In this paper, researchers from universities in Switzerland, Italy, Austria, the UK and Germany investigate the potential for feeding livestock on less food-competitive feedstuffs (FCF – that is, animal feed derived from fewer human edible food sources) to reduce the negative environmental impacts of livestock farming.
The authors begin by describing the various approaches that have been proposed for improving livestock sustainability:
- improving the efficiency of livestock production through breeding and feeding reformulations;
- reducing demand for animal products; and
- reducing the use of food-competing feed components in livestock rations
(NOTE: the FCRN has written extensively on different framings and stakeholder approaches to improving livestock sustainability. See in particular Gut Feelings , which in somewhat science-fiction mode describes four different livestock scenarios) and Lean, green, mean, obscene, which looks at how different interpretations of the word efficiency influence ideas about what a sustainable livestock system looks like; as well as these journal articles http://www.fcrn.org.uk/fcrn/publications/three-perspectives-sustainable-food-security and http://www.fcrn.org.uk/fcrn/publications/food-sustainability-problems-perspectives-and-solutions).
The focus of the study here is on the third strategy, which they term the ‘consistency’ strategy. This approach seeks to avoid feeding livestock on grains and crops that could be eaten directly by humans. Instead, livestock are to be raised on the following feed sources:
- grasslands, which cover two-third of global agricultural area and can be used for food production by ruminants, whereas a large proportion of these grasslands is not or less suitable for arable crop production and
- food waste and by-products of food production–consumption chains, such as brans, whey and oil-cakes.
Fodder crops grown on arable land and concentrate feed derived from human edible food (e.g. grains, pulses) grown on arable land are not eligible.
The researchers model the effects of such a strategy on patterns of crop and livestock production and human diet, and on key environmental indicators, including land and water use, greenhouse gas emissions, fertiliser use and pesticide surpluses.
They acknowledge that their model does not include or account for market effects, and that it should not therefore be treated as a forecasting tool. Note that – unlike the recent article in Nature Climate Change by de Silva et al – the model does not incorporate the possibility of improvements in grassland productivity that in turn would increase livestock productivity and would lead to soil carbon sequestration, thereby offsetting direct emissions in the form of methane and nitrous oxide.
The researchers construct a range of ‘food – not feed’ scenarios for 2050 which differ in the extent to which they adhere completely to the food not feed principle (from 0% to 100%). They then compare these against a reference scenario based on the FAO’s agricultural projections.
They find that compared with the base year (i.e. the situation today) zero use of food competing foodstuffs would result in:
- 335 Mha decrease in arable land area, which corresponds to a decrease of 22% in arable and 7% in the total agricultural area.
- The number of cattle reared would increase by 4% compared with the base year, and by 60 million, i.e. 4% compared with the base year, and by 37%, 22% and 44% for goat, sheep and buffalo respectively, as these animals are mainly fed on grasslands. The numbers would, however be lower than in the reference business as usual (BAU) scenario, with the exception of buffalo.
- By contrast, poultry numbers would decline by 70% and pigs by 88%, since these animals are highly dependent on arable based feeds.
Since the human population is growing, the increase in absolute production would not in fact lead to an increase in absolute consumption – on the contrary (see the Table 2 in the paper). Per capita intakes would fall as follows:
- Milk -43%,
- Non ruminant meat -91%,
- Eggs -90%
- Fish (aquaculture systems are often feed dependent) -30%
- Ruminant meat -43%.
If energy levels in the human diet are kept constant, the share of energy delivered through protein would change from today’s 10.8% to 10.3% - which (although the authors do not discuss this) is at the very lowest end of human protein recommendations (see for example here). The share of livestock products in the total protein supply would drop from 38% to 11%
As the useful infographic below, copied from the paper, shows, zero use of food competing foodstuffs would deliver substantial environmental improvements across a range of indicators as compared with the reference scenario (i.e. business as usual in 2050), and small improvements as compared with the base year with the exception of freshwater use.
Increasing efficiency in livestock production and reducing the share of animal products in human consumption are two strategies to curb the adverse environmental impacts of the livestock sector. Here, we explore the room for sustainable livestock production by modelling the impacts and constraints of a third strategy in which livestock feed components that compete with direct human food crop production are reduced. Thus, in the outmost scenario, animals are fed only from grassland and by-products from food production. We show that this strategy could provide sufficient food (equal amounts of human-digestible energy and a similar protein/calorie ratio as in the reference scenario for 2050) and reduce environmental impacts compared with the reference scenario (in the most extreme case of zero human-edible concentrate feed: greenhouse gas emissions -18%; arable land occupation -26%, N-surplus -46%; P-surplus -40%; non-renewable energy use -36%, pesticide use intensity -22%, freshwater use -21%, soil erosion potential -12%). These results occur despite the fact that environmental efficiency of livestock production is reduced compared with the reference scenario, which is the consequence of the grassland-based feed for ruminants and the less optimal feeding rations based on by-products for non-ruminants. This apparent contradiction results from considerable reductions of animal products in human diets (protein intake per capita from livestock products reduced by 71%). We show that such a strategy focusing on feed components which do not compete with direct human food consumption offers a viable complement to strategies focusing on increased efficiency in production or reduced shares of animal products in consumption.
Schader, C., Muller, A., Scialabba, N.E.-H., Hecht, J., Isensee, A., Erb, K.-H., Smith, P., Makkar, H.P.S., Klocke, P., Leiber, F., Schwegler, P., Stolze, M., and Niggli, U. (2015) Impacts of Feeding Less Food-Competing Feedstuffs to Livestock on Global Food System Sustainability. Journal of The Royal Society Interface 12 (113), 20150891.
See the full article here and further coverage here.
You can find related resources in the Research Library categories on primary production: agriculture, animal issues, meat, as well as the keywords categories on animal feed, sustainable healthy diets, consumption and production trends, grazing and land use.
See also our summary of another recent paper, Call for conservation: abandoned pasture, as well as our summary of the paper by De Oliviera Silva et al. For another paper discussing similar questions, see Elin Röös’ paper which she recently blogged about on the FCRN website.
03 Feb 2016
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