Ruminant Nutrition Notes
Extension Animal Husbandry
Department of Animal Science
North Carolina State University
Why do we feed byproducts to cattle and how do we know it is safe? An answer to a consumer
asking about the safety of conventional beef as compared to grass-fed beef.
Matt Poore
These are interesting times in the cattle business. The cost of inputs are high, cattle prices are not as
high as they were a few years ago, and producers are struggling to make ends meet. One of the
bright spots for producers in the Carolinas is the availability of many byproduct feeds that fit well
into our production systems. We use a wide variety of byproducts, some of them common and some
unusual.
Occasionally we get questions from consumers who have been told about some of the more unusual
byproducts we use. Last week such a question came in from someone who had encountered a beef
producer who was selling finished beef at the farmer’s market in her community. This producer had
a jar with a variety of items in it including cement dust, bubble gum, chicken feathers, and some
other unidentifiable items. She was told that this is what we normally feed beef cattle, so she should
purchase grass-fed beef instead of what she could purchase in the grocery store.
Her questions were: Is it true that we feed these kinds of things to cattle, does it affect the quality of
the beef, and how are such feeding practices regulated?
It is difficult to respond to such a question because this is a rather complex subject, and many
consumers find feeding byproducts distasteful, especially with some of the more obscure byproducts.
Given that we all need to be better educated about production practices used in the industry I
thought that it would be helpful for me to print the letter I sent this consumer in response to her
questions.
Dear Ms Consumer:
I appreciate your inquiry about feeding standards used in the beef industry. I am the Beef Cattle
Extension Coordinator at N.C. State University, and a Professor in the Department of Animal
Science. I am a nutritionist with a PhD in Nutritional Sciences including training in both beef cattle
and human nutrition.
For the last 18 years I have worked in North Carolina with a wide variety of beef producers and beef
production systems. I appreciate your questions and am always happy to respond to concerns of
interested consumers. I am very involved in alternative sustainable beef production systems through
our Center for Environmental Farming Systems (search CEFS on Google) and am especially
interested in alternative local beef finishing systems.
To start, it is important for me to give you a little background on the “conventional beef industry.”
Our industry is generally segmented into cow/calf farms, stocker or growing cattle farms, and
finishing in feedlots. North Carolina (and the southeast in general) has primarily cow/calf farms with
some stocker cattle growing farms. Most cattle finishing occurs in feedlots in the high plains (Texas,
Nebraska, and Kansas) and Midwest (Iowa, Illinois, Indiana, Ohio, and Pennsylvania). We have
very little finishing in North Carolina but we do have a growing interest in local finishing and
marketing of beef. This has been stimulated by many consumers’ interest in knowing where their
food comes from and their desire to purchase as much of their food from local producers as possible.
North Carolina is one of the leading states in the local food movement with much of the statewide
activity being led by the CEFS program.
Cow/calf farms generally use forage-based systems which focus on pasture utilization during the
grazing season and hay feeding during the winter. The cows are sometimes fed small amounts of
concentrate (grain) supplements to balance their diets. Most stocker cattle (growing) farms purchase
calves from cow/calf producers and feed them in pastures on forages supplemented with mixtures of
concentrate feeds to prepare them for movement to the feedlots in the High-Plains and Midwest.
Once in the feedlots, cattle are fed on high grain diets (generally based on corn) which also contain
some ground hay or other fiber source and a protein supplement. There has been increased use of
byproduct feeds in all segments of the industry, although finishing cattle are still fed predominantly
grain-based diets.
I have extensive experience working with the incorporation of byproduct feeds into diets used on our
stocker cattle (growing) farms. Cattle have a special role in the use of these feeds because many of
the feeds can’t be used for other livestock species (due to physiological or economical factors), and
if the byproducts were not fed to cattle they would have to be disposed of in landfills or be applied to
land as a fertilizer source. Most byproducts are the result of agricultural commodity (such as grain
and oilseed) processing. Most of these processes purify or extract the portions of grains and other
commodities that are useful for feeding to other livestock species or for use as human food, and the
residuals that are usually high in fiber are of most value in the diets of cattle. In this way, cattle
provide a service of converting these materials that would otherwise be wasted into a wholesome
human food product.
In North Carolina we have a great deal of agricultural processing resulting in byproducts that we use
in calf growing programs. These include soybean seed coats (known as soyhulls, a byproduct of
vegetable oil and soy protein production), corn gluten feed (byproduct of corn starch and corn syrup
production), distiller’s grains (byproduct of ethanol production) and brewer’s grains (byproduct of
beer production). All of these products are most efficiently used by cattle because of the unique
digestive tracts that cattle have.
We also use a wide variety of unusual byproducts that result specifically from human food
production. These include out of date and/or crumbled/broken human food such as flour, crackers,
bread, cookies, breakfast cereal, and processing byproducts including fruit trimmings, sweetpotato
skinning residue, etc. It is sometimes a challenge to fit these materials into balanced diets, but I have
made a successful career of working with producers to efficiently use these resources. These
materials have traditionally been disposed of in landfills, and our efforts have relieved landfill
burdens. The manure nutrients resulting from the digestion of these materials are collected and used
as an organic fertilizer source, or are recycled in the pasture system where they stimulate the growth
of grass that is in turn consumed by the cattle.
Now, after that background I will address your specific questions about the materials that you saw
displayed at the farmer’s market. The truth is that some of these materials might indeed be fed to
cattle in rare instances as part of a byproduct feeding program. However, it is important for you to
understand that the U.S. Food and Drug Administration (FDA), the Food and Drug Protection
Division in the NC Department of Agriculture and Consumer Services, the NC Cattlemen’s
Association, the National Cattlemen’s Beef Association, and nutritionists like me work closely with
the food and agricultural industries to make sure that any use of unusual byproduct feeds is within
acceptable guidelines and will not compromise the safety of the beef available to consumers.
Proposed feed ingredients go through rigorous research and scrutiny before they are approved as
recognized feed ingredients.
In poultry producing regions, brood cows are sometimes fed a byproduct we call “Recycled Poultry
Bedding” which is made by heat treating bedding cleaned out of poultry houses. This in general is a
low energy feed that is used primarily for winter feeding on cow/calf farms. In the past it was used
at a higher level than it is today, and the use has been reduced because of demand for this material as
an organic fertilizer for pasture and crops (including organic vegetables after thorough composting).
This “RPB” is one of the most researched byproduct feeds of all time, and my colleagues and I at
NCSU and at other universities across the south have done extensive research to ensure that it is safe
as a feed and does not have an influence on beef quality. Because this material is used primarily for
mature cows (and generally not in growing or finishing systems) its use is not a concern for the
finished beef you find in the grocery store. From time to time this feed is brought into question
because the thought of feeding it is indeed distasteful to many, but no problems have ever been
identified with the material despite widespread detailed research.
Cattle are also sometimes fed a feed ingredient produced from poultry feathers called “hydrolyzed
feather meal”. Feathers are very high in protein nearly completely indigestible to any animal
including cattle. However, when they are cooked under pressure some of the cross-links in the
protein structure are broken increasing the digestibility of the protein, and making the material a
viable feed ingredient for beef cattle rations. When it is fed, it is incorporated into rations at a low
level to help provide needed protein. Again, this material is something that has potential value, but it
would be completely wasted and disposed of in landfills if it was not fed to cattle.
In regard to the feeding of bubble gum, I have had no direct experience with feeding it, nor do I
know of any producer who has ever fed it. However, I don’t doubt that at times it might be fed in
small amounts to growing cattle in areas near where bubble gum is produced. I have had experience
advising producers who have fed a variety of candy products including gum drops, gummy bears,
starlight mints, chocolate, etc. These all contain some nutritional value from the sugar they contain,
but they are fed at a very low level of the diet. I actually have little concern about the feeding of
candy and other human food products because they have been produced specifically for human
consumption under strict guidelines. Again, these products would not generally be fed to finishing
cattle, and keeping them from landfills is a benefit to society.
Concerning the use of cement in feed, this is simply untrue. I don’t know of any cattle production
system that uses it. When I was a graduate student I was researching factors that influence the
digestive process in cattle. I did find several papers during my research where cement kiln dust had
been evaluated as a feed additive. The idea was that the material when added to a diet at a very low
level would influence the fluid flow through the digestive system. Indeed it was shown to improve
growth and efficiency in some cases, but because of difficulty in handling, unpredictable results,
limited availability and lack of quality control, it was never approved or adopted as a feed additive.
We do use mineral compounds as supplements in all cattle production systems including calcium
carbonate (derived from limestone), but we use this as a beneficial calcium supplement to help the
animals to develop normal bone strength (the same way it is used in human mineral supplements; if
you look at the ingredient label for a human calcium supplement, you will most likely see calcium
carbonate, which is derived from limestone, as the first ingredient).
I apologize for the length of this letter, but you have raised a complex issue and I felt you deserved a
good explanation of why and how byproducts are fed. I commend you on your interest in how your
food is produced. As you are aware, there is great interest in local foods, and farmers markets are
springing up all around the country. As part of this movement, we have great interest in locally
produced and marketed beef. I work with producers who use a variety of production systems, some
are “100% grass-fed” and others use a limited amount of concentrate (grains or high energy
byproduct feeds) in their systems. All of these producers maintain their cattle on pasture (rather than
in feedlots) and are responsive to consumer demands since you can look them in the eye and ask
them directly about how they produce their products.
Grass-fed beef does have some measurable characteristics that make it different from conventional
grocery store beef, but in many cases it is not very different from local beef produced in systems
where farmers use some byproduct-based concentrate feeds. Actually, it generally takes longer to
grow animals to the desirable size in a grass-fed system and some people believe it is better for the
environment and the quality of the beef to feed some concentrate.
I work with a wide variety of beef cattle producers including those who are working with local
finishing, and cow/calf producers who raise calves for the conventional feedlot industry. All these
farmers are good people who are doing their best to make a living and to produce a wholesome food
product for a growing population. It saddens me when I hear of a producer who stretches the truth to
sell products while hurting a neighbor’s ability to make a living.
I encourage you to keep asking questions and to learn as much as you can about where your food
comes from and how it is produced. I also encourage you to support local production as much as
possible. You can feel comfortable eating beef either from the grocery store or from a local producer
as long as you handle it properly after you purchase it, and make it part of a balanced diet. As you
make your purchasing decisions I hope you will keep in mind that we have a very complex food
system that is one of the safest and most efficient in the world. Because of current issues we are
likely to see changes in our food system. It is my hope that these changes can be made without
additional loss of farmers and farmland.
Sincerely,
Dr. Matt Poore
Extension Beef Specialist
North Carolina Cooperative Extension
North Carolina State University