Agriculture Reference
In-Depth Information
physiological states were established fairly well
(e.g. NRC, 2001). In developed countries there
are a number of computerized systems employed
to evaluate and formulate rations for both non-
ruminants and ruminants and to match ani-
mals' nutrient and energy requirements to
locally available feedstuffs. Current incremental,
fine-tuning research largely is focused on refin-
ing these systems and building more under-
standing of the more mechanistic and dynamic
nature of feed intake, digestion, rumen micro-
bial protein production, tissue nutrient metabo-
lism and animal performance.
A significant body of work remains to be
completed better to establish the relationships
among animal performance, body and milk
composition, feed needs and quality, the excre-
tion of nutrients and energy from animals, and
the consequent production and environmental
costs upstream and downstream of the single
farm (sub-) system and regional aggregate of
farms. This more holistic work is and will help
improve the whole-farm net efficiency for cap-
ture of nutrients and energy by animals and
help facilitate understanding and establish real-
istic expectations for consumers of what is pos-
sible and probable, and provide guidance for
legislative and regulatory agencies.
In spite of the increased knowledge and
application of nutrition advances in developing
countries, the vast majority of the world's ani-
mals, and particularly ruminants in pastoral
and extensive mixed plant-animal systems in
most developing countries, experience episodic
or permanent nutrient and energy shortages
(Bruinsma, 2003). Poor animal nutrition, even
before genetic potential, is likely the primary
limitation in small farms in developing countries.
Considerable research has been done to improve
forage quality (digestibility), availability and
preservation, use of trees and crop residues and
use of dietary nutrient supplementation for
animals. Because various sorts of mixed plant-
animal systems are very common in many parts
of the world, better integration and manage-
ment of nutrient and energy cycles most likely
can improve animal productivity and enhance
soil fertility (McIntire
et al
., 1992). Nutrients
and energy serve multiple purposes as food, feed
and fertilizer. In developing countries there
would seem to be opportunities to intensify
practices and management of inputs and tools
derived from more high-input systems in devel-
oped countries. Similar mixed plant-animal
systems have been and still are predominant
and successful in many farms in developed
countries.
Other factors likely will weigh more heavily
on improvement of animal nutrition in the
future. At the forefront is the continuing goal to
improve feed conversion efficiency (VandeHaar
and St-Pierre, 2006; Chapter 2 and 3). The ever-
continuous volatility of margins for farmers
doubtless will be greatly affected by swings
in feed and energy prices. Thus, improved feed
conversion efficiency is one approach to help
achieve profitability in animal production.
Increased public awareness and concerns about
the use of feed antibiotics in animal agriculture
will become increasingly important also (Vallat
et al
., 2005). The global trend was set in 2006 to
reduce use with removal of all growth-promoting
antibiotics from animal feeds in the European
Union (HCPC, 2005). Some other developed
countries likely will follow with similar actions
in the future. Other exogenous chemical com-
pounds (e.g. hormones influencing growth or
reproduction) likely will be examined carefully
and may have similar fates over time. In other
cases, the precautionary principle simply may be
employed until such time and resources can be
invested to quantify relative risk and safety of
any new or existing technology or performance-
enhancing compounds (Recuerda, 2008). The
vastly increasing globalization of markets for
animal products (Chapter 12) will have major
influence to heighten awareness and concerns
about use of exogenous chemicals, food safety
and food quality, and to affect the sustainability
of animal agriculture in various regions.
Another key influencer affecting delivery of
animal nutrition will be the need and (or) legal
obligation to reduce air emissions (e.g. ammonia
and greenhouse gases) originating from animal
farms. Improved feeding practices (e.g. improved
digestibility of forage fibre by earlier harvesting
or the use of more highly digestible concentrate
feeds) reduce enteric methane emissions.
Reducing methane emissions per unit of edible
animal product will be a key reference standard
within and across animal species, animal agri-
culture system types and countries in the future.
A significant effort is underway worldwide to
discover potential dietary chemicals (including
