By Rick Kleyn, SPESFEED (Pty) Ltd, South Africa.

Biofuels are truly the topic de jure in agricultural circles. It is likely to be the single most important event in agriculture for decades. Those of us involved in Agribusiness need to have a grasp of what this movement entails and what the short and long-term impacts of its production are likely to be. It is true that some prices will firm, maize in particular, but the possibility that other prices may drop exists. The by-products of the biofuels industry may well represent an opportunity to nutritionists, but they are certainly not going to be “magic” new ingredients. Unless these ingredients are within acceptable tolerances in terms of their nutrient content and correctly priced, nutritionists will simply not use them.


In essence political issues are driving the entire biofuels movement. We are currently in a period of hyper-responsiveness to energy issues. International affairs, domestic supplies, global energy competition, and a wide array of opinions and options about what to do about our future energy needs confront us, Swenson (2006).

Governments have an interest in the production of biofuels. Not only is there some concern about the long-term sustainability of world oil supplies (from fossil fuels), but the very existence of the OPEC cartel tends to make politicians jumpy. They are effectively concerned about “energy security”, in much the same way that they talk about food security. The issue of “green house” gasses, which result from the use of fossil fuels, are becoming a political nightmare. In Africa, economists believe that biofuels projects will provide an opportunity to develop the economies in areas where projects are sited. In his February 2006 state of the nation address President Bush said, “By 2025 we must replace 75% of imported oil by biofuels”. The South African government view is that the country has to produce enough biofuel to contribute up to 75% of its renewable energy by 2013. This shows just how seriously governments are taking the biofuels movement. In the US state and federal resources are available to support the biofuel industry. To this end, fuel blenders are paid 51 US cents per gallon of ethanol added to the fuel mix.

The South African government has done the same and has announced support to the tune of R 6bn (about US$1bn) for the development of a biofuel industry.

Proponents point out that biofuels production in an area results new net economic gain for the region where it is located. These benefits are often over exaggerated. For example, economists claim that biofuel production will create new farming jobs. In developed countries the reality is that farmers are already on the land and may simply swing production from one crop to another (Swenson, 2006). In underdeveloped countries it would probably be true – biofuel projects will create employment.

This discussion will begin by defining exactly what is meant by the term biofuel. In effect, three categories exist. The first is the production of ethanol (bioethanol) from some form of carbohydrate. Companies in South Africa and Brazil have been using sugar cane molasses, the by-product of which is CMS, as a carbohydrate source for this process for years. Recently, the production of ethanol using the starch contained in maize (and other grain) has taken off. The by-product of this process is known as Dried Distillers Grains and Solubles (DDGS). Investors (many of them farmers) are building dozens of new plants in the USA, and South Africa’s first facility is being built at Bothaville.

The second alternative is the production of biodiesel from fats and oils. It is possible to use oil or fat from almost any vegetable or animal source. This would include soybeans, sunflowers, used restaurant grease, and waste animal fat. The British supermarket chain ASDA is investigating turning the fat derived from their chicken roasteries into biodiesel. They may not sell this fat for use in animal feed and shortly they will not be able to dump it in landfills either.

The final means of producing biofuel is by means of biogas production. This entails the production of methane and other gases in simple anaerobic digesters, using animal wastes (manure) as the feedstock. This topic is beyond the scope of this article.

This short article will deal with the production of bioethanol and biodiesel and not biogas production. In broad term the biofuels industry will influence many different areas of both agriculture and the global village and this article will deal with these as well.

The Production of Bioethanol

The production of bioethanol involves using a carbohydrate feeder stock, fermenting it and then removing the resultant ethanol. The by-products that arise are CO2 and some form of solid residue. Each plant is slightly different in terms of the process used, the carbohydrate feedstock and the solid waste generated. Generally when

people talk about bioethanol production, they are referring to the use of maize as the feeder stock for ethanol production.

In broad terms, one ton of grain (maize) yields 420 litres of ethanol, 320 kg of DDGS and 320 kg of CO2.

In order to produce ethanol large amounts of energy, in the form of electricity, coal or gas, are required. In addition the plants have a high demand for water.

Ten to 15% of the revenue stream of a bioethanol plant comes from the sale of the by-products into the animal feed industry (Shurson, 2006).

The Production of Biodiesel

The production of biodiesel is perhaps a much simpler process. Small, do-it-yourself plants are available for a few thousand dollars. Typically, vegetable oil or animal fat are used to produce biodiesel. These are reacted with a solvent (methanol or ethanol) in the presence of a catalyst (sodium hydroxide) to yield glycerine and biodiesel. Standard diesel engines either can utilise biodiesel in its pure form or blended with petroleum diesel. Its physical and chemical properties are similar to petroleum based diesel fuels.

One of the major advantages that biodiesel enjoys over petroleum diesel is biodegradable. In a trial, 95% of biodiesel was degraded within 28 days, whereas only 40% of petroleum diesel was degraded. Interestingly, when 20% biodiesel is added to 80% petroleum diesel the mixture degrades twice as fast as pure petroleum diesel (Biodiesel SA, 2006).

Biodiesel has a flash point (150°C) well above the flash point of petroleum based diesel fuel (± 70°C). This makes it a far safer product to handle.

The use of biodiesel results in a reduction of emissions for diesel engines. The high oxygen content of biodiesel enables more complete combustion than is achieved with petroleum diesel. This leads to a reduction in the solid carbon fraction (particulate matter contained in exhaust emissions) in the exhaust fumes. It also eliminates the sulphate fraction, as there is no sulphur in the fuel. As with all diesel engines there is as increase in nitrous oxide emission.

A 1998 joint study by the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA) traced many of the various costs involved in the production of biodiesel and found that overall, it yields 3.2 units of fuel product energy for every unit of fossil fuel energy consumed.

There are no true waste products produced through biodiesel production, other than glycerol. However, the usual range of oilcakes arises in the production of the oil used in biodiesel production.

Environmental Issues

Managed in sustained manner, biofuels can help reduce the emission of CO2 (greenhouse gases) and other pollutants such as Sulphur. Compared to the use of crude oil, bioethanol reduces CO 2 emissions by 60%. The production from oil from coal (much of South Africa’s fuel is produced in this way) results in five times more CO2 emission than generated by bioethanol.

Biofuel production requires fossil fuel, fertiliser and pesticides. Rather than there being a reduction in greenhouse gas it is often argued that emissions rather increase when using biofuel. However the US Office of Energy Efficiency and Renewable Energy have published data showing that the energy input per unit of ethanol is 0.74 million BTU for each million BTU of energy delivered and that for fossil fuel this figure is 1.23 million BTU for each million BTU of fossil fuel delivered. A large proportion of the energy used in the production of ethanol is “free” solar energy, which needs to be considered as part in then the energy “spend”.

Algae can be used as a feedstock for biodiesel, bioethanol or biogas production. A new South African project will use this technology (Creamer, 2006). Interestingly, the process will make use of CO2 as the feedstock for the algae, and plants will be built near thermal power stations that produce huge amounts of CO2.

There is also a downside of biofuel production. Conservation bodies (Birdlife International for example) are concerned that the increase in demand for grains and pulses for biofuel production will lead to marginal land being put into production, with a consequent loss of important wildlife habitats.

Crop Farming

Grain farmers are interested in biofuel production as a means of boosting the prices that they receive for their crops. In the short term, the reduction in transport costs relative to the point of demand is estimated to be about $2.00 per metric ton in the US. Ironically, higher prices yield lower federal subsidies, so this needs to be borne in mind (Swenson, 2006). Currently 13% of US Maize is used for ethanol production but this is forecast to be nearer to 40% by 2012. The long-term effect of this is that the price of maize could increase by 50% over this period, (Grimes, 2006). This is at odds with the statement by the National Chicken Council (NCC) in January this year. They claim that the mill door price of maize has almost doubled in the past year.

Producers of soybeans and canola are lobbying for an increase for biodiesel production in the hope that they too will enjoy an increase in farm gate prices for their products.

In South Africa, grain farmers are hoping that an established bioethanol industry will reduce the price volatility of maize and that the average price will increase.

Animal Agriculture

Animal agriculture is likely to be effected by the production of biofuels in one of two ways. There will be increased demand for maize, soybeans and sunflower as the feeder stock for alternative fuels. Secondly, the by-products of the biofuels industry, namely DDGS and oilcakes will be available for use in the feed industry. In the short term, supply levels may not be high enough to impact on local ingredient prices, but they are likely to impact on global prices through increasing the global demand.

Oilcakes, the principal by-product of the biodiesel industry, have traditionally been used as a protein source by the animal feed industry. These will not be dealt with here. Thus, it is the use of DDGS in animal feed will be dealt with. Before ingredients can be used, there are a number of considerations. These are; the nutrient content and variability of the ingredient itself; the price and availability of the other ingredients; and lastly, the diet in which it will be used.

The quality of DDGS is highly variable, but with the variation between the different plants being of more significance than the variation that is to found from product produced by a single plant. In short, DDGS contains reasonable protein levels, but what most nutritionists would consider to be low levels of the essential amino acid, lysine. Quality as assessed by amino acid digestibility especially for lysine is variable. On average, true digestibility for lysine was in excess of 70% but some individual samples showed low digestibility (Noll, 2006). What concerns most nutritionists, however, is the possibility of decreased amino acid availability in samples of darker colour. Soybean meal that is over processed exhibits a sharp reduction in lysine availability, so this concern is justified. Research clearly indicates that dark DDGS samples have lower amino acid availability than lighter samples (Dale and Batal, 2005).

Metabolisable Energy (ME) of DDGS was determined on more than 25 samples by the University of Georgia. While samples with higher fibre content understandably have lower energy, a value of 2800 kcal/kg was appropriate for feed formulation. Nick Dale warns that these figures would not apply to products that have had the oil removed for biodiesel production. Many nutritionists have been surprised by the high level of available phosphorus in DDGS. As with other components, the level of total phosphorus is three times higher in DDGS than in maize. It is presumed that during the fermentation process modest amounts of phytase are produced by yeast. This allows for the conversion of phytin phosphorus to more available forms. The phosphorus in DDGS has been found to be approximately 65% available for poultry.

Despite the fact that a lot of research has been conducted on the variability of DDGS from different sources, this does not solve the problem for commercial nutritionists. As with any ingredient, all DDGS will need to be analysed before use and the usual tolerances will need to be applied. It unlikely that DDGS will contain any growth

inhibiting substances (it is maize based after all), but there is a risk that mycotoxins may well be present. These toxins are not destroyed during the ethanol production process.

DDGS has a higher inherent value when used in ruminant diets. The high cost of drying this ingredient, not to mention the energy required for the process, may well mean that feeding wet grains to cattle is the best way to utilise the product. Inclusion rates for wet DDGS can be as high as 30% to 40% of dry-matter intake (DMI) for beef cattle and 20% DMI for dairy. Anything over 20% DMI in dairy, without proper long fibre or forage for balance, can make milk fat percentages fall. Inclusion rates are even lower for pigs, with 10% to 15% being included in grower and finisher rations. Although the industry would like to include more, the upper limit is probably 20% (Shurson, 2006). Poultry diets will probably only ever include up to 10% DDGS and that principally in lower density Layer diets. Broiler performance will be negatively impacted on by the inclusion of low-density ingredients such as DDGS.

Perhaps the biggest impact that the whole biofuels movement will have on animal agriculture has to do with costs. It is probable that input costs into the industry will increase. In addition, it is likely to lead to an increase in the price of the meat and eggs produced. The NCC (2007) estimate that the increase in the maize price has already lead to an increase in the wholesale price of chicken of about 6 cents per pound (almost R 1.00 per kg).

As already mentioned, the cost of maize is likely to rise steadily over the next decade, and it is likely that oilseeds will follow suite. The price of protein into the animal feed industry may well drop. It is believed that there by 2011, the US bioethanol industry will be producing 10 mil short tons more DDGS than can be reasonable used by the animal feed industry. This will result is discounting to the feed industry. If the biodiesel industry takes off in a similar fashion to the bioethanol industry, we may well see a similar pattern arising with regards the other sources of plant protein.

Of interest is glycerine, one of the by-products of biodiesel production. Traditionally it is used in soap and cosmetic manufacture. Supply will probably shortly outstrip demand though. Recent work at the University of Arkansas has shown that this carbohydrate source (it is glycerol after all) can safely be added to the diets of chickens. In a recent study in broiler chickens, it was shown that diets containing 5 percent glycerine supported good performance, but when 10 percent was added to the diets the flow rate of the feed was slightly reduced, hampering feed intake.

Summing Up

The biofuels industry is likely to impact on agriculture more than anything has done in many decades. It is true that some prices will firm, maize in particular, but the possibility that other prices may drop exists. However, it is probably fair to say that input costs in animal agriculture will probably rise because of biofuel production. This will ultimately lead to a rise in the cost of meat and eggs. These will be global trends and it is unlikely that anything us South Africans do will change this.

The by-products of the biofuels industry may well represent an opportunity to nutritionists, but they are certainly not going to be “magic” new ingredients. In broad terms, they are no different to the other ingredients used in the feed industry, namely, quality, consistency and prices will vary. This is something that nutritionists are well versed in dealing with. Unless these ingredients are within acceptable tolerances in terms of their nutrient content and correctly priced, nutritionists will simply not use them.

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