Agriculture Reference
In-Depth Information
3
Production Efficiency of
Monogastric Animals
H.D. Poulsen,
1
* K. Blaabjerg,
1
J.V. Nørgaard
1
and E. Kebreab
2
1
Department of Animal Science, Research Group on Animal Nutrition and
Environmental Impact, Aarhus University, Foulum, Denmark;
2
Department of
Animal Science, University of California, Davis, California, USA
Introduction
production is therefore mainly caused by an
increased cropping intensity and yield partly
due to increased access to inorganic fertilizers
(Erisman
et al
., 2011). According to Steinfeld
et al
. (2006), feed production is estimated to
use about one-third of all cropland, and the
demand for animal feed will increase along
with the expansion in the number of livestock.
In the past, livestock production was directly
related to access to arable land, but the indus-
trialized animal production has in many cases
been decoupled from crop production at a local
or even regional scale. This is challenging to
the modern industrialized animal production
and calls for improvements in production effi-
ciency in order to improve the utilization of
nutrients and to lower the impact of animal
production on the environment.
This chapter deals with ways to improve the
production efficiency and reduce the excretion
of primarily nitrogen (N) and phosphorus (P),
but also other undesired substances such as
heavy metals in monogastric animals and emis-
sions of ammonia and methane. Two main areas
will be addressed: (i) the amount of feed required;
and (ii) the concentration and quality of nutri-
ents in the provided feed. The first topic focuses
on how much feed the animal requires for the
The number of farm animals has enormously
increased over the last few decades globally to
meet the increased demands for animal prod-
ucts caused by the expanding world popula-
tion (FAO, 2011). It is forecasted that the
demand for meat will increase by more than
70% along with the increase in population
size to more than 9 billion in 2050 (United
Nations Population Division, 2010). This is
expected to cause a more intensified animal
husbandry as the arable land area will not
increase accordingly.
Over the last 100 years, land use has
changed dramatically as the percentage of total
land area used for cropland and pasture has
expanded at the expense of natural habitats
(Steinfeld
et al
., 2006). The development in
production of monogastric animals is closely
related to these changes in land use as it relies
on the production of cereals and protein crops
(Steinfeld
et al
., 2006). Since 1960, the produc-
tion of soybeans and cereals has increased
three- to tenfold concomitantly with an
increase in soybean harvest area of about
threefold and a stagnation in cereal harvest
area (Steinfeld
et al
., 2006). The increased crop
