Friday, July 20, 2012

Antibiotics in the meat supply: Residues vs. Resistance

There has been a lot of news coverage and proposed legislation lately calling for the banning of antibiotic use in farm animals. People can get very frightened when we talk about antibiotic resistant bacteria or antibiotics in the meat supply.
 
This has been an especially personal topic for me because our family recently had a scare with antibiotic-resistant bacteria. In May, my daughter had a little lump behind her ear. I found it over a weekend and by Sunday evening, she was running a low fever, so we went to the doctor on Monday morning. By 6pm, we were admitted to the hospital with a very high fever and a freshly-lanced abscess. It took 2 of days of testing, and she was diagnosed with MRSA (methicillin-resistant staphylococcus aureus). She spent three nights in the hospital on IV antibiotics. Now, she’s fine and back to her little rotten self.
MRSA - Antibiotic-resistant Staph
Experiences like ours are very scary, and I know there are a lot of parents with much worse stories to tell than mine. However, most people know very little about antibiotic-resistant bacteria like MRSA. When they hear about antibiotics in relation to our food supply, they don’t know what to think.
 
First, what exactly are we talking about?


Antibiotics administered to animals headed to the food supply.
  
Why are animals given antibiotics?
 
There are three reasons why animals are given antibiotics.
 
1. The most obvious reason is that animals are given antibiotics when they are sick or injured to fight infection.
 
Most people agree that it would be inhumane to withhold a drug from a sick animal and allow it to suffer. Even organic farms and antibiotic-free farms have a protocol in place to treat a sick animal and remove it from their herd.

2. Sometimes animals are given antibiotics to prevent them from getting sick. 
 
Just like kids, young animals are prone to infection. In some farms, animals live very close to one another and they are not very clean creatures (you just can’t teach a piglet to wash his hooves), so if one gets sick, they could all get sick very quickly. That could spell disaster for a farmer, so some farms choose to feed a low level of antibiotics to prevent disease.

 
3. Some antibiotics are given to improve how fast and efficiently animals grow.
 
This is probably the most controversial reason to give animals antibiotics. Animals live in symbiotic relationships with several types of microorganisms. (Cows use microorganisms in their stomachs to digest grains, grass and hay). When antibiotics are given to promote growth, the farmer is trying to maximize the good bacteria in their bodies to help them grow more efficiently. The antibiotics that are used to help animals grow are different from the ones used to treat sick animals and humans.
 
  
You may have heard a statistic in a news story that said that 80% of the antibiotics sold in the US are given to livestock animals. That number is largely disputed. First, it is impossible to know how many antibiotics are sold in the US, for use in livestock or in humans. Second, a large percentage of drugs used by farmers are not useful in human medicine. Lastly, livestock represent a larger population of bodies than do humans. And, cows and pigs are a lot bigger than humans; pound for pound, they need more antibiotics. What is the real number? Who knows?

 
What about antibiotics in my meat?
 
When people in the food industry talk about antibiotics, there are two terms they use: antibiotic residues and antibiotic resistant bacteria.
 
Antibiotic residues’ refers to actual antibiotic chemicals that have been given to the animals, either fed or given as injections, remaining in the edible tissue (meat, fat, or even milk).
 
The Food and Drug Administration regulates the approval and use of antibiotics in animal medicine. Any antibiotic that is given to a food animal has a specified ‘withdrawal time’ which is the amount of time that the antibiotic has to be withdrawn from the animal before it is slaughtered. These times are based on how long it takes the animal to process the antibiotic so that it is eliminated from the body. Farmers must wait to slaughter an animal for that amount of time after giving the antibiotic to the animal or they will be breaking the law.
The Food Safety Inspection Service (part of USDA) monitors the meat supply and tests for antibiotic residues in the meat. The levels of antibiotic residues found in the meat supply are very low (below 1%), and tests are done on a worst-case scenario basis, which means FSIS tests the tissues that are most likely to contain antibiotic residues (liver and kidneys) and they test a larger percentage of suspect animals (old cows, animals with injection scars, etc.). Although the levels are not zero, I am not really worried about antibiotic residues in meat.
 
A group called the US Farmers Ranchers Alliance has a video of experts discussing antibiotic residues.

 
Antibiotic-resistant bacteria’ refers to bacteria that are not easily killed by common antibiotics, they are resistant.
 
How do bacteria become resistant to antibiotics?
 
Bacteria are everywhere, and there are millions of species, strains, and serotypes… all fancy ways of saying ‘different’ bacteria. Bacteria have a genetic code, just like humans, and they change and evolve with each generation. Unlike humans, they multiply at crazy-fast rates, so their genes can change at fast rates. When you introduce something to kill the bacteria like antibiotics, most of them die, but a few live. The ones that live may have had something in their genetic code that allowed them to survive the antibiotic treatment. All the other bacteria are gone, so that leaves more room and food for the left over bacteria to grow. When they grow, they pass their antibiotic-resistant genes to the next generations. Eventually, those antibiotic-resistant bacteria are spread around, and found all over the place. We have to learn to fight them in different ways.
 
A study from 2003-2004 found that MRSA (the bacteria my daughter fought) was in 1.5% of American noses. That was 8 years ago, and the bacteria have been spreading since then, so the numbers are probably larger now.
 
Are antibiotic-resistant bacteria in my food and how did they get there?
 
Yep. Antibiotic –resistant bacteria are in our food supply. They are everywhere.
 
Our food is handled by several different people and goes through several steps to get to our plates, and bacteria can be introduced at any of those steps. Some people want to blame the use of antibiotics in animal feed and that may be part of it, but it is likely that several actions contribute to the spread of antibiotic-resistant bacteria.
 
Can it make me and my family sick?

There are some forms of dangerous food borne pathogens like Salmonella and E.coli that have developed some resistance to antibiotics. That means that if you get one of these bacterial infections in your gut, it will be harder for doctors to help you fight them. But, even the non-resistant forms of these bacteria are very dangerous and can make you very, very sick.
 
What can I do?
 
Antibiotic resistant bacteria are susceptible to foodsafety measures such as cooking food thoroughly and keeping raw food away from cooked food. 
 
  • Cooking kills antibiotic-resistant bacteria just like it kills antibiotic-susceptible bacteria. Use a meat thermometer to be sure you cookmeat thoroughly
  • Hot soap and water wash antibiotic-resistant bacteria off of counter tops and utensils. 
  • Antibiotic-resistant bacteria cannot grow as well in cold environments just like the antibiotic susceptible strains, so getting fresh food and leftovers chilled quickly is very important.
  • Antibiotic-resistant bacteria can’t jump through the air from raw food to cooked food, so keep raw and ready-to-eat foods separate.
  
Anything else?

The main two bacteria species that we hear about when we talk about antibiotic resistance are Staphylococcus aureus (MRSA) and Clostridium difficile. Although they are huge issues in the medical industry, the CDC does not see them as a risk in the meat industry. Food safety practices should keep you from getting sick from these bacteria in your food.

However, you may have heard that MRSA has been found in 6.6% of pork samples in a US study. I emailed the author of that study for this post. She was really nice and said that the worry with MRSA in meat is not as much about getting sick from it being in your food as it is about the MRSA spreading from the raw meat to other surfaces and being introduced to a scratch or an open sore and causing severe skin infections, like the one my daughter had.

Lots of bacteria from raw meat can cause skin infections if they are introduced to an opening in the skin, and these antibiotic-resistant ones are very hard to fight. So, my advice is to be extra careful with raw meat, especially with children (face it, they are dirty little monsters. I’ve seen mine lick the bottom of her shoe.).
 
Keep raw meat separate from other food from the time to pick it out at the grocery store until you cook it.  
 
 
  • Use a plastic bag to keep raw meat away from other food items and away from surfaces like the bottom of the grocery cart.
  • Wash your hands after handling raw meat
  • Wash down the countertop with warm soapy water after it came into contact with raw meat (even in the package)
  • If you have a cut on your hands, wear gloves when handling raw meat (like when you make hamburger patties.)
  • Don’t let very small children handle or be in contact with raw meat
My friend Karen sent me this picture of her grocery cart. Her roast is in its package away from the rest of her food. Looks like she put a piece of butcher paper under it. Way to go Karen!


There have been studies connecting antibiotic-resistant E. coli bacteria from chicken to urinary tract infections. If I have been handling raw meat, I wash my hands before AND after going to the restroom.

I called and asked the pediatrician if there was any way to know where the MRSA that infected my daughter came from, and there was not. The doctor told us that lots of people are infected with it and kids ‘pick their nose, then pick their wounds.’ Gross.

What about buying meat from animals that have not been given antibiotics?

There are companies and farms that offer meat from animals that have never been given antibiotics. I’ve talked about such programs in a previous blog post. If you choose to buy those products because you want to support the practice of never giving animals antibiotics, that’s fine, but you should know that meat from these farms are not guaranteed to be free from antibiotic-resistant bacteria. The meat is not any safer than the meat that does not make that claim. A recent study found that the levels of Staphylococcus aureus and MRSA in pork were the same regardless of it being from pig farms that did not use antibiotics.

Denmark has banned the use of sub-therapeutic antibiotics and the results have not been positive for their pork industry. Jeff Fowle, a rancher and blogger from California discusses the ramifications of Denmark's decision in his blog.

Like I said earlier, there is lots of info on the internet about antibiotics (residues and resistant bacteria) in meat and in general.

I don’t know all the answers. Here is a list of a few more resources if you are interested.

MeatMythCrusher Video with Dr. Keith Belk

National Residue Program Fact Sheet from AMI

AMI Fact Sheet about antibiotics


NCBA facts on antibiotics

CDC page on antibiotic resistance

Antimicrobial resistance learning site for vets

FAQ from AVMA (American Veterinary Medical Association)


46 comments:

  1. Great blog. I think a good solution is to adapt newer tech like irradiation and high pressure processing to some of these packaged meats.

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    1. Thanks! I agree.

      Those technologies would go a long way to help prevent disease and infection. Hopefully, processors will start to implement them and consumers will accpet them. (especially irradiation)

      Thanks for the comment and the twitter follow!
      Janeal

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    2. The last thing I would want is for my food to be irradiated, Are you people crazy?

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    3. You'd be surprised to find that several staple items that you eat currently are irradiated.. As in - lettuce! Yep! That nice green iceberg lettuce has been irradiated, as is most lunch meat. Educate yourself.

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  2. GREAT post! We grow turkey for west liberty foods and I think that their plant in Tremonton, UT uses HPP.

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  3. GREAT post! We grow turkey for west liberty foods and I think that their plant in Tremonton, UT uses HPP.

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    1. Thanks.

      When I was at KState in grad school, the microbiologists there were working on HPP.

      Its cool to see the technology come full-circle.

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  4. It worries me how "technology" is tampering with nature in such ways.

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  5. You are ignorant about animals and their feelings (yes they have feelings, anyone with a dog can tell you that). Advocating for sow stalls is appalling, especially coming from a mother. These creatures are veritably tortured, not even being allowed to turn around. Who's paying you to write your bull?

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    1. That's...kind of off topic of what this post is about. But alright.

      I think this article is great! It answers questions I have had. I have taken virology, biology, microbiology classes so a lot of this is very relavent. Thank you for sharing, JanealY

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    2. Yeah, off topic for sure. I'm sure the animals might "feel" better if the animals are given medicine when they are sick.
      I think that each side of this debate would benefit from the use of new alternative ways to rid the bacteria from the meat we consume.
      Great write-up! EMAW!

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  6. Hello, I'm in beef Glazed, love, can not live without. And you? Know where in the United States some cooperative specialist meat breed Simbrah? Have you tried? If you have any information could warn me. Thank you.My email is comercial@gugabianco.com.br

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    1. I'm not sure that I understand your comment.

      Simbrahs are a breed of cattle, a cross of Simmental and Brahman. I don't know if I've tried them specifically. They should be as safe and tasty as any other US beef.

      Thanks,
      Janeal

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  7. Most of your information is on point except regarding Denmark. Initially things were problematic (but they already were becaause they had so much MRSA)... they found no difference in rate of growth on or off growth promoting antibiotics.

    Also CAFOs and the crowding in them spread disease - instead of loading up on antibiotics we should do the humane thing and not pack animals in so tightly. There are many homeopathic and organic alternatives to keeping our animals healthy and treating them humanely..... the solution is not in accepting the situation and you propose but in changing it to create safer and more humane food production. It is also the moral thing to do.

    Instead of putting the responsibility on the consumer to protect themselves from the raw meat and its packaging (meat in your grocery store has contaminated packaging covered in C. diff and MRSA) Why not make the meat safe to begin with. Children can die from contamination.

    Even better there is no good reason to eat meat to begin with. Going vegan protects you and your family from MRSA and other deadly diseases like certain cancers, heart disease, and diabetes. We would be a healthier country if we abandoned meat all together. And, we would have better animal welfare.

    Most people have never been to a slaughter house and seen the process.... they don't understand where their food truly comes from.

    Signed - your local food veterinarian who believes organic & vegetarian lifestyles are the humane healthy way to live!!!

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    1. Thanks for the comment. I appreciate your input, but I think you are trying to make things too simple.

      Research has shown that removing antibiotics from the live animals does not eliminate antibiotic resistant bacteria from their meat.

      I think consumers should understand 3 basic things when it comes to antibiotics and the meat supply.

      1. Antibiotic residues are not allowed in meat.
      2. Antibiotic resistant bacteria are found everywhere. That includes all types of meat and food stuffs.
      3. All bacteria will die (even the antibiotic resistant strains) and the food will be made safe if you cook it and keep your cooked food separate from raw food.

      We live in a messy, imperfect world. There is no way to completely eliminate bacteria from food. Folks in the industry work hard to prevent pathogens from contaminating the food supply. However, consumers should try to be more well informed about how to keep themselves safe. That's who I am trying to help with my blog.

      If you are interested in the operations of a slaughter house, I wrote a post about that earlier this month. Look for 'What Temple Grandin wants the world to know..."

      Thanks again and take care,
      Janeal

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    2. To respond to the above comment, vegetarianism is not sustainable in dry, arid climates, especially the intermontane west that requires huge water intake from large sprinkler systems that often come from dammed rivers to produce fruits and veggies. Sustainably grown fruits and vegetables must be shipped in from elsewhere. Cattle, when stocked appropriately and on open rangeland, act as a vital dusturbance to keep these grasses healthy. They in essence replace the mostly extinct bison on the landscape and help rather than harm the environment.

      Veganism on the other hand is a nearly impossible diet to stick to unless you eat ONLY FOOD YOU PRODUCE YOURSELF.

      -a wildlife biologist who doesn't work for the meat industry

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  8. Clearly you and your Ph.d have sold out to the industry and their blame it on the consumer not following appropriate food safety techniques, mentality.

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    1. I think she clearly explained that responsibility lies at both ends - the highly regulated meat industry does its part to meet government standards, and the consumer should handle and cook the food in a safe way. From the comment above:

      1. Antibiotic residues are not allowed in meat.

      3. All bacteria will die (even the antibiotic resistant strains) and the food will be made safe if you cook it and keep your cooked food separate from raw food.

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  9. Excellent article. Something people need to understand, there is a difference between farms that "mass produce" and "family farms". Our neighbors moved from California to Central New York (4 hours from that blasted City...lol). They were amazed at the difference in the farming techniques. My nephew raises beef cattle. They are healthy and beautiful to behold. They are not crowded and they are not filthy. Does he give them antibiotics? If they need it and only if. I have seen cows that he has bought at auction, come to the farm, filthy and in really rough shape. After being on the farm for a time, they start filling out and getting cleaner. It is wonderful to behold. By the way, I buy my meat from him.

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    1. I really appreciate your comments. It is amazing how animals will recover when they start getting some groceries.

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  10. Nice blog post. I have a PhD in Microbiology and currently work in the Microbiome field and agree with everything you've written. I also have two kids - one of which recently infected a mosquito bite with bacteria from his own pink-eye infection (Shake My Head - SMH).I think you've done a nice job at explaining things on a level for the general public to understand. That's an art in and of itself.

    I'm sure you're familiar with Martin Blaser's (from NYU) work looking at subclinical doses of antibiotics in cattle (for enhanced growth purposes) and the connections he's made with the coinciding rise in obesity in the U.S. It's more about how the antibiotic usage shapes the microbiome and leads to major shifts in BMI, rather than the spread of antibiotic resistant bacteria. I'd be interested to hear your thoughts on this.

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    1. Thanks for the nice comment. I appreciate the mosquito bite story. We had a similar one with a tick bite and diaper rash (before the MRSA).

      I'm not familiar with Dr. Blaser's work. Microbiome work is really out of my field. I have done a little research and found some papers. I'm going to try to look them over and get back to you.

      Thanks again for the great comment.
      Janeal

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  11. Kris KellermeyerJuly 25, 2013 at 6:15 AM

    I sincerely appreciate the thoroughness with which you tackle these topics, and I love that you cite your sources either in text, or with links. It's hard to ask for a better synopsis than this.

    I am currently involved with a pharmacokinetics study which is designed to provide more specific data on withdraw times of antibiotics (and anti-inflammatories, and dewormers) in various species of swine. The data currently yielded by the USDA was obtained by studies which were not as thorough as one might imagine - and could potentially be inaccurate. However, when you introduce the idea of genetic evolution, modified breeding, and genetic selection, it seems prudent to re-do these studies every decade or two anyway.

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    1. You sure have a good point. I appreciate the comment.

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  12. Very helpful article, thank you.

    What is your response to the attack on growth hormones, particularly w/ chicken? Claiming that girls are developing much sooner, as young as 6 yrs old.

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    1. Thanks for your comment.

      Hormone use is actually not allowed in poultry production in the US, so it's not really an issue.

      I don't have a post about it, but you might want to check out this video of a conversation with Dr. Chris Raines. http://www.meatmythcrushers.com/myths/myth-hormone-use-in-poultry-production.html

      Thanks,
      Janeal

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    2. But they are used heavily in cattle. Both reproductive hormones in beef and dairy cattle and (rBST) growth hormone in dairy cattle. As for antibiotic residue in beef not every cow that goes to slaughter gets checked for residue they are picked randomly from the total, Dairies get caught often so you know that there are some getting through because they don't check every cow.

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  13. Thank you for the great article! It's great to see ag-educated women spreading their knowledge!

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  14. I think your article is great. I get really irritated at all these vegans and vegetarians who want to tell this animal (me) what to do. All the vegans and vegetarians tell me how healthy their life style and choice of foods is, and yet all of the vegans and vegetarians I know have heart problems, high cholesterol and anemia. I don't classify that as healthy. And most of them have never seen a farm. They just spew all the lies their city friends who have hidden agendas have told them. Thank you, I will eat meat, especially from animals which have been taken care of with appropriate antibiotic care. And if they think the free range animals are so happy, take a good look at them--most of them are starving and eating unsanitary scrabble. And they just end up as coyote bait.

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  15. This is a really well written and straight forward essay. The use of antibiotics is so complex, and I am very impressed with your ability to break apart and clarify the different factors.

    Thanks so much for all of your work.

    All the best from Nebraska,
    Anne Burkholder
    Feed Yard Foodie

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    1. Thanks so much for the great comment! I love the Feed Yard Foodie Blog. When I was a little girl, my grandmother worked at a feed yard in Texas.

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  16. Thanks for this easy to understand blog about antibiotic use and resistance. I am a dairy farmer
    and we use antibiotics when our animals need them. We use Best Management Practices to keep our animals healthy. These include but not limited to quality feed, clean pens and stalls, fresh air, clean water, fan and sprinklers when the weather is hot, good milking procedures, clean milking equipment, gentle handling of the animals. We have a vaccination program that protects our animals from the most severe ailments they can get. We are the first link in the humane food chain and quality starts with us.

    Thank You

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    1. Thanks for the great comment. I really appreciate the work that farmers do to help keep our food safe. I don't think that they get enough credit for their link in the food safety chain.

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  17. Quinolone antibiotics stay in the body for a very long time, far longer than any USDA policty of waiting prior to slaughter, and there are many people who have had serious reactions to these antibiotics and cannot consume these animals safely. Also if they remain in the animal in significant enough quantities to cause a reaction in a susceptible human who eats the meat, you can bet they are potentially encouraging bacterial resistance.

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    1. I appreciate your comment. I would be curious to know if there have ever been cases of people consuming meat with antibiotic residues and having allergic reactions. I tried to find some, but I don't have access to my search engines this week and didn't find anything.

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  18. Very nicely written! The article neatly describes the hows and whys of using antibiotics in meat production and for outlining practical health safeguards. I don't wonder if the larger point of developing drug (and multiple drug) resistant strains of bacteria through the use of prophylactic/sub-therapeutic doses of antibiotics was missed however. Many public health experts seem to be focused on this. We all would be well served by managing the unintended consequences.

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  19. Thanks for the well-written article. I raise goats and can tell you that they are cleaner than most people. Safe food handling practices are the most important step in preventing food poisoning...

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    1. We had a few goats growing up. They are funny creatures. Definitely clean.

      I think farmers are underappreciated when it comes to their role in keeping our food supply safe. Thanks!

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  20. Thanks for posting this article. I will be passing it on. As a pork producer who is often asked about the use of antibiotics on our farm, I always reply that yes, we use them, but only when needed. The public needs to remember that antibiotics are expensive and administering them on an individual basis is even more costly. It takes time to chase sick animals down with a syringe! Both the antibiotic and labor increase our production costs thereby reducing our bottom line. It's easier and more cost-efficient to be proactive when it comes to herd health.

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    1. Thanks for the great comment!

      I really love to hear from farmers about what really happens on the farm every day!

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  21. Great blog Janeal, you have given me some good facts that i can use in the future. Thank you

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  22. Another good practice (which most restaurants follow, but homeowners don't always use) is to make sure your raw meat is separate in the refrigerator from your other foods- best if it is as low as possible- so that it can't drip on anything else.

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    1. That's a great point! Thanks for the comment.

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