Rprogress is being made in developing alkali treatment technology and there is now no doubt about its technical feasibility. Attention naturally turns, therefore, to the economics of treatment. With the information and experience now available it is possible to assess the economics with some precision. To make this assessment, three differing situations must be distinguished. These are:
Where straw is already used as a livestock feed on the farm.
Where straw is available on the farm, but is not fed to livestock, though there are livestock on the farm.
Where straw is produced on farms where there is no livestock.
An important limitation of this assessment will be that the feeding trial data presently available are from trials in which the highest possible treatment efficiency was not achieved for reasons discussed in the previous chapter. Thus estimates of profitability will be conservative for the most part.
Situation 1--straw is already used as a feed on the farm
In most countries of Asia and in many countries of Africa, straw is fed to livestock; indeed it is often the staple feed. Even in some parts of Europe straw is traditionally fed to livestock. Such areas are Scotland and Scandinaiva where fodder beet forms an important item of the livestock diet. Wherever it is fed, straw harvesting, transport from fields and storing away from bad weather are all routine operations and are integral parts of the larger farm operation. The economics of straw treatment are therefore straight forward; the cost of treating straw must be compared with the returns accruing from increased animal productivity. The treatment of straw is not likely to require any important changes in the farmer's existing pattern of farm operations.
In India, the alkali treatment of straw by the daily treatment dry method has been found to result in substantial gain in terms of feed cost per kg gain in liveweight and earlier maturity (tables 16 and 17). These diets are typical of those fed on larger farms in the irrigated parts of the Northern states. In more difficult situations little or no supplementary forage or concentrates are fed. Kehar (1954) experimented on animals maintained in villages by their owners. He used the Beckmann method, but even then the economic benefit was substantial (table 26). The heifers were being maintained on only very limited amounts of supplementary feeds and these too were given irregularly. They suffered all the usual vissitudes of a poor village environment. The simple treatment of the straw doubled rate of weight gain, increasing it by 0.08 kg per day. Much more could probably have been achieved if supplements of urea had been fed along with the treated straw and if the straw had been fed ad libitum. The results of a recently completed experiment on buffalo heifers, also in India (Khurana and Naik, private communication--1978), are also significant in this context. They were experiment station animals and the experiment was designed to determine the separate as well as combined effects of urea and alkali treatment. The description of the treatments as well as the results are given in table 27. All the animals lost weight for the first month on the trial, having previously been well-reared on green forage and concentrates. Thereafter those on the urea and the urea-treated straw began gaining, while those on the control and the treated straw continued to lose. The gains are calculated for a period of 4.5 months disregarding this first month's performance. The improvement in weight gain by a combination of urea and straw treatment is considerable--0.28 kg/day. If urea and straw treatment were superimposed on poor village feeding practices (weight gain of 0.1 kg/day) and a similar increase obtained (ie., 0.28 kg additional gain/day) there can be little doubt that the economics would be favourable. Further experiments of this type need to be done, but for realistic economic assessment, such experiments should be done on village animals, as Kehar did, rather than on experiment station animals. It is therefore suggested that a field testing programme be taken up in countries where straw is the staple feed. A proposal for such a programme is given in part VI of this report.
|Straw consumption, kg/day (dry straw basis)||3.0||3.0|
|Feed cost, Rs./head/day||0.36||0.56|
|Liveweight gain, kg/day||0.10||0.18|
|Days to gain 100 kg||1104||563|
|Feed cost per 1 kg gain, Rs.||3.57||3.12|
*see paragraph 88 for description of experiment.
Source: Kehar, 1954
It may be asked why the treatment of straw was not taken up by farmers in India long ago if the economics were favourable. The answer is that new practices have to be demonstrated on the farm to convince farmers of their usefulness. This was not done because there were no organisations to do it. Now there are several agencies that are engaged in livestock development work that could effectively demonstrate straw treatment on the farm. The demonstration of straw treatment is also one aspect of the proposal given in part VI of this report entitled “A proposal for a coordinated field-testing and demonstration programme”.
|Diet*||Organic matter digestibility, %||Dry-matter intake g/kg W0.75||Digestible organic matter intake g/kg W0.75||Daily gain, kg**|
|Treated wheat straw||55||51||25||-0.08|
|Wheat straw + urea||48||65||29||-0.08|
|Treated wheat straw + urea||57||81||40||+0.13|
* The treatment of wheat straw was done by the daily treatment dry method using 5 kg NaOH/100 kg straw. Urea made into a solution was sprayed on the straw at the rate of 2 kg/100 kg dry straw. Each animal was also given a green maize or sorghum forage supplement containing 0.5 kg DM/100 kg body weight per day
** Average weight gain over a period of 41/2 months. Initial weight of animals was 200 kg.
There are several ways to organise straw treatment. These include treatment on individual farms, co-operative treatment plants and custom service on the farm by co-operative societies or private operators. Methods of treatment exist or can be devised for all of these situations. The choice of organisation may largely be made on considerations of cost and convenience. In Asia where farms are small and labour abundant, daily treatment on the farm itself may well be the most economical. But with a simple alkali treater, even bulk treatment and stacking is feasible, since farmers anyway stack their straw at harvest time. A small treater which produces treated straw similar to that produced by the Danish farm machines has been developed in India (Agrawal et al., 1977). It has an output of 0.3 tonnes/hour and operates on a 5 hp motor. Manufacturing cost without motor is Rs. 3000. Simple machines like wheat threshers and diesel engine-powered pumps are already widely manufactured and used in Asia, and a straw treater such as this could also become a common farm machine, using a common farm engine or electric motor. On the other hand, where strong co-operatives exist, community treatment plants could be set up. The disadvantage to these is the extra cost of transporting straw to and from the plant. Even in Norway, it is questionable whether or not the co-operative plants can continue to operate in the face of increasing costs of transporting straw. In Europe, custom operators using a tractor-powered treating machine of the Danish design would seem to be an economical way to treat straw. The consultant saw one such operation in Britain; a custom operator visited the farm of each contracting farmer once a month or so and prepared a stack of treated straw.
Although the economics of straw treatment appear very favourable in India, it is well to recognise that there are definite constraints to how much could in fact be treated. The treatment of straw must be accompanied by the feeding of larger amounts of a protein supplement. Supplies of oilcakes are severely limited. Exports of oilcakes contribute to this and therefore any consideration of popularising straw treatment should at the same time include a consideration of oilcake export policy. The use of urea as a protein supplement with treated straw is an alternative to the feeding of oilcakes, but supplies of urea are also limited. An argument in favour of using urea for livestock feeding, is that the nitrogen fed to the cow in this manner finds its way to the soil-or at least can do so if the urine and dung are properly handled. A hopeful development in this context is the steadily gaining popularity of the dung gas plant. Another important consideration is the energy cost of NaOH manufacture. It is high, some 51 MJ/kg. Limited supplies of electricity have to be allocated among NaOH production, ammonia production (77 MJ/kg N) and many other vital uses. Energy supply for NaOH production may prove to be a constraint to straw treatment at some point in many countries.
Situation 2--straw is available on the farm, but is not fed to livestock, though there are livestock on the farm
In this situation treated straw becomes a potential substitute for other ingredients in the existing livestock diet. A number of substitution experiments have been done. The results indicate that high-quality treated straw is equal to maize silage and good grass silage in feeding value in high-roughage diets if the difference in protein content is made good by adding extra oilmeal to the treated straw-containing diet. Available evidence indicates that this equivalence is maintained when treated straw and silage are fed in the dairy-cow diet (paragraphs 40, 56 and 81). In beef-fattening diets composed of barley and oilcake, the feeding value of treated straw as a replacement for some of the barley has been found to be slightly less than half that of barley, taking into account the lower protein content of the straw (Greenhalgh and Pirie, 1977).
The question that has now to be examined is whether or not treated straw is an economical feed. From the data in table 22 the authors calculated that the treated maize-husk diet would give cheaper liveweight gains whenever the price of maize grain (from which the price of maize silage is calculated) is more than U.S. $ 80/ tonne, assuming a price of $ 207 for the soyabean meal supplement they used. The cost of the treated husks was taken at the cost of production (collection on the farm, treatment and ensiling) which was calculated to be $ 27/tonne. At present, maize grain prices in North America are too low to make this substitution profitable. Miles (1977) has calculated that treated straw in the U.S.A. costs more than lucerne hay after making up its protein content with soyabean meal, assuming it has 60% as much net energy as barley grain.
The economics of treated straw have been studied in Denmark (Kristensen, private communication--1977). The cost of treating straw with the NaOH by the bulk treatment and stacking method and by the NH3 stack method were equal if the farm NaOH treater (cost about Kr. 66,000) is used for 6 months in a year. The substitution of straw treated by either of these methods for silage becomes advantageous when the cost of silage exceeds Kr. 600 (S£66) per tonne of silage dry-matter and the cost of oilcake (35–40% protein) exceeds Kr. 1600 per tonne (S£ 176), considering the treated straw and the silage to have equivalent net energy values and taking the average market price of straw plus treatment costs and for the silage the cost of making silage from grass and the opportunity cost for the land used to grow the grass. This situation approximately obtained in 1977.
Greenhalgh and Pirie (1977) have calculated a money value for the NaOH-treated straw in their experiments (table 15--beef steers) of S£ 30–40/tonne of material containing 85% dry-matter. This is relative to barley and soyabean meal at prices of £ 90 and £ 180/ tonne, respectively. The cost of picking up straw from the field, baling it and transporting it to the farm store is some £ 5/tonne (Radley, 1976) and treatment cost in their experiments was £ 10/tonne. Thus actual cost on the farm is about £ 15/tonne and where there is no market for a straw, it is a very economical roughage. This cost is also only about one-third the market price of hay of equivalent net-energy value. Usually, however, the straw has a market price, and this ranged at the period when these experiments were done from £ 10–25/tonne. At prices of up to about £ 20/tonne, it would probably be advantageous for the farmer to substitute treated straw for hay and silage but above that price, usually not. Even if there is a poor market for straw, but the farmer uses it at present as bedding, it will cost him something to change from using straw as a bedding material to using it as a feed. If he is not harvesting all his straw, he may have to invest in more storage in order to do so.
An interesting additional feature of the results of the experiments of Pirie and Greenhalgh (1977) is the figure they calculated for the value added to straw by treatment; it was £ 18/tonne after deducting £ 10/tonne treatment costs. It is useful to have an untreated straw comparison in such feeding trials to indicate how much benefit is in fact derived from the treatment.
There is considerable interst in using straw in barley-based beef fattening diets in Europe. Palmer (1976) summarised the results of a large number of feeding trials with untreated straw. His calculations show that the inclusion of ground straw in such diets at any level between 0 and 50% increased feed cost per kg liveweight gain. This effect would have been more pronounced if feed costs were calculated per kg of empty body gain (Kristensen, 1975). The inclusion of straw also further decreases returns from fattening cattle by prolonging the period required to achieve a given weight gain. The feed costs per kg empty body gain in steers in the experiment of Pirie and Greenhalgh (1977) (table 15) with treated straw were also increased even if a price of only £ 15/tonne is taken for the straw (cost of collection on the farm plus treatment cost). Rate of liveweight gain was also depressed, lengthening the finishing period. It thus appears that the barley-based, beef-finishing diet is not a place where treated straw can be used profitably at present. Claims are made that small amounts (upto 20%) of treated ground straw can be included in such diets with profit. There does not appear to be sufficient experimental data available at present to substantiate this claim.
In conclusion, it appears that on many mixed farms in Europe where farm-produced straw is not presently used as a feed, there is an opportunity to treat it and use it as a roughage in whatever ways hay and silage are presently used. There are two ways in which the farmer can take advantage of this opportunity; he can increase his herd strength or reduce his acreage of grass. If he adopts the former, he will have to buy additional concentrates. This will appeal particularly to the farmer with limited land. It may not, however, be possible for large numbers of farmers to do this because cereal and oil meal prices would increase and become a constraint. Supplies of these commodities on the world market are unlikely to increase in the future; they are more likely to decrease, especially the supply of oilmeals since exporting countries may begin to use more at home and export less. World proces for livestock products may also not favour any large increases in total output. If the farmer adopts the latter approach, the question is what crop he will grow instead of grass. His preference would usually be for cereals. How many farmers could do this and to what extent depends upon how much of present grassland is suitable for cereal production; much of it is only marginal for this purpose. Also, this second alternative approach would require more oilmeals. The opportunity for using more straw in Europe that appears to exist at todays prices might, therefore, be small compared to the quantities of straw available for use.
The special situations obtaining in Malaysia and in Egypt where straw is not completely utilised, though livestock are maintained on the farm, are discussed in the individual country reports in part V.
Situation 3--straw is produced on farms where there is no livestock
Over the past 30 years or so farming in Europe has become increasingly specialised and today there are many farms which carry no livestock. These are the specialised cereal crop farms in areas of good arable land. Examples of such areas are south-east England, the eastern islands of Denmark, south-east Norway and the area around Paris. Most of the straw that is burnt is on these farms because there is no use for it. On the other hand there are specialised livestock farms in areas with less favourable soil and terrain where straw might be fed. The economic problem is the cost transporting straw from one part of a country to another. Cost studies in Great Britain reveal that straw transport over short hauls of 8 km or so cost £ 0.52/tonne km (lorries with 12 m beds) and for long hauls the cost was £ 0.04/tonne km (6.5 m lorry beds) (Radley, 1976). Thus a short local haul adds £ 2/tonne and long haul of say 200 km adds £ 8/tonne to the cost of straw. A similar situation has been reported from France (Gaudier, 1977); straw with a local market value of F 200 can end up costing F 400 if transported 300 Km.
One approach to the utilisation of straw in cereal growing areas is to set up straw treatment factories in such areas. Straw is collected from farms within a radius of 10–20 Km of the factory by the factory management or through haulage contractors. It is then alkali-treated and pelleted. The density increases from less than 100 Kg/M3 for baled straw to 400–500 kg/M3 for pelletes. The pellets can then be transported, handled and stored more cheaply than the original baled straw. A number of factories in Europe are operating on these lines. The problem of transporting bulky baled straw from the farm to the factory still remains and research is under way to devise high-compression balers and mechanised handling systems (see, for example, Chaplin, 1976).
The economics of the straw-treatment factory are not yet clear. Most of the treated straw is being marketed through conventional compound-feed mixtures. Typically 10–20% of ground, treated straw is included. What the nutritive value of treated straw has in this situation, or whether it is any better than untreated straw, are matters which have yet to be elucidated. The compound feed industry is able to absorb the comparatively small amounts of treated straw so far produced at prices that encourage its production. Very little treated straw is sold to farmers directly. They could use it in the same ways as farm-treated straw--as the equivalent of hay and silage. Doing this would presumably be most attractive to farmers with small holdings and hill farmers who could also buy additional cereals and protein supplements and increase herd/flock size. The amounts of treated straw that could be used in this way are unknown at the moment. Much depends upon the price at which treated straw could be sold and still make it reasonably profitable for the company producing it. The general constraints on the increased use of straw in Europe (paragraph 98) also have a bearing on this question.
Another approach might be to re-introduce livestock on cereal farms. The problems are, however, considerable. Those farmers who have thought of this have considered beef fattening operations. A few cereal farmers have already set up such operations. But the use of straw, even when treated, in intensive beef fattening is uneconomical at present (paragraph 97). More extensive livestock systems are probably not feasible, which is why they died out on these very farms only a few decades ago.
The cereal farmer who does gain a market for his straw has to make a number of changes in his farm business. First he has to forego the economic benefits of straw burning. These include rapid field clearing and effective field cleaning. If he does not burn he may have to spend as much as £ 25/ha for extra tillage and herbicides. There is an increased requirement for labour and machinery at peak work periods. These and other changes have been discussed by Radley (1976).
Straw has other uses than as a livestock feed. Much is used for bedding animals, though newer systems of housing livestock use little or no straw. It is used for raising mushrooms, as a mulch, for the manufacture of paper, fibre board, as a raw material in chemical industries and as a fuel. In Europe, the combined demand for all these uses is only a small fraction of the straw produced (about 10% in France, for example). With present relatively abundant supplies of wood pulp and oil on the world market, only a very slow increase in the demand for straw for these non-feed uses is likely. In this connexion, an interesting development is the whole crop harvesting and processing system. The whole cereal crop is harvested and transported to a nearby factory where it is dried and fractionated into grain and various straw fractions. A light fraction, consisting mainly of leaves and amounting to some 40% of the total weight of straw has been found to have a digestibility of between 60 and 70%. This might be used for livestock feeding even without treatment. Heavier stem pieces constitute a second fraction which would be suitable for paper and fibre board manufacture. A still heavier fraction is the straw nodes which might be used for chemical manufacture or fuel. All manufacturing units would form a constellation around the primary crop fractionation plant. The economic advantage is that the whole crop can be harvested and brought to this plant for the same cost as is now common for combine-harvesting of grain and transporting it to market. A pilot operation has been set up in Sweden. The foregoing is a summary of the description given by Claesson (1977) at the 1977 Oxford straw Conference.
In India large amounts of straw are hauled into the cities from the countryside, not because there is no livestock on the farms from which the straw comes, but because there is a great demand for it to feed city cows and buffaloes. It appears therefore, that the factory processing of straw in rural areas might be economically feasible; it would reduce transport and storage costs and at the same time improve the feeding value of the straw. A pilot plant has been set up to study this possibility, and one or two more such plants might be set up in different regions of the country for the same purpose. As in Europe, the commercial success may well depend entirely on the savings in transport and storage costs resulting from pelleting, since equally effective alkali treatment can be done by any of the farm methods more cheaply where the cattle are fed.