renderers process ends up right back on the farm or ranch.
NARA’s website explains: “In fact, the industry returns the
majority of its finished products to the feed industry in the
form of high-energy fats and high-quality protein ingredients
that supplement the diet and enable efficient production of
beef, veal, pork, poultry, fish, eggs, and milk. The pet food
industry also benefits by having access to a vast array of
nutrient-rich and flavorful ingredients for rations that maintain
healthy companion animals.”
It is not just the recycling of by-products that increases
livestock and poultry sustainability. The fats and proteins
recovered through rendering, then added to feed, help to
lower costs of livestock production. For example, adding fat to
beef cattle rations increases average daily gain and efficiency of
feed utilization. It also improves absorption of other nutrients,
boosts the metabolizable energy of the diet, and counteracts
heat stress.
In swine, supplementary fat increases energy density,
lowers feed cost per sow, and enhances weaning weights,
according to NARA. In addition, supplemental fat can help
dairy cows maintain body weight during early lactation when
energy intake is key to milk production.
Rendered products are also a crucial source of valuable
nutrients in feedstuffs for poultry. They provide essential fatty
acids to help increase egg weight, and offer much-needed
protein for larger bird growth.
“We’re kind of joined at the hip because most all of our
raw material supplies depend on the growth and health of
the livestock industry,” said Dr. David Meeker, NARA’s senior
vice president of scientific services. “Because so much of
animal feed and pet food ingredients are made from these
by-products, rendering helps make those industries more
sustainable because they don’t have to use human food or
virgin ingredients to produce their products.”
Meeker also pointed to an obvious benefit that livestock
producers think of when envisioning what renderers do.
“It’s probably a little bit smaller impact because death loss
on farms is a small percentage, but all the major livestock areas
have rendering services that pick up fallen animals, animals
that break a leg or don’t make it to market,” he explained.
“Those carcasses are then processed into proteins and fats
for fuel and all kinds of other products. It contributes to the
sustainability of those production units by preventing those
losses from being wasted.”
Collecting deadstock is also a critical control point from
an environmental standpoint for a few reasons:
• Diverting dead livestock to a rendering facility instead
of burial or composting reduces the possibility of
disease spread through rodents and other wildlife.
Decomposition can provide a breeding ground for
harmful pathogens like Salmonella and E. coli.
• The strictly regulated rendering process uses high
temperatures to kill off any pathogens, making the
by-products safe and reusable.
• Natural decomposition involves emissions of carbon
dioxide, methane, and other greenhouse gases
(GHG). NARA data shows that rendering animal
tissues is the GHG reduction equivalent to removing
18.5 million cars off the road each year.
Water Recovery
The rendering process also helps capture and reuse
water that might otherwise have been wasted. According
to the Darling green paper, meat by-products are composed
of 60 percent water. After the raw material is cooked and
any pathogens are killed, that water is extracted before the
renderer separates out the fat and proteins. The water is then
used to help clean the plant or returned to the municipal water
supply for further treatment.
All in all, United States renderers evaporate four billion
gallons of water annually. The capture and reuse of that water
should count toward the sustainability of livestock and poultry.
Green Energy and New Applications
If anything screams sustainability, it is reducing the use
of fossil fuels. One fast-growing market for green energy
utilizes two upcycled by-products—animal fats and UCO from
restaurants. Biodiesel and renewable diesel are two green
energy products made possible by utilizing rendered products;
an estimated 13 percent of these biofuels are produced with
animal fats. These biofuels are recycled, renewable, and add
to both industries’ sustainability credentials.
There are many new applications for livestock and poultry
by-products being developed now that will add even more
benefits to society.
Dr. B.J. Bench, senior director of food safety and quality
assurance at Tyson Foods Inc.’s Ingredient Solutions Group,
points to the sustainability of using poultry products versus
fish in aquafeed.
“Various fish species harvested for fishmeal are not
a sustainable source for aquaculture feeds,” he explained.
“That is why aquaculture nutritionists are looking at replacing
a certain percentage of diets utilizing fish meal with other
rendered products. For example, chicken by-product meal has
a very similar amino acid profile to fish meal, allowing it to be
more readily used as an alternative feed ingredient.”
Meeker said research funded by the Fats and Proteins
Research Foundation is underway on how rendered proteins
and fats can be used in soil remediation and the cleanup of
Superfund sites. Other research focuses on lower-quality
rendered material that could be used to make cement and
building materials that are much more sustainable.
“Actually, they perform better as well,” Meeker stated.
“They’re tougher and stronger and more sustainable than
cement. So, we can take these low-quality fatty acids and
combine them with surplus sulfur creating a replacement for
both cement and asphalt.” He added that, in the future, some
of these products will likely be used to make roads, parking
lots, and buildings.
“Those are some of the things that not only are we working
on, but that we’re also trying to make sure policymakers are
aware of so the rendering and animal agriculture industries
can be viewed as part of the solution to climate change and
overall sustainability,” Meeker said.
As the livestock and poultry industries seek to tell
their sustainability story to consumers and legislators alike,
the benefits they reap from rendering—economically and
environmentally—should be included. Otherwise, the rest of
the story is missing. R
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