Agriculture Reference
In-Depth Information
capita income predicted to occur in developing
nations such as Africa, China and India (Tilman
et al
., 2002). The demand for high-quality ani-
mal proteins such as meat, milk and eggs
increases concurrently with per capita income,
thus the total food production may have to
increase by 70% by 2050 in order to supply the
global population with a nutritionally adequate
diet (FAO, 2009).
Greenhouse gas (GHG) emissions are often
the focus of environmental sustainability issues,
with a significant amount of media and research
attention being paid to reducing anthropogenic
carbon emissions. However, competition for
resources (including water, land and energy)
between food production and other human activ-
ities may be a more significant issue in the event
of considerable population growth, and the global
livestock industry will face a significant challenge
in producing sufficient animal protein to meet
consumer demand, using a finite resource base.
This issue is not confined to a future scenario -
current concern over dwindling natural resources
and climate change leads to debate as to whether
the livestock industry should continue to inten-
sify and improve productivity to feed the increas-
ing population, or return to less-productive
traditional methods. This chapter will focus on
past, current and future prospects for food pro-
duction sustainability, with a particular focus on
productivity and sustainability within ruminant
livestock systems.
rather than scientific foundation. The FAO (2006)
concluded that intensification of animal pro-
duction was necessary on a global basis to
reduce carbon emissions from livestock systems.
None the less, intensive livestock production sys-
tems may be at the greatest risk from a social
responsibility standpoint, as such systems are
often perceived to be environmentally damag-
ing. Although it is widely understood that
improving efficiency and productivity reduces
expense, resources and waste, the consumer
often considers 'efficiency' to have negative con-
notations when applied to large-scale contempo-
rary food production.
Every animal has a daily nutrient mainte-
nance requirement that must be fulfilled to sup-
port vital functions and minimum activities, and
is independent of whether or not the animal is
actively producing an animal protein product.
For example, a lactating cow produces milk,
whereas a young calf does not, yet they both
have a daily maintenance requirement. The
total maintenance requirement of the livestock
population may be considered as a 'fixed cost' of
animal production. To understand the environ-
mental impact of improved efficiency livestock
production better, an economic metaphor can be
used in which fixed costs are a proxy for popula-
tion maintenance nutrient requirements (Capper,
2011b). Consider a bakery producing bread
with fixed costs of US$1000 (rent, taxes, etc.)
incurred each day, regardless of productivity.
If the factory produces 10,000 loaves per day,
the fixed costs can be divided by the total output
(US$1000/10,000 loaves = US$0.10 per loaf)
and the bread priced accordingly. If the bakery
improves productivity so that 20,000 loaves are
manufactured in the same period, efficiency
improves and fixed costs are spread over greater
output (US$0.05 per loaf). The same concept
can be applied to livestock production and is
known as the 'dilution of maintenance' effect.
Improving productivity such that a greater
quantity of milk, meat or eggs is produced in a
set time reduces the total maintenance cost per
unit of food produced. This directly affects envi-
ronmental sustainability as maintenance nutri-
ents may be considered a proxy for resource use
(including feed, land, water and fossil fuels) and
waste output (e.g. manure and GHG). Improving
productivity consequently reduces resource use
and waste output per unit of food. This rela-
tively simple goal has been the foundation for
The Role of Maintenance Nutrient
Requirements in Environmental
Sustainability
The recent rise of 'ethical consumerism', defined
by Singer and Mason (2006) as 'an interest in
the way in which food is produced, the practices
employed and a concern for low environmental
impact, high animal welfare and optimal worker
conditions', has the potential to significantly
influence the management practices and systems
within livestock production. The mantra that
'the consumer is always right' applies equally to
livestock production as to any other industry, yet
given the amount of misinformation relating to
how food is produced circulating within the
media and popular press, a danger exists that
decisions may be based upon philosophical ideology