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One type of antibiotic that is used commonly in beef farming (and in other cattle farming, too) are ionophores. These medications act directly on the rumen microbes. They change the way the ions (like sodium and chloride) can pass across the cell walls of the microbes, limit the microbes’ growth and reproduction (they are considered coccidiostats), and change the way they use nutrients.

Ionophores are not approved for use in people, and can be very dangerous to animals that are not ruminants. (For example, ionophores can be deadly to horses if they are accidentally given cattle feed that has this medication added.)

Ionophores are used as feed additives on many beef farms. They are helpful in a few different ways. First, they decrease the incidence of disease caused by coccidia. While all cattle (and all ruminants) have “good” microbes in their rumen, there are also “bad” microbes that can cause disease. These “bad” microbes can cause very severe diarrhea that can quickly result in death. By using ionophores as a feed additive, farmers are using these medications as prophylaxis to prevent diarrhea from coccidial diseases.

In addition to keeping the bad coccidia at bay, ionophores also help to keep some of the bad bacteria under control. Ionophores are more specifically active against some types of gram-positive bacteria. These bacteria can cause intestinal disease like bloat in cattle, so prophylactic use of ionophores in feed helps keep populations of these bacteria low and decreases the incidence of some intestinal diseases.

Another way ionophores are helpful is in increasing feed efficiency of cattle. By altering the way the “good” microbes use ions, these medications also alter the way the microbes use nutrients. Remember that the rumen microbes digest the fiber and protein in the cattle’s feed, and then the cattle digest the microbes as their protein source. Ionophores make the rumen microbes less efficient at digesting protein, so there is more available for the cattle to digest. So now the cattle get a double-dose of protein – some of the protein from their feed, and all of the protein from the microbes.

Ionophores don’t completely stop the rumen microbes from digesting protein, but they do change the end products of protein digestion. The same end products are made (different types of fatty acids), but in slightly different ratios. The cattle can’t use all the fatty acids the microbes make in the same way, and ionophores change the ratio in favor of the types of fatty acids that cattle can use for nutrition more efficiently.

And, believe it or not, all these benefits can be accomplished with a very small amount of medication. These medications are mixed with the cattle’s main grain feed at a ratio of 5-40 grams of medication per ton of feed. That’s 0.011-0.088 pounds of medication in 2000 pounds of feed. That’s a big benefit from a very tiny amount of medication!

All the benefits cattle see from the use of ionophores in feed result in healthier cattle that grow better with the same amount of feed. This results in a cost-savings for the farmer (in veterinary care for the animals and in feed costs), and these savings help keep the cost of meat down at the grocery store.

When most people think of antibiotics, they think about pills or capsules. In small animal veterinary medicine, we do often use antibiotics in the form of pills, capsules, or chewable tablets.

But in cattle things are a little different. Remember those rumen protozoa? Well, they do some funny things to antibiotics, and we can’t use these drugs (or most drugs, for that matter) in an oral form in cattle. So they have to get injections.

Sometimes we use antibiotics that are also approved for use in people, like Baytril. More often, we use antibiotics that are not approved for use in people, like Micotil and Resflor. In fact, if Micotil is accidentally given to a person it can kill them by causing a heart attack and Resflor may have side effects of bone marrow suppression in people.

Because some antibiotics that are approved for use in animals may have side effects in people, it is essential that farmers keep good records of which animals they use antibiotics in, what date the antibiotic was given, and how much antibiotic was given. The farmers then need to be aware of the withdrawal date and not sell the animal for food before that date. At the processing facility, meat can be randomly tested for antibiotic residue, or the inspecting veterinarian can request testing on the meat from an animal they have reason to think might have antibiotic residue.

If meat from an animal is found to have antibiotic residue, all the meat from that animal is condemned (discarded). The farmer who owned that animal will be subject to citations from the FDA, and may see other consequences such as jail time and not being able to sell any animals for food for people. (This can be devastating for a farmer’s business.)

So why do we use antibiotics in beef cattle in the first place? First and foremost, we use antibiotics to treat disease. Just like people, cattle can get bacterial infections that require antibiotics to treat them.

Antibiotics are also commonly used for prophylaxis, or prevention of disease. In many feedlots, cattle are brought in from many different farms in different areas of the country. Some of these cattle have been shipped in a trailer for many hours. The stress of travel and meeting lots of new cattle all at once can lower their resistance to disease and make them more susceptible to infections, especially pneumonia. When new calves enter a feedlot, most farmers will vaccinate them for the most common respiratory diseases. The problem is that vaccines take up to two weeks to be effective. And in the meantime, the cattle may be exposed to many different bacteria.

Often, when the calves get their vaccines when they arrive at the feedlot, they also get a single dose of a long-acting antibiotic. Remember the hormone implants that release hormone into the animal’s body over a period of time? Long-acting antibiotics are similar, except the antibiotics are in a liquid form and are only released for 2-14 days (depending on the medication). This single dose of antibiotic helps keep many cattle from getting sick, and needing even more medications.

Some antibiotics can also be used as feed additives. I know, I just said that we can’t use antibiotics orally in cattle because of their rumen protozoa. The medications we can use orally actuallyhave a primary effect on those protozoa, and a secondary effect on the cattle. We’ll talk about them next time.

The word “antibiotic” is commonly used to describe medications that kill bacteria, fungi, or protozoa. Technically, this is incorrect. “Antimicrobials” are drugs that kill bacteria, fungi, protozoa, or viruses. Antibiotics only kill bacteria. (Antifungals kill fungi; antiprotozoals kill protozoa; antivirals kill viruses.) Doctors and veterinarians frequently use “antibiotics” and “antimicrobials” interchangeably. For the purposes of this article, I’m mostly going to use the word antibiotic to talk about all these kinds of medications.

So now that the definitions are as clear as mud, I’m going to give you a few more. There are two ways that antibiotics can work. They can directly kill the bacteria that cause disease (these are bacteriocidal), or they can just stop the bacteria from growing and reproducing without actually killing them (these are bacteriostatic). Needless to say, if the bacteria can’t grow and reproduce they will eventually die, but curing an infection with a bacteriostatic medication can take longer than using a bacteriocidal medication.

Antibiotics can be produced by one microorganism as protection against another microorganism (like penicillin produced by a fungus that kills bacteria). They can also start as a natural substance, but be modified to have slightly different properties (like Keflex, which started from a fungus but was modified in a laboratory to be the functional medication we use today).

Antibiotics are commonly used in human and veterinary medicine to treat a variety of diseases. As you know, there are lots of diseases that are caused by bacteria (and fungi, protozoa, and viruses). Some antibiotics can be used in both people and animals; some are only used in animals and some are only used in people.

The Federal Drug Administration has stringent testing requirements for any antibiotic that is approved for use in people and animals. When testing a new drug for use in people, the safety and efficacy of the drug must be proven in people.

When testing a new drug for use in food animals (like cattle, poultry, or pigs), the drug must be tested for safety and efficacy in the particular animal species and it must be tested for safety in people. In addition, a withdrawal time must be established for each drug. This is the length of time between the date when the medication was last administered and the date that animal can be sold for food. These dates are based on the half-life of the medication (how long it takes to be eliminated from the body). Farmers must keep accurate records of which animals they administer medications to, and what dose of medication they give. If a company wants to gain approval for one drug in more than one animal species, they must undergo all the same testing in each species.

The Iowa Beef Center has a great article about how hormones are used in beef farming. This article also includes information on the amounts of hormones in some common foods.

In 1.1 pounds of beef from cattle that have not been treated with hormones, there are 5 nanograms of estrogen. (There are 500 grams in 1.1 pounds. There are one billion nanograms in 1 gram. So we’re talking about a very small amount of hormone here.)

Photo courtesy of http://www.freedigitalphotos.net

In 1.1 pounds of beef from cattle that have been treated with hormones, there are 7 nanograms of estrogen. So while the difference between 5 and 7 may sound like a lot, remember we’re talking in billionths of grams. Teeny tiny.

The recommended serving size of beef is 3 ounces. There is 0.9 nanograms of estrogen in 3 ounces of beef from an animal that did not have a hormone implant; there are 1.3 nanograms of estrogen in 3 ounces of beef from an animal that did have a hormone implant.

What about some other foods? You might be surprised…

Photo courtesy of http://www.freedigitalphotos.net

In the same amount of eggs (1.1 pounds) there are 555 nanograms of estrogen. (Granted, you’re probably not going to eat a full pound of eggs in one sitting, but you shouldn’t be eating a full pound of beef in one sitting either.)

Photo courtesy of http://www.freedigitalphotos.com

1.1 pounds of white bread has 300,000 nanograms of estrogen.

And 1.1 pounds of tofu has 113,500,000 nanograms of estrogen.

People have lots of estrogen, too. An adult male will produce 136,000 nanograms of estrogen every day. A non-pregnant adult female will produce around 513,000 nanograms of estrogen a day. And a pregnant woman will produce 19,600,000 nanograms of estrogen a day.

(Depending on the source, the exact numbers for hormone amounts differ a little across publications and websites, but they are similar across the board.)

As a final note, all the hormone implants used in farming do undergo rigorous testing to be sure they are safe both for the animals and people. All products must be approved by the FDA before they are used.

I am sure I haven’t answered every question you might have about hormone use in beef animals. Help me understand what your concerns are, and ask your questions in the comments.

Hormones are used pretty widely in beef and dairy farming. In beef they are used to help animals grow faster. In dairy they are used to help the cows make more milk. We’ll talk about how hormones are used in beef today, and we’ll get into the dairy part later on.

Remember last time that we talked about the hormones estrogen, progesterone,  and testosterone? These are the types of hormones that are used in beef farming. The hormones can be either natural hormones (estradiol, testosterone, or progesterone), synthetic hormones (man-made, but exactly like the naturally-occurring hormone; trenbolone acetate or melengestrol acetate), or plant hormones (zeranol). Different brands will have different amounts and types of hormones. Regardless of the source, the hormones have the same structure and are seen as the same thing by the body.

The hormones are administered to the animal as an implant. They come in a slow-release pellet and the pellet is placed under the skin on the back of the ear. (Have you heard of implants for women for birth control? This is the same concept.) Depending on the brand, they will release hormone for 90-200 days.

This is a cartridge with hormone implants. This particular type will release hormone for 90 days. The longer lasting implants are a little bigger than these. One animal gets one implant.

This is the device that we use to implant the hormones. The cattle need to be in a head gate for restraint when the farmer or veterinarian is implanting the hormones. You can see where the cartridge fits in the “gun.” The needle is placed under the skin where you want the implant to be, and when you pull the trigger a small piston pushes one implant through the needle. It is a very quick procedure.

The reason farmers use hormones is to help the cattle grow faster. Remember, all cattle have these hormones already, we’re just giving them a “boost.” The animals on a feedlot are young steers or heifers, and they have less naturally-occurring hormone than a bull or an older heifer would. The small amount of hormone in the implant, even though it is not enough to increase the hormone levels in their bodies to what a bull or an older heifer would have, helps them to grow as fast as a bull or an older heifer would.

The biggest benefit of the hormones is that the animals can grow faster while eating around the same amount of food as they normally would. They help the animal’s metabolism so they can use the nutrients in their food more effectively to grow and put on muscle. It also helps them to put on more lean muscle mass instead of more fat. This means we can get more lean meat and lean steak from each animal.

On the other hand, because the hormones make the meat leaner, it means the animals still need to be fed a little extra to get the fat marbling in the meat. Meat is graded by its marbling, so this is very important in beef farming. As it turns out, the farmer can still save money in feed costs by using a hormone implant in his animals. And this cost-savings is passed on to you at the grocery store.

Hormones are basically messengers. They are little proteins that are made by one part of the body, they travel through the blood to another part of the body, and then they tell that part of the body what to do.

For example… Insulin is a hormone. It is made by the pancreas, travels through the blood to all the other tissues and cells in your body, and tells your cells when to take glucose out of your blood and into the cells. The cells then use glucose for energy.

Image from http://www.vivo.colostate.edu

Another hormone is thyroid hormone. (This one is near and dear to me.) Thyroid hormone is made by your thyroid gland, travels all over your body, and does things like tell you how much energy you have, tell your heart how fast to beat, and tells your stomach and intestines how fast to move and how much nutrients to absorb from your food.

Image from http://www.vivo.colostate.edu

Some of the hormones you might be more familiar with are estrogen, progesterone, and testosterone. These are reproductive hormones. Among other things, they tell women’s (and female animal’s) ovaries when to cycle, when to ovulate, and determine whether or not a female can get pregnant at a specific time of the month. They also have effects on male reproduction, and on secondary sex characteristics in people and animals. (Remember back to high school biology, hearing about secondary sex characteristics? These are things like body hair, voice changes, breast development, and fun things that happen during puberty. Animals go through puberty, too, it’s just not quite as visible as it is in people.)

All living things – people, plants, animals, and insects – have hormones. You can’t live without them.

So what’s the big deal in food? Many people are concerned about hormones in their food. Yes, it is true that many farmers are using hormones to help their cattle grow faster or their cows make more milk. And people are worried about how this will affect their own health. Absolutely valid concerns. And too much to tackle in this post today. Stay tuned, we’ll be talking more about this in the days to come.

What are your specific questions and concerns? I’ll do my best to address the issues you are worried about as we keep going on this topic.

The goal at a feedlot is to, well, feed the calves a lot. We want to get the calves to grow to around 1000 pounds to be ready to sell for beef. (Then they are called “finished” cattle.) On a grain-fed farm, this will usually be around the time the cattle are 18 months old.

This steer is just about finished. I took this photo about 6 weeks ago, and he has probably been sold already.

On a grain-fed feedlot, the cattle are mainly fed grain. On this farm, they are fed creep feed, which is a mixture of corn with vitamins and minerals added. Most feedlots will feed about the same type of thing. This self feeder lets the cattle eat just about as much as they want. The farmer fills the self feeder from the top (the big bin that is labeled “creep/self feeder”), and the feed spills out the bottom into the tray. The cattle have an all-you-can-eat buffet all day long. This one is on wheels so it can easily be moved to a different location in the lot, or to a different lot.

You’ll notice that these cattle are not on pasture like the cattle on the cow-calf farm we looked at last time. These cattle are on a dry lot. Although during spring in Indiana, it is usually more like a mud lot. This farm has different pens for different ages and weights of animals. You can see a couple of cattle in the background – these are younger and smaller than the cattle in the front of the photo. They are separated so each animal can get the right amount of feed for its growth. If you put a small steer in the same pen with a big steer, the big kid will bully the little kid, and he won’t get enough to eat. So we keep them in groups of their own size (sort of like grade school).

They do get fed some hay (you can see the end of a hay bale in the bale ring – this one has a green ring around the top towards the back of the photo), but they are not on pasture. Remember, the goal of this kind of farm is to get the cattle to reach their finished weight as fast as is reasonable. Feeding too much roughage (hay or grass) will lengthen the amount of time that it takes the cattle to get to their finished weight. The cattle (and the rumen microbes) can use the energy in the creep feed to grow and gain weight more efficiently (and faster) if that is the main part of their diet, instead of roughage like we use on cow-calf farms.

The cattle on this farm do have more space than I was able to show here without getting into the pens with the cattle or heading out into the mud. While they are more confined than the cows on the cow-calf farm, they still do have plenty of space, food and water, and shelter.

I’ve already shown you some of the pastures at the farm that is at our house. Here is the view of the front of our house. (All adult cows here, the calves were weaned and in a different pasture.) All the cows at this farm are registered Angus.

This is part of our other pasture, about 20 minutes away from our house. This pasture is bigger, so we can have more cattle on this part of the farm. We keep our cross-bred beef cows here. (They’re the mutts of the beef cattle world. We still love them, they just don’t come with papers.)

You can see that part of this pasture is muddy (in the front of the photo). Part of that is spring in Indiana, it’s just always muddy here. The feed trough is in this part of the pasture, so this part of the pasture gets a lot of traffic every day. The movement of the heavy cows walking across this ground keeps it soft and muddy most of the year.

There is a lot of grass (and dry ground) at this pasture, but we still need to supplement the cows with hay in the fall, winter, and early spring. We do move the hay bales periodically to keep the ground from getting too torn up and muddy.

These cows also get fed corn every day at this time of year. We have a concrete feed trough at this farm, and the cows line up to get their meals. They’re pretty messy eaters – they drop a lot of food out of their mouths, and they’re kind of slobbery. But they share nicely (for the most part) and do a good job of licking the feed trough clean.

On our cow-calf farm, the main food for the ladies is grass and hay, with some corn supplement when they need it (late pregnancy and during lactation). Next time, we’ll talk about beef feedlots and how the feeding is a little different there. Is this what you expected? What is different?

It’s not slime. It’s beef. There are two different terms for it, boneless lean beef trimmings or finely textured beef. Both products start and end the same, but have one slightly different middle step. Here’s how we get it.

You know how you’ll get a steak from the grocery store, and it often will have a thin layer of fat around the outside. You “trim” the fat from the steak before you cook it, but usually you take a little bit of the meat off, too. You don’t usually spend a whole bunch of time getting that last little bit of meat separated from the fat, you just throw it away. This also happens at the butcher, but on a bigger scale.

Imagine taking all the trimmings from a whole cow (we’re talking around 500-800 pounds of meat, before trimming) and just throwing away all the good meat that is stuck to the fat that was trimmed off.

That’s a lot of waste.

This is edible meat, that just happens to be closely attached to fat or connective tissue. And it is hard to separate. It is not contaminated with bacteria, it is not designated for pet food, it is just stuck to some parts of the animal that we would rather not eat. (Think of that last bit of meat stuck to a T-bone… you probably want to chew it off instead of throwing it away, right?)

Instead of throwing the meat away, there is a way to save the meat, while getting rid of the fat. The trimmings are put into a very big centrifuge, which is sort of like a giant, high-speed mixing bowl. The centrifuge spins around super-fast, and separates the fat from the lean meat. We keep the meat, but not the fat.

Here is where the difference is between boneless lean beef trimmings and finely textured beef.

To get boneless lean beef trimmings, the lean meat is treated with a small amount of ammonium hydroxide gas. This gas changes the pH of the meat, which kills any bacteria that are present. Ammonium hydroxide IS NOT household ammonia that is used for cleaning. Ammonium hydroxide is a naturally-occurring substance that everyone (and every animal) already has in their bodies. It is commonly used as a food preservative, because in small amounts (like used to make boneless lean beef trimmings) it is not harmful to people, but does a great job of killing bacteria.

To get finely textured beef, the lean meat is treated with a little bit of citric acid, which also changes the pH and kills bacteria. Citric acid is similar to the acid in citrus fruits. Again, a naturally-occurring substance, and very safe in the small amounts used here.

Both ammonium hydroxide and citric acid are regulated by the FDA, and are safe products used in food processing.

At the end of this process, both boneless lean beef trimmings and finely textured beef are ground beef that is more than 90% (and close to 100%) lean.

Have you ever cooked with 94% lean ground beef from the grocery store? There is very little fat to drain when you brown a pound up in a skillet, and it falls apart into fine crumbles. But it doesn’t stay together well to make hamburgers or meat balls. And it does taste a little different from 80% or 85% lean ground meat.

Boneless lean beef trimmings and finely textured beef are mixed with ground beef that has a higher fat content (say, 70% lean or less) to bring it up to a lower fat content (say, 80% lean or more). The fat in the ground beef gives it more flavor, and helps the meat to stick together to make patties, or meat balls, or meat loaf, or whatever shape you want. The leanness of the ground beef makes it a little healthier for us.

Boneless lean beef trimmings and finely textured beef are both inspected by the USDA, and must pass safety testing just like any other meat product. If any ground beef (whether it includes boneless lean beef trimmings or finely textured beef or not) is found to have bacterial contamination, it is destroyed immediately and not sent to retailers. If it is found after some has already been sent to retailers, the entire batch is recalled immediately.

Here is a Meat MythCrushers video that talks about the use of ammonium hydroxide in boneless lean beef trimmings.

http://www.meatmythcrushers.com/myths/myth-ordinary-household-ammonia-is-used-to-make-some-hamburgers.html

And this document from the American Meat Institute may help to answer some more questions.

It’s a complicated topic, and there are a lot of questions running around about this right now. What other questions do you have that I haven’t answered yet?