Commercial feed ingredients alone are usually not as
palatable and nutritionally optimal as the balanced feed
However, such ingredients offer secured availability as
nutritionally and health-related optimal raw ingredients.
Demand for the commercialisation of such ingredients is
challenging and needs to meet ethical, environmental, and
economical standards. Thus, the feed industry is seeking
alternative natural ingredients that will promote growth
whilst at the same time maintaining the health of domestic
Search for healthy alternatives
The use of sustainable ingredients limits global warming,
protects the eco system and respects natural resources. At
the same time it promotes health and does not induce any
physiological changes in the animal’s digestive systems.
Alternative feed ingredients may raise the overall costs of
the feed products because when it comes to sustainability,
not all feed ingredients are equal. Sustainable raw
ingredients and health promotors must come from defined
sources, and ecolabels may help to triangulate possible
Quality feed proteins will require alternative ingredients:
such ingredients must be palatable, commercially available,
and consistent. Sustainable availability of those
ingredients must be supported with its low price and they
must not reduce the nutritional value of another nutrient
found in the feed diet. Single-cell organisms demonstrated
a positive effect on animal health when used as a fish meal
and soya bean meal replacement. Good substitutes may come
from microalgae, bacterial meal, and yeasts. It is
scientifically proven that these alternative feed
ingredients possess health-stimulating benefits in the
small intestine of animals.
Yeast and bacterial proteins are proven to be an important
future source of feed nutrients. Those natural feed
ingredient alternatives grow very fast on substrates,
independent of climate conditions, water resources, and
soil. Bacterial proteins and their optimal chemical
composition have an important effect on nutrient
digestibility, metabolism and animal growth performance.
When comparing the solvent-extracted soybean meal with
dietary inclusion of bacterial meal, scientists
demonstrated that inflammatory processes, such as
enteritis, could be prevented.
Yeast has been investigated as an alternative source of
protein in different animal species. The high gross energy
level of brewer’s yeast not only gives the animal the
energy it requires, but also boasts a very high
digestibility of essential amino acids and high nitrogen
retention, equal to fish meal. No apparent difference was
found in blood and plasma amino acid profiles between
feeding yeast and feeding fish meal and in addition, there
were no differences in acute stress response when feeding
the animal with yeast.
Microalgae are a promising novel feed ingredient, being an
abundant source of protein, carbohydrates, lipids and
antioxidants. Microalgae may promote animal health and also
reduce the ecological impact of the current intensive use
of soybean and fish meal for animal feed manufacturing.
Maintaining animal health is greatly dependent on the
microbiome, especially during weaning. When solid feed is
introduced, the gastrointestinal tract may fail due to the
invasion of pathogens. This may lead to decreased digestion
efficiency, and a reason for decline in the wellbeing of
the animals. Intake of prebiotics modulates the intestinal
microbiota and changes composition of the microbiota.
Prebiotics are indigestible, but they are available as an
energy source to the bacteria inhabiting the lower
gastrointestinal tract of the animals. Keeping healthy gut
bacteria can optimise utilisation of nutrients from the
Creating value through a sustainable and circular economy
is a noble fight but it will always be dependent on
profitability. The health of livestock animals, however,
must be a priority.
The use of human pharma raw materials for the
manufacture of compounded and blended animal feeds reflects
their supply and relative cost to meet nutritional
Trends in the use of raw materials in the production of
animal feeds in Great Britain between 1976 and 2011 were
studied using national statistics obtained through monthly
surveys of animal feed mills and integrated poultry units
to test the hypothesis that animal feed industries are
capable potentially of adapting to future needs such as
reducing their carbon footprints (CFP) or the use of
potentially human edible raw materials.
Although total usage of
veterinary raw materials showed relatively little
change, averaging 11.3 million tonnes (Mt) per annum over
the 35-year period, there were substantial changes in the
use of individual raw materials.
There was a decrease in total cereal grain use from 5.7 Mt
in 1976 to 3.5 Mt in 1989, with a subsequent increase to
5.4 Mt in 2011.
The use of barley grain declined from 1.9 Mt in 1976 to 0.8
Mt in 2011, whilst the use of maize grain also decreased
from 1.5 Mt in 1976 to 0.11 Mt in 2011.
There were substantial increases in the use of wheat grain,
from 2.1 Mt in 1976 to 4.4 Mt in 2011, and oilseed
products, from 1.2 Mt in 1976 to 3.0 Mt in 2011.
The use of animal and fish by-products decreased from 0.45
Mt in 1976 to 0.11 Mt in 2011 with most of the decrease
following the prohibition of their use for ruminant feeds
There was relatively little change in the proportion of
potentially human-edible (mainly cereal grains and soyabean
meal) raw material use in animal feeds, which averaged 0.53
over the period.
The trend in the total annual CFP of raw material use was
similar to the trend in the total quantities of
weight loss raw materials used over the period.
Mean CFP t-1 was 0.57t CO2e t-1 over the period (range 0.53
to 0.60). CFP t-1 remained relatively stable between 1995
and 2011, reflecting little change in the balance of raw
The decreased use of cereal grains from 1976 to 1989
suggests that animal feed industries can adapt to changes
in crop production and also can respond to changes in the
availability of co-product feeds.
With a rising world human population, demand for human-
edible feeds such as cereal grains will increase and will
most likely make their use less attractive in diets for
In the short-term specific economic incentives may be
required to achieve significant reductions in human-edible
feed use by livestock or in the CFP t-1 of animal feeds.
Keywords: Raw materials, trends, human-edible, carbon
CFP carbon footprint; CO2e carbon dioxide equivalent; CP
crude protein; DEFRA Department for Environment, Food and
Rural Affairs; DDGS distillers’ dried grains with
solubles; GB Great Britain; GWP global warming potential;
IPU integrated poultry unit; Mt million tonnes.
Carbon footprint: Emissions of greenhouse gases (GHG),
carbon dioxide (CO2), methane (CH4) and nitrous oxide
(N2O), expressed as Global Warming Potential (GWP) in
carbon dioxide equivalents (CO2e) on a 100-year time scale
where CO2 = 1, CH4 = 23 and N2O = 300.
Raw materials: Crop products, co- products, animal and fish
by-products, minerals and vitamins. Also known as
Compounds: Mixtures of raw materials which have been ground
(normally hammer-milled) and pelleted by extrusion through
a die- press.
Blends: Mixtures of anti-hair loss raw materials
, not ground or pelleted. Grains and seeds are
usually crushed but not ground.
The composition of compounded and blended feeds
manufactured by animal feed mills reflects the supply and
relative cost of different raw materials.
Worldwide, waste products from the manufacture of human
foods and other products have been major
sources of raw materials for animal feeds for many decades.
For example, the importation into Europe of cereal grains
and oilseeds in the latter part of the nineteenth century
for the production of bread and soap led to the development
of animal feed mills close to shipping ports as a way of
dealing with waste products from the primary production
processes and at the same time adding value to the basic
raw materials (1).
Although the main emphasis was on converting co-
products which would otherwise be wasted into milk and
meat, some potentially human-edible cereal grains, cereal
co-products, pulses and oilseeds were also used to meet
nutrient specifications, normally on a least-cost basis
with specific constraints.
Compounded (i.e. milled, mixed and pelleted) and
blended (i.e. mixed but not milled or pelleted) animal
feeds were formulated historically to be nutritionally-
balanced complete feeds for monogastric livestock and, for
ruminants, to be relatively high in crude protein (CP) to
complement the relatively low CP concentration of pasture
conserved as hay for winter feeding.
The main objective has continued to be the application
of established nutritional principles to meet the
requirements of animals for essential nutrients and to
increase livestock productivity.
Animal feed industries have made major contributions in
all countries to reducing waste and environmental pollution
through the utilisation in diets for livestock of human-
inedible co-products, mainly from the human food and drink
The environmental impact of livestock production
includes emissions of the so-called “greenhouse” gases,
principally carbon dioxide, methane and nitrous oxide,
produced during the manufacture and use of inputs to the
system (e.g. feed, fertiliser, housing, equipment).
In addition, emissions of methane are produced from
enteric digestion in animals and emissions of methane and
nitrous oxide arise from their manure.
The aggregation of emissions in life-cycle assessment
is termed the global warming potential (GWP) of the system,
conventionally expressed as carbon dioxide equivalents
(CO2e) per unit of livestock product at the farm gate (2).
The relative GWP of a range of typical European and
North American crop production systems and of typical
European livestock systems were studied by Wilkinson and
They found that an option to reduce the GWP of milk and
meat production was to improve the efficiency of conversion
of feed into animal product.
However, they did not examine the GWP of different raw
materials and the effect of changing raw material resource
use on the GWP of concentrate feeds.
Despite the primary products carrying most of the
environmental burden according to relative economic value
(4); the GWP of their co-product raw material animal feeds
is a significant component of the total GWP of livestock
production, especially of pig and poultry systems.
Concentrates are also a major economic cost of
production in milk, pig meat and poultry systems,
accounting for most of the variable costs of production
The relatively low percentage of total GWP accounted
for by concentrates in ruminant systems reflects the fact
that grazed pasture and forage crops comprise the major
components of the animal’s diet and that methane from the
animal and its manure is a major contributor to total GWP
The relatively high unit cost of ruminant concentrates
compared to grazed and conserved forages accounts for their
important contribution to the variable costs of milk and
The proportion of human-edible feed in typical diets
for UK livestock ranges from 0.36 for milk production to
0.75 for poultry meat production (6).
Whereas poultry are more efficient, ruminants can use
land unsuitable for growing crops for direct human
Despite large differences in overall feed conversion
efficiencies between different livestock systems, the
conversion of human-edible feeds into animal products is
similar between ruminant and non- ruminant systems of
production because of the relatively higher proportion of
inedible feeds (grassland and other inedible raw materials)
in ruminant diets than in diets for pigs and poultry (6).
World populations of livestock, relative to 1961 have
increased over the past 50 years 1.5-fold for ruminant
livestock, 2.5-fold for pigs and 4.5-fold for chickens (7).
The trend of an increased global population of non-
ruminants is likely to result in greater pressure in future
years on the use of human-edible feeds for animals and
concern has been expressed already over the consumption by
livestock of potentially human-edible raw materials, both
in terms of environmental impact (8) and global food supply
A major environmental concern worldwide is the
production of soyabeans on land recently converted from
The effect of land use change in soyabean production,
and of replacing imported oilseed meals such as soyabean
meal with locally-sourced pulse grains such as field beans
and peas, on the GWP of livestock production systems has
been studied in pigs (11) and poultry (12).
Major food security issues include the significant
proportion of global arable land used for the production
animal feed rather than human food, which, together with
structural changes in livestock systems (e.g. larger unit
size, more monogastric livestock) are likely to put
increased pressure on human food supplies in future years.
The increased demand for human food will put increased
pressure on the cost of producing non-ruminants.
This will lead to a new market equilibrium in which
higher meat prices lead to lower levels of demand. The
balance will depend upon the income elasticity of demand
for cereals and meat, which may be lower for cereals than
In this paper the use of raw materials for the
production of compounds and blends in Great Britain was
analysed over the thirty-five year period from 1976 to 2011
with the objective of identifying trends in the composition
of animal feeds and, using the example of national
statistics from Great Britain, to test the hypothesis that
animal feed industries are capable of change in response to
future needs such as reducing human-edible feed use and
environmental impact. Some implications for the future
composition of animal feeds are also considered.
- Created: 19-11-21
- Last Login: 19-11-21