Livestock Research for Rural Development 14 (5) 2002

Citation of this paper

Future direction of animal protein production in a fossil fuel hungry world

R A Leng

Emeritus Professor, University of New England, Australia
University of Tropical Agriculture
Chamcar Daung, Phnom Penh, Cambodia



Supply  of meat and milk in developing countries must be increased considerably in the next 20 to 50 years if the predicted demand is to be satisfied.  Poultry and pig industries are targeted as being the most likely production systems, with the potential to develop at a rate commensurate with the demand for meat. However, there will be major changes in the energy sector that are bound to affect such intensive systems. The price of oil is certain to increase as sources of fossil fuel become depleted; and grain prices will also rise as this commodity is increasingly being used as a feedstock for industrial alcohol production, especially in the United States.  These trends will challenge the inevitability of future increases in meat coming from pigs and poultry produced in industrialised conditions on grain. In such a situation, ruminant production from forage-based systems could be a more sustainable alternative.


A new analysis of the results of supplementation trials where cattle have been fed on poor quality forages and agro industrial by-products, shows that production can be increased several-fold when treatment to increase feed digestibility and supplementation are combined. Supplementation involves providing minerals and urea to satisfy requirements for efficient digestion by microbes in the rumen and augmenting the protein supply to the animal through feeding an escape protein meal.  Protein meals appear to have differing roles according to their level of inclusion in a low digestibility roughage based diet. When fed at low levels, the response in growth of cattle is apparently four-fold greater than to similar increments of protein supplements above a critical level.


As oil prices rise and the cost of grain and therefore industrialised meat production increases, the challenge for the future will be to capture the potential for efficient utilisation of ruminants for milk, meat and fibre production. The huge numbers of ruminant animals in Asia and their general subsistence level of production at the present time suggests that the potential is already present in these countries to lift production from these animals by as much as five-fold.


Key words: Fossil fuel, grain, alcohol, live stock, meat, milk, monogastric, ruminants, crop residues, protein supplements, bypass protein, rumen nutrients



It is predicted that in the foreseeable future there will be a greatly increased and continuing demand for protein foods of animal origin for human consumption in developing countries particularly in Asia (Delgado et al 1999). In recent times human nutritionists have highlighted the important role of animal protein in human health particularly during pregnancy and early life on the subsequent development of children. Maternal protein intake throughout pregnancy is related to birth size, and therefore future viability of children. Where protein under-nutrition occurs, dietary protein from any  sources is important in human development but increased intake of  meat protein appears superior for stature development (Waterlow 1998). Sources of dairy protein, in particular, has had a greater effect on prenatal development and size of  the new-born child (Moore 2002) .

In overall terms the major issues that will determine future meat and milk supply are:

         Which species will be best supported by the available resources

         Which production system is appropriate to the country

Major increases in milk production are only achievable from development of dairying with cattle and buffalo. But the choice of species for future meat production will have important effects on other aspects of human food production. Industrial production of pig and poultry meat is largely based on use of cereal grain.  This in turn depends greatly on energy costs, particularly the price of liquid fuel.


The factors that will impose constraints on the future development of meat industries from monogastric animals is the inevitable decline in availability of fossil fuels and the likelihood of substantial price rises for fuel. Modern agriculture is highly dependent on inexpensive oil and the associated increases in crop yields are a result of high inputs of oil associated with traction power, fertilisers, herbicides, transport and others (see Table 1). Scarce and expensive oil will impose major constraints on future food production in general. Competition for feedstock from the developing alcohol industry in the United States, in particular, will also result in pressure on grain availability and price. Modern, mechanised agriculture has increased grain yields as compared to traditional agriculture dependent on human and animal traction. The improved yields have been largely a result of direct and indirect inputs of oil in machinery, and production and transport of fertilisers and other inputs.  The efficiency of energy use is, however,  markedly reduced in modern agriculture as compared with traditional systems (Pimentel 2001)

Table 1. Non-mechanised agriculture versus mechanised agriculture


Non-mechanised agriculture

[ Developing countries, e.g. Mexico]

Mechanised agriculture

[ Industrialised countries, e.g. United States]


Mechanised v/s
Non mechanised agriculture

Energy inputs [MJ /ha]




Grain yield [MJ /ha]




Grain yield [kg/ha]




Energy in grain/energy inputs




The assumption that the world can afford to produce the large quantities of grain required for the development of major industrial live stock production (Figure 1), foreseen by Delgado et al (1999, 2002) seems improbable.


Figure 1.  The trends in requirements for feed grain by industrialised pig and poultry
production to meet the anticipated demand for meat by 2020 (Delgado et al 2002)


Meat and milk production from ruminants fed diets based mainly on cellulose-rich biomass is much less dependent on the price of oil and in the future the cost of ruminant meat should become much more competitive with meat from monogastric animals.

Resource depletion and future agriculture

Although the industrialized nations and many countries with emerging economies have become largely self sufficient in food, it appears that the world is poised on the edge of major disruption in feed and food resource availability if oil prices rise substantially. The development of high yielding cereal varieties, together with mechanization of agriculture and inexpensive inputs of fertilizer and water made possible by inexpensive oil, led to massive increases in crop production over the last 20 years. The availability of inexpensive cereal grain allowed the industrial production of pig and poultry meat at prices affordable by the middle-class but often out of the reach of the poor.  However, the era of inexpensive fuel appears to be ending as world supplies of fossil fuel become depleted (Figure 2), the available land for crop production declines and populations increase. It is also likely that the high levels of subsidies, which support agriculture in industrial countries, will be phase out in time. This will also result in higher grain prices.

Figure 2. The past and predicted future pattern of world oil production, including non-conventional sources (as Giga barrels
 of oil equivalent) (Source: ASPO 2002)

The world oil situation

The world oil situation can be summarized as follows (see website

         World oil production has peaked (Figure 2)

         There are few  “ yet to be found” oil fields and future discoveries will be insignificant in relation to use (Figure 3).

         Most of the major oil fields are well into decline and the largest fields that have not yet peaked in production are those in the Middle East Gulf countries. These countries have 75% of the total world reserves (Figure 3).

         Extraction of oil from the second half of an oil field is much more expensive  and  this alone will increase oil prices substantially.

         Because of the high costs of oil extraction from reserves of alternative fossil fuels, these are not likely to come on line until the price of fuel is increased substantially.  Even then they can only supply a relatively small proportion of the world’s total fuel requirements (Figure 2).

         The United States which uses 30% of world oil production and is now 60% dependent on imported oil, is already diverting maize into fuel alcohol production. It is predicted that by 2005, maize for alcohol will account for 21% of US production capacity, which is equal to the present surplus (presently exported) production (Figure 4). Many other countries are now assessing their options for producing alcohol  from sugar and grain .


Figure 3. Oil used, current reserves and "oil yet to find", in countries that are major oil producers (Source: http://www.oilcrisis/)



Figure 4. The predicted maize grain use for industrial alcohol production in the United States (Source: Pearse Lyons and Bannerman 2001)


The price of oil must rise, considering the decline in oil production, the increasing monopoly of the oil markets, and the increasing demand for oil as countries develop and populations grow. Intensive, mechanized grain production, as practiced by the exporting countries, depends heavily on inputs of fossil fuel (Table1). In the future, the competition for grain for food, feed and feedstock will surely mean that this commodity will become more expensive.


The markets for meat in most developing countries are presently expanding at 3% per annum. If grain prices rise substantially, with a flow on to meat prices, this will either reduce consumption or change the choice of meat by the public. Expensive grain may create major opportunities to develop ruminant production systems that do not require grain and do not compete for food with humans nor feedstock for alcohol production.


The future role of ruminants in meat production

Undoubtedly industrial systems of poultry/pig production deliver the high quality meat that the middle classes are demanding. The trends in demand for meat are a reflection of an increasing middle class in Asian countries who probably already have well balanced diets for protein.  There is, however, a clear moral issue for the production of animal protein that is affordable on a regular basis by the poor. With this in mind the development of meat and milk industries should be so structured as to allow the poor to share in the outcomes, whether it is from increased income and nutrition or both.

Development of efficient, but necessarily dispersed, ruminant meat and milk production industries will benefit the rural poor, both as producers and consumers. In contrast, industrialised systems of meat production require considerable investments and will be monopolised largely by middle class producers. Such systems have other disadvantages, as they contribute to urbanisation and incur major problems with waste disposal and water pollution.

Widely dispersed ruminant production systems based on roughage and agro-industrial by-products appear to offer greater hope for meeting the demand for large quantities of medium to high quality protein for human consumption at affordable prices. An example of such a system is the milk production scheme developed by the National Dairy Development Board in India.

Using crop residues for ruminant productivity

The major available feed resources for ruminants in most developing countries are crop residues, agro-industrial by-products, cut and carry weeds/grasses, foliage of trees and shrubs and water plants.  Straws from rice and wheat, and stovers from maize, sorghum and millet provide most of the available biomass but are imbalanced with respect to protein and minerals. The content of digestible energy in these forages is low, even when treated with alkali to increase digestibility, leading them to classified as poor quality forages, which is a highly misleading label . By traditional energy standards they should only be able to support maintenance or slightly above (Chenost and Kayouli 1997).  The standards, however, underestimate greatly the production levels that can be achieved with these forages when the recipient animals are strategically supplemented with both rumen nutrients (mainly ammonia, sulphur and phosphorus) and bypass (escape) protein (Dolberg and Finlayson 1995; Finlayson et al 1994; Leng 1990; Preston and Leng 1986; Seng Mom et al 2001).

Supplementation strategies for young cattle on low quality forage

Large numbers of experiments have demonstrated the benefits of supplementing rumen nutrients (eg: multinutrient block licks; Leng 1984, Leng and Kunju 1990), and bypass protein meals (Preston and Leng 1996) to ruminants given  poor quality forage.  The results from a number of experiments designed to elicit response relationships, carried out in many countries, are summarized in Figure 5 (Poppi and McLennan 1995; Leng 2002).

Figure 5. The response of young cattle fed poor quality roughage to supplementation with a source of bypass protein (NB: the "Y" axis is the increase in live weight gain over and above the unsupplemented control; a logarithmic relationship appears to best describe these data)

As discussed previously (Leng 2002) a source of bypass protein may have differing roles when fed to ruminants at low as compared to higher levels of inclusion in a forage diet.  It may therefore be more appropriate to plot two linear relationships (Figure 6):

(1) for protein supplement rates between: 0 and 1 g/kg live weight
(2) for protein supplement rates between 1 and 6 g /kg live weight

Figure 6.  The response of young cattle fed poor quality roughage to supplementation with a source of bypass protein, considering two independent relationships for protein supplementation rates  (1) between 0 and 1 g/kg live weight, and (2) between 1 and 6 g/kg live weight


The hypothesis is that the initial increase in amino acids from bypass protein relative to energy corrects an imbalance in nutrient availability that improves the efficiency of live weight deposition.  Thereafter, with increased levels of bypass protein the increased live weight gain is merely a reflection of greater availability of a well balanced array of amino acids and energy nutrients.  Overall, the aggregation of results from many countries illustrates that so-called "low quality" forage can be used very efficiently to produce ruminant products. 


The rate of increase in live weight gain on a forage-based diet, that can be achieved with bypass protein supplementation, is predicated on an efficient rumen fermentation, which requires adequate levels of ammonia, sulphur and phosphorus. The level of production that can be achieved depends mainly on the digestibility of the forage and this can be raised by alkali treatment. The research in China showed clearly that the combination of straw treatment with bypass protein supplementation was capable of supporting growth rates in cattle comparable with those on grain-based diets , with commensurate improvements in the efficiency of straw utilization (Table 2). The point that needs stressing is that by treating forage sources to increase digestibility and providing the necessary supplements it is possible to increase meat from ruminants by 10 to 13 fold from the same quantity of poor quality forage.


Table 2. The potential of balanced supplementation to increase meat production from young cattle fed low quality crop residues treated to increase digestibility. The calculations are based on the data from research in Hebei, China (Zhang Weixian et al 1994)

Cottonseed cake supplement, kg/day







Live weight gain , g/day







Straw  to produce 100 kg live weight, tonnes







Cottonseed cake to produce 100 kg live weight, tonnes







Straw conversion, kg straw DM/kg live weight gain







Number of animals that can achieve an extra 100kg of live weight on 6 tonnes of straw







g LW gain per g of cottonseed cake








Response to bypass (escape) protein in dairy cows
The response in milk production to supplementation with rumen nutrients and bypass protein by dairy cows given poor quality forage is more difficult to rationalise. This is made difficult because of the problems of the interaction of genetic potential and nutrient partitioning between milk and live weight. In milking cows given forages, supplementation with bypass protein has major effects on live weight change, often reducing live weight loss in lactation (Figure 7).  In lactating cows, there is a high correlation between body condition (live weight) and the ability to conceive, thus supplementation with sources of bypass protein often increases milk yield substantially, reduces inter-calving interval and improves overall reproductive efficiency.

Figure 7. Interaction between supplementation and nutrient partitioning in lactating cattle fed a basal diet
of sugar cane (Source: Kass et al 1992)


The concept that grain-fed pig and poultry meat will be able to supply the future demand for protein foods in developing countries is compromised by dependence on inexpensive oil and cereal grains. Declining availability of both these resources is inevitable with consequent price increases. Ruminant production systems are better placed to meet the predicted increases in demand for meat and milk, as the animal resources and the feed base of cellulose-rich biomass are abundantly available and inefficiently utilised at present.


The research that has been highlighted in this paper indicates that appropriate supplementation of poor quality roughages, combined with alkali treatment, can raise ruminant meat and milk production to the same levels as are obtained on high quality pastures in temperate latitudes. 



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Received 10 October 2002


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