WORLD FOOD SUPPLY (contd.)

FOOD FROM ANIMAL FEED

It takes, on average, 3 kg of grain to produce 1 kg of meat, given that part of the production is based on other sources of feed, rangeland and organic waste (FAO, 2006). Currently, 33 % of the cropland area is thus used for livestock (FAO, 2006 livestocks long shadow). In addition, about 16,000 litres of virtual water are needed to produce 1 kg of meat (Chapagain and Hoekstra, 2008). Hence, an increased demand for meat results in an accelerated demand for water, crop and rangeland area. Meat production is energy inefficient and environmentally harmful at industrial scales and with intense use of feed crops such as maize and soybeans. Chicken production is among the most energy-efficient, although still more energy-demanding than cereal production. Many farmers feed their animals organic waste from farm households or agricultural by-products that are unsuitable for human consumption. Small-scale pig farms often use organic residuals from restaurants and the food industry as fodder. If animals are part of an integrated farm production system, the overall energy efficiency can be actually increased through better utilization of organic waste (CTech, 2008). This is not the case for mass production of pigs and poultry in specialized stables, which may take up an increasingly larger proportion of the production of feed crops (Keyzer et al., 2005). 

It is also important to note that much meat production takes place on extensive grasslands. But while often a threat to biodiversity and a source of competition with wild ungulates and birdlife (UNEP, 2001; FAO, 2008b), this requires very little or no input of commercial feed. Furthermore, it plays a crucial role in food security in many mountain areas, as well as in dry and steppe regions, including in Africa, Central Asia and the Andes.

Stabilizing the current meat production per capita by reducing meat consumption in the industrialized world and restraining it worldwide to 2000 level of 37,4 kg/capita in 2050 would free estimated 400 million tons of cereal per year for human consumption – or enough to cover the annual calorie need for 1.2 billion people in 2050. However, changing consumption patterns may be very difficult in the short-term. Increasing food supply by developing alternatives to cereals and improving feed efficiency in commercial feed may however have a much greater potential for increasing food supply (See box).

FINDING ALTERNATIVE FEED SOURCES 

Choice of food – where choice exists – is a complex mix of traditions, religion, culture, availability and not the least, financial constraints. However, while many of these also apply to livestock, our ability to change the feed destined for livestock and aquaculture is probably greater than that of changing people’s food choice habits, which are not as easily controlled. As cereal products are increasingly used as feed for livestock, estimated to be at least 35–40% of all cereal produced in 2008 and projected to reach nearly 45–50% by 2050 if meat consumption increases (adapted from FAO, 2003; 2006), finding alternative feed sources provides a huge potential for increasing the availability of cereal for human consumption. For other feed sources to become a sustainable alternative to the current use of cereals, their exploitation must not be resource-demanding. This poses a big challenge, since most of the easily available feed sources have already been fully exploited, although some alternatives still exist. 

Cellulose is the most abundant biological material in the world, but the energy it contains is not readily available for animal production. Due to the interest in using this material for bioethanol production, there are currently large research programs underway to chemically and enzymatically degrade this cellulose into glucose. If this becomes possible and in a cost-effective manner, wood glucose can, to a large extent, replace cereals as a feed source for both ruminants and monogastric animals. Other fibrous plant sources such as straw, leaves and nutshells are also available in large quantities. Finding ways to feed the world’s livestock is therefore a primary challenge (Keyzer et al., 2005).

Other sources for feed that are not fully exploited include seaweed, algae and other under-utilized marine organisms such as krill. However, their potential is uncertain, since technological challenges still remain. In addition, the impact of their harvesting on the ecosystem is of concern. The use of waste provides a much greater potential for alternative sources of animal feed.

How many people can be fed with the cereals allocated to animal feed?

By 2050, 1,573 million tonnes of cereals will be used annually for non-food (FAO, 2006a), of which at least 1.45 million tonnes can be estimated to be used as animal feed. Each tonne of cereal can be modestly estimated to contain 3 million kcal. This means that the yearly use of cereals for non-food use represents 4,350 billion kcal. If we assume that the daily calorie need is 3,000 kcal, this will translate into about 1 million kcal/year needed per person.

From a calorie perspective, the non-food use of cereals is thus enough to cover the calorie need for about 4.35 billion people. It would be more correct to adjust for the energy value of the animal products. If we assume that all non-food use is for food-producing animals, and we assume that 3 kg of cereals are used per kilogram animal product (FAO, 2006b) and each kilogram of animal product contains half the calories as in one kg cereals (roughly 1,500 kcal per kg meat), this means that each kilogram of cereals used for feed will give 500 kcal for human consumption. One tonne cereals used for feed will give 0.5 million kcal, and the total calorie production from feed grains will thus be 787 billion kcal. Subtracting this from the 4,350 billion calorie value of feed cereals gives 3,563 billion calories.

Thus, taking the energy value of the meat produced into consideration, the loss of calories by feeding the cereals to animals instead of using the cereals directly as human food represents the annual calorie need for more than 3.5 billion people.

FOOD - OR FEED - FROM WASTE

By using discards, waste and other post-harvest losses, the supply of animal and fish feed can be increased and be sustained without expanding current production, simply by increasing energy efficiency and conservation in the food supply chain.

There has been surprisingly little focus on salvaging food already harvested or produced. An important question centers around the percentage of food discarded or lost during harvesting, processing, transport and distribution as well as at the point of final sale to consumers. Reducing such losses is likely to be among the most sustainable alternatives for increasing food availability.

Discarded fish from marine fisheries is the single largest proportion lost of any food source produced or harvested from the wild. The proportion is particularly high for shrimp bottom trawl fisheries. Mortality among discarded fish is not adequately known, but has, for some species, been estimated to be as high as 70–80%, perhaps higher (Bettoli and Scholten, 2006; Broadhurst et al., 2006). Discarded fish alone amounts to as much as 30 million tonnes, compared to total landings of 100–130 tonnes/year. Feed for aquaculture is a major bottleneck, as there are limitations to the available oil and fish for aquaculture feed (FAO, 2008). A collapse in marine ecosystems would therefore have a direct impact on the prices of aquaculture products and on its scale of production. There is no indication that marine fisheries today can sustain the 23% increase in landings required for the 56% growth in aquaculture production required to maintain per capita fish consumption at current levels to 2050. However, if sustainable, the amount of fish currently discarded at sea could alone sustain more than a 50% increase in aquaculture production. However, many of these species could also be used directly for human consumption.

Fish post-harvest losses are generally high at the small-scale level. Recent work in Africa by FAO has shown that regardless of the type of fisheries (single or multi-species), physical post-harvest losses (that is, fish lost for human consumption) are commonly very low, typically around 5% (DieiOuadi, 2007). Downgrading of fish because of spoilage is considerable, however, perhaps as high as 10% and more. Hence, the total amount of fish lost through discards, post-harvest loss and spoilage may be around 40% of landings (DieiOuadi, 2007).

The potential to use unexploited food waste as alternative sources of feed is also considerable for agricultural products. (Figures 11 and 12).

Food losses in the field (between planting and harvesting) could be as high as 20–40% of the potential harvest in developing countries due to pests and pathogens (Kader, 2005). Postharvest losses vary greatly among commodities and production areas and seasons. In the United States, the losses of fresh fruits and vegetables have been estimated to range from 2% to 23%, depending on the commodity, with an overall average of about 12% losses between production and consumption sites (Cappellini and Ceponis, 1984; Harvey, 1978; Kader, 2005). Kantor et al (1999) estimated the U.S. total retail, foodservice, and consumer food losses in 1995 to be 23% of fruits and 25% of vegetables. In addition, losses could amount to 25–50% of the total economic value because of reduced quality (Kader, 2005). Others estimate that up to 50% of the vegetables and fruits grown end as waste (Henningsson, 2004). Finally, substantial losses and wastage occur during retail and consumption due to product deterioration as well as to discarding of excess perishable products and unconsumed food. While the estimates therefore vary among sources, it is clear that food waste represents a major potential, especially for use as animal feed, which, in turn, could release the use of cereals in animal feed for human consumption.

In 2007, US$148 billion was invested in the renewable energy market, up 60% from the previous year. Recovering energy from agricultural wastes is becoming increasingly feasible at the industrial production level; investments in technology enhancement of existing systems and innovation in new waste management systems is called for to support this expanding green economy.

 

Increasing food supply by reducing food waste

By 2050, 1,573 million tonnes of cereals will be used annually for non-food (FAO, 2006a), of which at least 1.45 million tonnes can be estimated to be used as animal feed. Each tonne of cereal can be modestly estimated to contain 3 million kcal. This means that the yearly use of cereals for non-food use represents 4,350 billion kcal. If we assume that the daily calorie need is 3,000 kcal, this will translate into about 1 million kcal/year needed per person.

From a calorie perspective, the non-food use of cereals is thus enough to cover the calorie need for about 4.35 billion people. It would be more correct to adjust for the energy value of the animal products. If we assume that all non-food use is for food-producing animals, and we assume that 3 kg of cereals are used per kilogram animal product (FAO, 2006b) and each kilogram of animal product contains half the calories as in one kg cereals (roughly 1,500 kcal per kg meat), this means that each kilogram of cereals used for feed will give 500 kcal for human consumption. One tonne cereals used for feed will give 0.5 million kcal, and the total calorie production from feed grains will thus be 787 billion kcal. Subtracting this from the 4,350 billion calorie value of feed cereals gives 3,563 billion calories.

Thus, taking the energy value of the meat produced into consideration, the loss of calories by feeding the cereals to animals instead of using the cereals directly as human food represents the annual calorie need for more than 3.5 billion people.

 

 
Figure 11: Food losses for different commodities. (Source: Kantor et al., 1999). Figure 12: A gross estimate of the global picture of losses, conversion and wastage at different stages of the food supply chain. As a global average, in the late 1990s farmers produced the equivalent of 4,600 kcal/capita/day (Smil, 2000), i.e., before conversion of food to feed. After discounting the losses, conversions and wastage at the various stages, roughly 2,800 kcal are available for supply (mixture of animal and vegetal foods) and, at the end of the chain, 2,000 kcal on average – only 43% of the potential edible crop harvest – are available for consumption. (Source: Lundqvist et al., 2008).

 

Sustainable food supply

The discourse around food and agriculture that has dominated the past 60 years needs to be fundamentally re-thought over the next few years. New strategies are needed that respond to the daunting challenges posed by climate change mitigation and adaptation, water scarcity, the decline of petroleum-based energy, biodiversity loss, and persistent food insecurity in growing populations. A narrowly-focused ‘seed and fertilizer’ revolution will not avert recurrent food crises under these conditions; current models of intensive livestock production will be unaffordable; global and national food supply chains will need to be restructured in light of demographic shifts and increasing fuel costs. Future food production systems will not only depend on, but must contribute positively to, healthy ecosystems and resilient communities. Soils and vegetation in agricultural landscapes must be restored and managed in ways that not only achieve food security targets far more ambitious than those committed to under the Millennium Development Goals, but also provide watershed services and wildlife habitat, and sequester greenhouse gases.

 

Other key facts and figures on food waste and losses

United States of America: In the United States 30% of all food, worth US$48.3 billion (€32.5 billion), is thrown away each year. It is estimated that about half of the water used to produce this food also goes to waste, since agriculture is the largest human use of water. Losses at the farm level are probably about 15–35%, depending on the industry. The retail sector has comparatively high rates of loss of about 26%, while supermarkets, surprisingly, only lose about 1%. Overall, losses amount to around US$90 billion–US$100 billion a year (Jones, 2004 cited in Lundqvist et al., 2008).

Africa: In many African countries, the post-harvest losses of food cereals are estimated at 25% of the total crop harvested. For some crops such as fruits, vegetables and root crops, being less hardy than cereals, post-harvest losses can reach 50% (Voices Newsletter, 2006). In East Africa and the Near East, economic losses in the dairy sector due to spoilage and waste could average as much as US$90 million/year (FAO, 2004). In Kenya, each year around 95 million litres of milk, worth around US$22.4 million, are lost. Cumulative losses in Tanzania amount to about 59.5 million litres of milk each year, over 16% of total dairy production during the dry season and 25% in the wet season. In Uganda, approximately 27% of all milk produced is lost, equivalent to US$23 million/year (FAO, 2004).

Asia: Losses for cereals and oil seeds are lower, about 10–12%, according to the Food Corporation of India. Some 23 million tonnes of food cereals, 12 million tonnes of fruits and 21 million tonnes of vegetables are lost each year, with a total estimated value of 240 billion Rupees. A recent estimate by the Ministry of Food Processing is that agricultural produce worth 580 billion Rupees is wasted in India each year (Rediff News, 2007 cited in Lundqvist et al., 2008).

Europe: United Kingdom households waste an estimated 6.7 million tonnes of food every year, around one third of the 21.7 million tonnes purchased. This means that approximately 32% of all food purchased per year is not eaten. Most of this (5.9 million tonnes or 88%) is currently collected by local authorities. Most of the food waste (4.1 million tonnes or 61%) is avoidable and could have been eaten had it been better managed (WRAP, 2008; Knight and Davis, 2007). Australia: In a survey of more than 1,600 households in Australia in 2004 on behalf of the Australia Institute, it was concluded that on a country-wide basis, $10.5 billion was spent on items that were never used or thrown away. This amounts to more that $5,000/ capita/year.

Environmental impacts of food waste The impact of food waste is not just financial. Environmentally, food waste leads to: wasteful use of chemicals such as fertilizers and pesticides; more fuel used for transportation; and more rotting food, creating more methane – one of the most harmful greenhouse gases that contributes to climate change. Methane is 23 times more potent than CO2 as a greenhouse gas. The vast amount of food going to landfills makes a significant contribution to global warming. WRAP (Waste and Resource Action Program), a UK based group, estimates that if food were not discarded in this way in the UK, the level of greenhouse gas abatement would be equivalent to removing 1 in 5 cars from the road (WRAP, 2007).

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