded or superior animals, selected for high yield in a temperate country are exported to areas where the environment is not controlled of sub-tropical or tropical countries. In these situations survival possibilities are generally less than 50:50. This is particularly a problem in humid tropics. Survival is better in dry tropical areas. Animals in most developing countries generally cannot be kept in air conditioned houses. Large allowances of grain are unavailable, so the animals are unable to achieve their genetic potential, owing either to climate or to feed quality restrictions. So-called high quality semen is exported from countries such as Canada, but a superior bull in a cool climate may be totally inferior in a hot climate, where rate of heat dissipation is an important characteristic.
However, a limited amount of crossbreeding between exotic and native breeds may be successful in some areas. The same comment may be made about export of so called upgraded chickens and pigs. Many such inappropriate technologies are exported in the name of aid. The beneficiaries are generally the exporters.
Rural poverty alleviation
What is the best form in which developing countries can be assisted and rural poverty alleviated? In Africa and Asia by far the largest and the poorest populations are in the rural areas. First of all there is no one solution. Each area has its own constraints and possibilities imposed by climate, soil and socio-economic circumstances. There is, however, one aspect which is common to all such regions, and this must always be remembered. Poor farmers cannot take risks. If the choice is between low risk, low gain or high risk, high gain, then the poor will always choose the former. This is important in that if we wish poor farmers to increase their productivity of crops or animals, this increase must be relatively free from risk, otherwise they cannot be persuaded to respond. There is also a problem of fluctuating prices.
Such fluctuation can be caused by the dumping of subsidised products from Western Countries and by the WTO, which freely allows trading of highly subsidised products from the west. This trade restricts the ability of developing countries to underpin local prices which give security to the producers.
Another aspect concerning animals is that the poor farmer prefers small to large animals. If the choice is between 10 goats and one cow, he will invariably choose the 10 goats. If one goat is lost there are 9 left. If one cow is lost, all is lost. This is known as risk spreading and is discussed in some detail by Ørskov and Viglizzo (1995). Also, risk can be reduced by better education and small farmers can be encouraged to form co-operatives for marketing and production purposes. Then they become a stronger unit to negotiate with middlemen. Marketing is complex – sometimes governments find it easier to stimulate large peri-urban animal production units creating endless pollution problems.
The increasing urban demand created by increasing urbanisation must, as far as possible, be satisfied by rural production with the alleviation of rural poverty. The demand should not be accommodated by supporting large scale peri-urban animal or crop units, or by the importation of subsidised products from Western countries, except during years of drought and famine.
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References
Blaxter, K.L., 1989. Energy metabolism in animals and man, Cambridge University Press, Cambridge, UK.
Clerkin, S., 2002. Incorporating biodiversity in Policy, Biology and Environment.
Royal Irish Academy, 102, 177-182
Devendra, C., 2004. Integrated tree crops – ruminant systems. The potential importance of the oil palm. Outlk. On Agric. 33: 157-166.
Lin, N.K., Preston T.R., Binh, V.D., and Ly, N.D., 2003. Effect of tree foliages compared with grasses on growth and intestinal nematode infestation in confined goats. Livestock Research for Rural Development 15 (6).
Minh, T.N., L.V., Ly and E.R. Ørskov, 2003. Using local ducks to control insects in paddy field and in duck, fish, rice systems and eliminate use of insecticides. SAREC International meeting.
Hue, Vietnam 22-26 Marc 2003.
Mui, T.N, Binh, D.V., and Ørskov E.R., 2005. Effect of foliages containing condensed tannins on gastrointestinal parasites. Animal Fd. Sci. Tech. [In press]
Ørskov E.R., 2002. Trails and Trials in Livestock Research. IFRU Publication, Macaulay Institute, Craigiebuckler, Aberdeen, Scotland.
Ørskov E.R. and Viglizzo, E.F., 1994. The role of animals in spreading farmers risks. A new paradigm for animal science. Outlook on Agriculture 23, 81-89.
Pathirana, K.K., Mangalika, U.L.P., Liyanage, M. De S., Ørskov, E.R., 1996. Effect of grazing and supplementation in a coconut plantation on cattle production, coconut yield and soil fertility.
Outlook on Agriculture 25, 3, 187-192.
Sibbald, A. R., 1999. Agro forestry principles – sustainable productivity? Scottish Forestry, 53 (1):
18-23.
Tuah A.K., Lufadeju E., Ørskov E.R. and Blackett G.A., 1986. Rumen degradation of straw.
Untreated and ammonia treated barley, oat and wheat straw varieties. Anim. Prod. 43, 261-269.
43 Plenary 5