What's in animal feed

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Harrison's Mill
Harrisons Mill is primarily a feed mill that
produces customized feed for the local farms in
the area. However, Harrisons Mill also has a
farm supply center that also orders farm
machinery, seed, pesticides, herbicides,
insecticides, tack, and other farm
tools. Harrisons utilizes modern technology
while maintaining an old-fashioned sense of
community. Employees of Harrisons still hand
deliver products to the local farms and help run
field tests to determine crop and animal
needs. The owner of Harrisons, William Dolittle,
bought the mill from the Harrison family 10 years
ago but the contract specifically stated that Mr.
Dolittle had to keep the name and hands-on
practices intact for a minimum of 15 years or
until the last member of the Harrison family
died, whichever came first. Only one member of
the Harrison family survives and that is the wife
of Mr. Carl Harrison, the former owner of the
mill. Carl died of cancer in 1999.
What's in animal feed? Ingredients are often
added to the food of animals in factories to make
them grow faster and larger, or for other
reasons. Many of these additives are substances
that could have damaging effects on people if
they are consumed. Most governments regulate the
maximum level of residues of additives that are
allowed in food for human consumption.
Antibiotics For the last few decades, many
farmers have been feeding animals (particularly
chickens and pigs) low doses of antibiotics
routinely in their feed or water, because it was
found that this increased the animals growth
rate. It also protects them against diseases
which can be passed between animals kept in
overcrowded conditions. Parasite
control Poultry kept together in large numbers
are a breeding ground for internal parasites
called coccidia, which cause diarrhoea. To
prevent this, medicines (known as coccidiostats)
are often put in the animals feed in factory
farms to control the parasites. Residues of
coccidiostats can contaminate the animals meat.
Some of these substances are toxic to humans and
are only allowed to be present in the meat in
very low quantities. However, in the UK in 1999
it was found that 17.8 per cent of chicken livers
tested had residues of coccidiostats in excess of
the maximum residue limit of 200 micrograms per
kg, the highest residue found being 50 times the
permitted level. Sometimes feed can become
contaminated with illegal additives accidentally,
for example at feed mills or in farmers stores.
In the UK, the potentially toxic coccidiostat
lasalocid is banned for feeding to laying hens,
because of the possibility that it can
contaminate eggs. In spite of the ban, in 2003
the UKs regulators found that residues of
lasalocid in eggs were five and a half times
higher than in the previous year, presumably due
to accidental or careless contamination of the
hens feed.
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Chemical additives Many intensive farms use
animal fat to supplement the feed given to
animals such as chickens and farmed fish. Because
some toxic chemicals, such as polychlorinated
biphenyls (PCBs), dioxins and organochlorines,
accumulate in the fatty tissue of animals they
can be passed to humans who eat animals that have
eaten the fat-supplemented feed. These chemicals
are known as Persistent Organic Pollutants (POPs)
and they have been associated with health
problems in humans such as damage to the nervous
or immune system and reproductive problems. In
Belgium in 1999, animal fat intended for animal
feed contaminated over 15,000 tonnes of animal
feed with toxic levels of PCBs and dioxins,
resulting in the withdrawal of chicken meat and
eggs from the market. Intensively farmed salmon
contains 11 times more dioxin than wild salmon,
leading some experts to recommend that people
should limit how much salmon they consume.
Arsenic Arsenic-based feed additives are given
to pigs and poultry in some countries in order to
increase their weight. Some of the arsenic
compound is excreted in the chickens faeces, but
some is retained in the chickens' liver. Chicken
meat in the US contains three to four times as
much arsenic as other types of meat. Hormones Gro
wth hormones are given to cattle as implants or
as injections to increase their growth rate or
their milk production. In the US, 90 per cent of
beef cattle and one third of dairy cows are
treated with growth hormones. The possibility of
the hormones affecting consumers has caused great
concern, because these hormones have been linked
to cancer and other health problems. Because of
medical and public concern, the EU has banned the
sale of hormone-treated beef, but it is known
that such meat is still sold illegally and
residues of at least 35 drugs have been found in
meat samples in the EU. Colourants Canthaxanthin
is a yellow/orange colourant which can be put
into the feed of chickens and factory farmed
salmon in order to brighten the colour of egg
yolks and chicken or salmon flesh. It is
originally found in plants, but the substance
used for animal feed is usually synthetically
made. Because it can have damaging effects on
humans at high doses, governments usually set
legal limits to the amount of canthaxanthin that
is allowed to be used in animal feed, based on a
maximum safe dose for humans. In 2002, the EUs
Scientific Committee on Animal Nutrition
expressed the view that some consumers of poultry
or salmon might be unknowingly eating more than
the acceptable daily dose of canthaxanthin.