Home Dairy Does Milk come from Pregnant Cows?

Does Milk come from Pregnant Cows?


There is a myth online that says milk only comes from pregnant cows and so should be loaded with female hormones. Not only is this ridiculous logic, but being a dairy farmer I can answer this question

Looking at the farm records

So does milk come from pregnant cows? I am a dairy farmer and have the data from our farm so decided to take a crack at this urban legend. On farms these days, we record all the cow’s health records on a computer database. I’m not always out wielding my pitchfork, but more often than not troubleshooting technology…

I used our database to analyze the percentage of our herd’s status of pregnant/ not pregnant. I also broke down the data of the cows that were pregnant by trimesters.

What most people unfamiliar with dairy farming don’t understand is that the further into a pregnancy a cow goes the less milk she will produce. A cow will give the highest volume of milk when she is open.

The cows that could have the highest amount of hormones in their milk would be in their last trimester. The common practice on farms is to dry up the cow (since she is giving little milk by that time) and give her a vacation for the last two months of her pregnancy. So cows are only milked 7 months of their pregnancy- until day 217 of her pregnancy out of 280 days.

Cows Hormone level over pregnancy

A cow’s blood estrogen levels during pregnancy doesn’t significantly increase until the 3rd trimester when she is dry

I broke the data down by trimester because a cow’s hormone level goes up slowly over the pregnancy. Her hormones are highest in the last trimester- but cows are usually dry at that time.

The data showed that about 89% of the milk came from cows that were not pregnant or in their first trimester. Only 9% of the milk came from cows in their 2nd trimester and only 2% of the milk came from cows in their 3rd trimester because they are only milked for 1 more month in that trimester before they are dried and sent on vacation. The cows in the later periods of their pregnancy gave less milk and are the smallest portion of the total milking herd.

About 90% of the milk comes from cows that are not pregnant or in an early pregnancy. The remaining amount does not contribute to a significant increase in hormones in milk. Milk has been tested to show the average amount of estrogen.


Here is the picture- If you have 14,000 gallons of milk (2 truckloads), here is how it’s divided by Cows in each category. (the % is the % of the milk in the 14,000 gallons)

Does milk come from pregnant cows

The volume of milk produced by cows in the respective category on our farm. About 90% is from cows not pregnant or in early pregnancy.

Milk doesn't come from pregnant cows


Maybe this is a better visual- It is easy to see why milk wouldn’t have a lot of estrogen in it.

The other thing to consider is that just because a cows blood estrogen goes up during pregnancy, doesn’t mean that it necessarily correlates to the amount of estrogen in the milk.

The amount of estrogen in milk

There isn’t much estrogen in milk- around 2ng in an 8 oz. glass. And that is the average in a bulk sample (even with those later pregnancy cows).

Estrogen in milk

People get more estrogen from vegetables like cabbage (at 2,000 ng) than they do from meat and dairy products.

Most people on this topic want other people to drink less milk- it’s a gross-out argument.

The hormones that you eat are broken down by your body. You don’t absorb them like a dangerous virus. And your body regulates hormone production, just like it regulates oxygen in your body. Your body isn’t brainless. (sorry a terrible joke).

It does become imbalanced when you eat too much estrogen- like taking steroids. But steroid users know that taking steroids orally is the most ineffective way to take them.

Why are people worried about milk’s 2ng/serving when there is 20,000-50,000ng in a birth control pill. Then you look at how much estrogen is in humans naturally – 130,000ng in Males/ 500,000ng is a Female. 2ng in a cup of milk will not influence your body in a significant way, especially when it has to go through digestion first.

The logic of the milk/ hormone myth

When you stop to think about it rationally and look at facts and the big picture, it’s really hard to believe that some people believe this myth. Yes, milk comes from female cows, but most things in nature have a sex. Fruits, for example, are plant OVERIES.

Vegans on hormones in milk meme

Vegans have problems with Logic

Hormones in milk

We all eat ripened ovaries and I don’t see people making a big deal about hormone levels in these other foods

Cultures that drank milk

If milk contributed to higher estrogen levels in people, then milk-drinking cultures would be the most estrogen laden people in the world…. But they’re not.

Mongols and hormones in milk

From Marco Polo on Netflix – Mongol warriors drinking milk

Check out my previous write up about Hormones and Milk and why the hormone in milk topic is urban folklore.





  1. Cows, like ALL mammals, must be pregnant or have given birth in order to produce milk. So, dairy farmers forcefully make their cows pregnant, by hand, every year, to get them to produce milk.

    Cows, like ALL mammals, produce milk specifically for THEIR young. They do not produce milk for adult humans, but farmers have learnt how to exploit this placid animal to the max, on an industrial scale.

    Cows, like ALL mammals, produce milk loaded with growth hormones and all the things THEIR babies need to develop properly up to weening. Dairy farmers cruelly deprive calves of their mother’s precious milk so they can steel it and sell it for profit.

    Dairy cows are killed off after just four or five years of milking because they are no longer profitable and besides, the farmer can use their offspring to take their place; it is a production line after all. Cows would naturally live for around twenty years in the wild if they were given that freedom. Dairy cows are treated like disposable milk-producing machines.

    The idea of a “cow vacation” is pathetic – if giving the cow a two month break from milking did not benefit the farmer and his precious profits, he would not do it – it’s all about the profits.

    Attacking vegans by ridiculously comparing fruit and veg to sentient beings who feel pain and fear and recognise love and kindness, in an article about hormones in milk, just about sums up the desperation dairy farmers must be feeling right now as their milk market continues to shrink. This silly non-scientific argument simply attempts to legitimise the way animals are routinely abused in factories. It’s a big fat lie and should be exposed and laughed at long and hard accordingly.

    Dairy farmers have a problem with understanding animal compassion.

    • Glad you replied, hoping for some spirited discussion. I will respond by para:
      1. Cows would get pregnant faster in nature by bulls who don’t ask for permission
      2. We are mammals, we drink milk. Cats also drink cows milk.
      3. Milk is not loaded with growth hormones, this post and my other hormones in milk post dispell the myth. What growth hormones specifically? No one really investigates or looks up the real facts. The baby calves also get to drink milk, we don’t take it away from them. Cows have plenty to share.
      4. Some cows can live to 20 but not all can or will. That is like saying people can live to 120 years. Some can but most will not. Most people also forget that quality of life goes down as you get older. Old age can sometimes not be so kind so hard to say that old age is humane and all cows should live to it.
      5. How is a cow vacation pathetic- cows deserve a vacation. It’s more time off from work than you or I get every year. Plus in cow years, it’s longer than 2 months. Cows have a pretty chill lifestyle and you would love to have their life.
      5. Plants have hormones yet no vegan discusses this. Veganism has little logic when you start applying its principals consistently. Why do vegans only care about animals, but forget about fellow humans or plants (just because they dont have faces
      6. Farmers are animal people that’s why they spend their lives taking care of them. Get to know farmers, everything done on the farm helps make the place better for the animals. Everything revolves around that. If you don’t give to them, they don’t give back

    • Badger,
      That last line of yours was the funniest.

      Here: http://www.dairymoos.com/how-much-butter-people-eat/ in our last exchange I posted nine responses helpfully numbered for you addressing things we discussed. In 6 months you haven’t responded to a single one. Of particular relevance is Post # 1 (June 29, 2017) where I addressed your desired goal of ending the keeping of cows by humans for meat and milk. I had asked “What would you do with the ‘vast numbers’ of domestic cattle we have on hand now?”

      Your response was:
      “B: Farmed animals are “purposefully breed” (I did say this!) in their billions, for human exploitation. I’m sure you must have heard of ‘supply and demand’? I can’t believe you are incapable of working this out. Sit and ponder this for a moment and see if a solution comes to you. I’ll give you a clue… if farmers didn’t “purposefully breed” animals….”

      I found your response lacking in specifics so I attempted to figure out what could be the details and end result of your goal to rid the world of domesticated cattle. Anyone else interested in this as well can read the rest at the link above.

      • Sometimes we choose not to engage with people who we find irritating or foolish.
        My stance is straightforward enough Alvin; I object to the unnecessary exploitation of animals because it’s fundamentally cruel and I therefore vote with my feet. You do the opposite by seeking to justify cruel animal exploitation. We clearly have little in common and there is no middle-ground with you. It’s very hard to have a meaningful conversation with someone who lives in denial and uses abusive language towards me simply because I hold different views.
        I’m afraid you lost all credibility, if you ever had any, when you admitted to eating nothing but lamb for 46 days straight! Who even does that? That’s got to be one of the dumbest things I ever heard, congratulations!

        • Badger,

          Twice over the course of six months now I asked you to explain specifically what you’d do with all the cattle currently “in captivity”.

          There’s been no answer from you. The reason for this is because you have no real answer. You just don’t think that far into the reality of it. Veganism makes you feel good – in the moment. And that’s all. Your entire view on the subject of animals and of nutrition is based on irrational emotionalism – not fact, science or reality.

          I’d happily “choose not to engage” with people who are irritating or foolish. But frankly when you show up hassling the people who provide my daily sustenance it makes me frown. So – unless I’m on vacation – I am going to engage you promptly every time you show up.

          You’ve made a number of claims about how you have concern for animals while I supposedly don’t. Your words and views are all over this blog and so are mine. Anyone can read through yours and mine and judge for themselves where each of us stand on the treatment of animals.

          “We clearly have little in common and there is no middle-ground with you.”
          I’m a human. Are you not? As to “middle ground”, can you define what that would be in a discussion where I note that I am continuing to drink milk just like my forebears did for some 7,000+ years while you are saying cows are “being raped”?

          You say humans drinking cow’s milk is “unnatural because no other animals drink the milk of another”. But some animals also eat their own excrement. So I don’t want to think what the “middle-ground” might be that would satisfy you. I’ll just be an uncompromising extremist and stick with milk and you can be “natural” and eat your poop. You’re not still “in denial” about poop-eating are you?

          “It’s very hard to have a meaningful conversation with someone who lives in denial and uses abusive language towards me simply because I hold different views.”

          It is indeed hard to have a meaningful conversation with you but I think I gave up on that a long way back. I only post here to oppose you because you insist on threatening my food supply. I could not care less (or could I?) whether you change your views. I have nothing to gain by you buying milk or eating meat from now on. It just doesn’t matter to me. I’m neither your mother nor your “keeper”. And with the most sincere of intentions (“honest…”) I encourage you to take action upon your own belief that “cholesterol is bad, dangerous, etc” and suggest that you start taking statins to lower whatever you currently have. I mean, you believe you’re right about that too, right?

          I “lost my credibility” because of a brief experiment? Humans have gone much longer than 46 days eating only meat. https://en.wikipedia.org/wiki/Vilhjalmur_Stefansson#Low-carbohydrate_diet_of_meat_and_fish
          How terribly racist and ethnocentric of you to say that going that long on meat alone is “the dumbest thing” you’ve ever heard. That’s blatant intolerance of different views.

          Happy New Year!

  2. Dadgummit. The milk-haters are right on this one… Just look up the Battle of Hastings in 1066 and read about William the Estrogen-Laden.


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