For the Love of Goats
Today we are talking about two separate problems that a lot of goat owners encounter — milk that tastes “goaty” and does holding back their milk.
First, I’m talking to Katherine Boehle, Ph.D., about how bacteria in milk causes a bad taste — and it doesn’t matter whether that bacteria is alive or dead, harmless or harmful, so pasteurization is not the answer. Dead bacteria tastes as bad as live bacteria.
Then we are talking about one of the greatest frustrations of anyone who has ever milked a goat (or cow or sheep or whatever) — knowing that there is still milk in the udder but being unable to get it to come out. If you’re an experienced milker, you know what I’m talking about. If you haven’t experienced this yet, you will at some point if you are milking a goat that is raising her own kids. I’m talking about research I helped with where the cows were holding back their milk for their calves, as well as a study I read where they learned that kids are able to elicit an oxytocin release from their dams, which causes the milk ejection reflex to occur. If you can’t get that, then you will only be able to get the milk that has been stored in the cistern — not the butterfat-rich hind milk.
Homeschooling with Goats — another episode with Katherine talking about how growing up on a farm turned her into a science nerd.
2:30 Fixing Gross Milk in Kenya
5:00 How Bacteria Affects Taste
13:30 Milking Devons
14:30 Getting Optimal Milk-Fat
For more information about milking goats
Listen right here by clicking on the player above, or on your favorite platform:
For the love of goats! We are talking about everything goat. Whether you’re a goat owner, a breeder, or just a fan of these wonderful creatures, we’ve got you covered. And now, here is Deborah Niemann.
Deborah Niemann 0:19
Hello, everyone, and welcome back to another episode. I am really excited today to be joined once again by my daughter, Catherine Bailey, Ph.D., who is gonna be talking about the science of milking today. Hey, Catherine, welcome back!
Catherine Bailey 0:34
Hello! It’s good to be back. You know, thanks for having me on again. I’m excited to talk about some of the research that I did in grad school.
Deborah Niemann 0:41
Yeah! And we’re gonna talk about some of the cool—also, some of the reading of the research, which I did. I’m so careful now about saying, “I do research” because I’m like, “Well no, most of the time I’m reading research that somebody else did.” Because you have done real research yourself. So, let’s dive right in to something that I know is a big problem for a lot of people who milk goats, and that is that it can taste “goat-y.” And I don’t know if you remember this, because we moved out here when you were nine, and then you started milking about a year later. So, I don’t remember exactly when I figured this out. But when we got started in 2002, I had absolutely zero clue that you were supposed to clean the udder or put a few squirts of milk into a separate container, initially. And, we did not know why we would get sometimes perfectly delicious milk, and sometimes milk that tasted like you were licking a buck. It was just so gross. Like, it would make me gag. If I put it in a cup of coffee, I’d wind up dumping my coffee down the drain. And then I learned, “Oh, you’re supposed to clean the udder,” and cleaning the udder definitely helped a lot. And then I learned about doing first squirts to… Because the tip of that teat has some bacteria in it, because it’s been sitting there for the last 12 hours since the last time you milked. And so, it was really fun, then, when you went to grad school, and then one day told me that you were working on research to try and help dairies in Kenya have milk that didn’t taste gross. So, I thought that was a wonderful coincidence. So, can you tell us a little bit about, like, how your lab got contacted, and basically the research that you did with them on their gross milk?
Catherine Bailey 2:40
Yeah, of course. So, it’s kind of funny, because if you listen to the episode where I talked about my education, my Ph.D. is technically in Bioanalytical Chemistry. It’s not in milk or agriculture or anything. So, it probably seems kind of random. But he was contacted—my boss, my advisor—he was contacted by the Kenyan government, I believe; I don’t know what tier of government. But in case you didn’t know, Kenya is actually one of the top producers of milk in all of Africa. And I believe he said there was, like, hundreds of thousands of farmers in Kenya that produce milk, and it can be any—like cows, goats, camels, and sheep. And what we learned is that, instead of like in the United States, where our farms, you know, come from select farms that have hundreds if not thousands of dairy animals, in Africa, they come from lots of very small farms. The average farm, I believe, had, like, ten animals, whether it was goats or cows. And what would happen is that they would pool all their milk together. And what they found is that sometimes, you know, the farmers would come with very clean milk, and other farmers would come with very dirty milk. And the issue is that, when you pool them all together, then all of your milk is bad. And they wanted us to come up with a point-of-need test that could detect bacteria very quickly. Basically, a farmer would bring in milk, they would add a little bit of milk to a test, and it would turn colors indicating that there was excessive bacteria contamination, because that is basically what it breaks down to—about whether your milk tastes bad or not—is that pretty much comes down to bacteria.
Catherine Bailey 4:20
A lot of my research in general, actually, in graduate school, is not in diagnostics, but actually in food safety. So, you know, there was a couple years ago, there was that massive E. coli outbreak from spinach. And that turned out to be due to fecal contamination. I could point to so many different food illness outbreaks that come down to fecal contamination. And I know we probably didn’t catch on to this early on, but I know, towards the end of before I moved from the farm, if any sort of fecal matter from the goats dropped into the milk bucket, we would just dump that milk, because that is just introducing literally millions of bacteria into your milk. And that probably has a lot to do with it; we’ll probably discuss this a little bit more. Hair has bacteria on it; skin has bacteria on it. And yeah, if you can—and so the idea was that, in Kenya, if they could catch this dirtier milk before they contaminated everything, they’d have to throw out a lot less milk.
Deborah Niemann 5:20
So that is the first step, is to figure out like, “Oh, you’ve got contaminated milk, don’t use it.” And one of the things I want to say too, before people freak out and think, “Oh my gosh, there’s bacteria in my milk”—most of this bacteria is completely harmless. Now, obviously, if it came from feces, then you could be talking E. coli and all kinds of stuff here that could make you sick. But, like, a lot of the bacteria that is on a goat’s skin or their hair or something is just… It is a bacteria that is not going to take up residence and cause illness in a human body. But bacteria apparently does not taste good.
Catherine Bailey 5:58
No, especially when it comes from feces, I can—super quick—I detected a lot of different kinds of bacteria. And I remember I was often given the bacteria blind to detect it. So I would be given bacteria samples—and this is when I was detecting antimicrobial-resistant bacteria. And someone from another lab would give me blinded bacteria samples, and I needed to detect the antimicrobial-resistant bacteria. And these had already… These are bacteria that had been isolated. And one of the bacteria samples, after it grew up to a, you know, high concentration so I could detect it…. Most bacteria to me kind of smells like dog food, honestly. But this bacteria smelled like feces. And I was just like, “Oh no!” I was like, “Why does this bacteria smell horrible?” Turned out, it had been isolated from human colon. So.
Deborah Niemann 6:45
Okay. That would make sense, then.
Catherine Bailey 6:47
Just a quite fun fact there. Yeah.
Deborah Niemann 6:49
Yeah. And then, the second part of that research that you were doing that was so fascinating is that they wanted to figure out if they could separate out the bacteria from the milk. And what I thought was interesting about that—because I remember, I asked you, I’m like, “Well, don’t they pasteurize it?” And you said, “Well, yeah, but dead bacteria tastes bad, too.” And so, if you’re thinking, “Oh, well, why don’t you just pasteurize it?” It’s because you’re not removing the bacteria when you pasteurize it, you’re just killing it. And apparently, dead bacteria doesn’t taste any better than live bacteria.
Catherine Bailey 7:28
Yeah, it’s funny because I remember talking… You know, growing up, I would tell people, it’s like, “Yeah, I grew up on a goat farm.” And they’d be like, “Oh, goat milk tastes horrible. How could you drink that?” And I was like, “What are you talking about?” They’re like, “I tried goat milk once, and it tasted like goat.” I was just like, “Well, clearly you got your milk from someone who didn’t clean their goats very well.” And, you know, those were—and I think they even mentioned this was a store-bought milk. Like, you’d think it wouldn’t taste so bad because it’s pasteurized. But like, pasteurization doesn’t help with the taste.
Deborah Niemann 7:56
Yeah. I know so many people who, before they bought goats, they thought, “Oh, I’m gonna go to the store and buy some goat milk and see if I like it.” And they said that they almost didn’t buy goats because the goat milk at the store tastes so gross. And that luckily, then, they met someone who has goats, and they went to their farm, and they tried their goat milk, and it was delicious. It didn’t taste anything like the stuff they had bought at the store. And then, a vet actually told me that a lot of times people who work in very large dairies don’t clean the udder very well because their assumption is, “Well, the milk is going to be pasteurized. The udder doesn’t really need to be cleaned.” Because they’re just thinking about safety; they don’t realize how it affects the taste.
Catherine Bailey 8:44
Yeah, absolutely. And going back to what you’re saying, you know, I kind of… It wasn’t a main part of the research—the filtering out bacteria. That was actually more of a focus on the fact that our limit of detection wasn’t as low as we wanted it to be for detecting bacteria in milk. And so, that was kind of a question like, “Hey, can we isolate the bacteria from the milk really quickly in order to detect it?” And that’s when I discovered that, apparently, this is kind of like an issue that’s been… I mean, it’s still an issue, that you can’t really separate bacteria from milk using a filter; you can’t use a size-exclusion filter, because I learned that fat globules are the exact same size as bacteria. Which is a bit of an issue. And it’s kind of funny, because I remember I was looking at research, and most of the research about separating bacteria from milk are actually from the 80s and 90s. Like, it’s not something that people have been trying to tackle recently. But, the best that they have so far is that—you know, I found, like, a couple patents on it—but there’s a way of separating bacteria from milk where you do a centrifugation process. So the fat, I think, is heavier than the bacteria. So, they’re counting on basically separating the fat using centrifugation and then running the rest of the milk through a filter that captures a lot of the bacteria—not all of it, they make that very clear in this patent. It’s like, “It does not remove all the bacteria.” It just lowers the bacteria concentration, and then they remix it back in with the fat. But, that’s the closest we’ve gotten to separating bacteria from milk, and the issue is because fat and bacteria are the same size. So, probably the only way… You know, anybody who invents this is going to be a very rich person, I think, but if someone can find a filter that separates bacteria from the fat of milk—probably based on surface properties is the only way I can think about it. Because, the surface of a bacteria is very different from the surface of fat. But, yeah…
Deborah Niemann 10:46
And one of the things that some listeners may have heard before is that, if you chill your milk quickly, it will taste better. And that’s true to a point, because bacteria is gonna grow much slower when it’s refrigerated. So, if you can get it chilled, you know, like, immediately—as soon as you bring it to the house—rather than, like, letting it sit on the counter for three or four hours before chilling it… The bacteria is gonna be multiplying crazy fast before it goes into the fridge. But I remember, even before we fully understood the importance of getting the udder clean—and we’re not talking crazy, or, we’re not talking about putting bleach on your goat udder or anything like that. Like, we just would clean it with a wet washcloth. But, before we knew that, I did notice I really did not like our milk beyond about three days; after about three days, it was going to the pigs or the chickens or somebody, because I didn’t think it tasted that good anymore. And it’s because the bacteria that was in there was continuing to grow. So, even though it wasn’t enough in the beginning to be so gross that it caused me to give it to the pigs right away, that after about three days, the bacteria had gotten high enough where I was like, “Yeah, this isn’t that great anymore.” And so, I wasn’t really that interested anymore.
Catherine Bailey 12:06
Yeah, because something that’s really important to point out about milk is that it is the perfect breeding ground for bacteria, because it is full of lactose, and bacteria love—and bacteria love sugar. I mean, that’s…
Deborah Niemann 12:20
Catherine Bailey 12:21
Yeah. So, what happens, actually, is that bacteria eat the sugar, and then they release acid. And so, that contributes to bad taste as well.
Deborah Niemann 12:28
Oh, that totally makes sense! I know exactly what you mean. I’ve tasted that! It does get slightly acidic.
Catherine Bailey 12:39
Yeah. What’s kind of funny—because like I said, I researched this. I went down that black hole when I was researching bacteria in milk. But apparently what happens is that, when you first milk an animal, there’s bacteria in there, and they’re going to feed off the lactose, and they release acid, and then it gets to a certain pH where that first kind of bacteria dies. But apparently, then another kind of bacteria can take over, because then it’s at the ideal pH. So bacteria, you know, they need to be at the right pH, they need to be at the right temperature, they need to have food. And so, obviously, if you keep it at room temperature, it’s gonna be at a better… Its bacteria are going to replicate a lot faster. But like you said, when you put it in the fridge, you don’t stop that replication. You don’t even stop that replication when it goes into freezer, technically. It just slows way, way down.
Deborah Niemann 13:24
Yeah. Wow, this is so fascinating. Is there anything else you want to say about the bacterial growth and how that affects taste and anything before we move on?
Catherine Bailey 13:34
Oh, no, that’s about all I have.
Deborah Niemann 13:35
Okay. The other thing I wanted to talk about—and this is funny, because this actually has to do with research I did. And I do mean legitimate research with CAD. This was with cows. About a year ago, I was hired as a contractor to help with some milking research with milking Devons, which is a heritage breed of cow. And,” when I got the first test results back, I was in shock. I was like, “There is no way that this is right. Because, it showed that the butterfat of these two cows was less than 1%. And I contacted the person who had the cows, and I’m like, “What did you do?” Like, I don’t… Like, this is impossible. There’s no way that—because her calves were being raised by their moms. So it’s like, “Your calves would have died.” If this milk was legitimately less than 1%, the calves would have died; they would not have survived. And I talked to the lab that was doing the testing, and what we ultimately figured out was this other issue—that we used to talk about all the time when you were on the farm, about… We’d complain about goats holding back their milk, but apparently, cows may hold back their milk, too. And, I’ve always heard people talk about this, like, the goats are doing it on purpose, the cows are doing it on purpose, because they’re nursing a baby, and they’re trying to save their milk for the baby, which kind of makes sense. But, as a former nursing mom myself, I’m thinking, “I couldn’t hold back my milk.” You know? I mean, there’s plenty of stories of nursing moms who are, like, in a store, and they hear a baby cry, and their milk just starts to flow. So, that didn’t 100% make sense to me, but it really, really felt like the goats were holding back their milk, right?
Deborah Niemann 15:31
Then, I also saw a study about goats that talked about how goats, when they are raising kids, and the kids are nursing, that the kids nursing causes an oxytocin release, which is the hormone that is responsible for the milk ejection reflex. And when we milk them, regardless of how much they love us, they don’t love us as much as they love their babies, and so we don’t get that oxytocin release. That’s what the research said. I think what we found was that, after a couple weeks of milking, or maybe a little longer, that we could get the goats to… We could finally get all the milk. And we never had any issues with our milk test; at least, I didn’t think we did. Now I want to go back and do research on my goats. But actually, somebody else did this already, where they took milk samples from different sections of the milking, like, from the very beginning of the milking, in the middle of the milking, at the end of the milking. And it indeed, when you put all this together… Goats and cows and humans, like… With humans, I remember we talked about hindmilk, meaning that the highest butterfat milk is gonna be at the back. So, the baby’s gonna nurse for a while before they get the really high-fat milk. And that is the same, apparently, with cows and goats—at least from the research that I’ve read and the research that I was able to do last year with the Devon cows. Like, massaging the udder more and things like that to try and get the goat to let down. Do you remember this?
Catherine Bailey 17:15
Oh, I definitely remember this. So, I remember… All the research you’re saying actually makes a lot of sense, because I remember first fresheners being the worst?
Deborah Niemann 17:24
Catherine Bailey 17:25
And then, the sooner after birth was definitely the worst. So basically, holding goats who were, like, months after they’d given birth, there was no issues with them holding back, but I definitely remember there was, like… I just remember their udders being so hard, and trying to massage them, and being like, “Come on, come on, let go,” you know? And there was some goats that would absolutely refuse to let up. And yeah, you would put them back in the pasture, and the babies would go in, and then if you felt their udder after that nursing, it felt soft, versus… Every now and then, massaging would work. There were definitely some goats where yeah, if you massaged it just the right way, you could even, like, you could definitely feel the udder, like, it would like to start to soften like they were definitely letting it go so that you could milk it.
Deborah Niemann 18:06
Yeah. And I think also, too—it was funny. One time, I remember we were doing a milk test. And it was… I think it was right after you had left home. And Dad was helping. He was just learning to milk, and it was milk test day, and we had done our morning milking. And Agnes gave me 3 pounds of milk in the morning—which I was ecstatic. I was like, “Oh my gosh, this is incredible! Oh my goodness, we’re looking at a 6-pound day; this is awesome. This is gonna be, like,” you know, “this is gonna be the second or third ever best milk test that we’ve had.” And then I got a migraine. And the thing is, too, so about that milking, is that I got half of that 3 pounds after I took the machine off of her. She was newly fresh. This was, like—she was a month fresh—when they have, you know, lots of milk. And she was not letting down for the machine. And so, I wound up having to get about half of that 3 pounds by hand after taking the machine off. And then I had a migraine in the evening, and my husband—who was still learning—tried to milk her, and for the evening milking he got like a pound and a half. So, her 24-hour total was only 4-1/2 pounds. Which was devastating to me, because, like, I knew if I could have been out there and milked her that I could have gotten more, but just simply because he was newer—and maybe because she didn’t know him as well, either—she was even more tense and less likely to let down her milk for him.
Catherine Bailey 19:48
Now, I wonder if having the kids nearby hinders that all, as well. Like, if they hear their… And, you know, you separate the kids overnight for milking and everything. If they hear their babies on the other side of the barn screaming, I wonder if that also keeps them from letting up?
Deborah Niemann 20:05
This interesting, because, like with women, remember I mentioned, like, you could be in a store when you’re lactating and, like, you hear a baby cry, and you’re like, “Oh my goodness, no,” because you can feel the milk start to let down. Because, one of the things that one lady was telling me with her cow—the way that she gets the high-fat milk from her cow—is by bringing in the calf and letting the calf start to nurse.
Catherine Bailey 20:30
Deborah Niemann 20:32
And then taking the calf away as soon as… She’s like, she milks until she’s like, “I can’t get another drop.” So, then she goes and gets the calf, brings the calf in, the calf start sucking, and you see at first that the calf is just like sucking, sucking, sucking, and then you see it start to swallow. And, as soon as she would see the calf swallowing, she’s like, “Okay, I know, the milk, let down now,” and she would take the calf away and then start to milk some more and get the high-fat milk.
Catherine Bailey 21:01
Deborah Niemann 21:05
So, it was really fascinating. I mean, like, the whole reason we did that study is just because, like, we wanted to know what the components were in Devon milk, and so we thought, “Oh, we’re gonna learn, like, what’s the butterfat, what’s the protein?” We also sent it to a special lab that was doing omega-3 and omega-6 and fatty acid research. It was a food scientist, which was pretty… Which was a lot more expensive than just your quick little dip thing. So, it was super fascinating, and I figured that you would also find this all interesting, too, since it just fit in so perfectly. It explains so much about our milking challenges years ago.
Catherine Bailey 21:51
Oh, it absolutely does. No, that’s great to hear. While we’re on the topic on science experiments, and kind of going back to the bacteria content in milk, I can’t help but to wonder if anybody has done an experiment regarding the bacteria contents in milk in different scenarios. You know, when you clean an udder, when you don’t clean an udder, between different goats, between different species even—like, I’m very curious to see if anybody’s done that study. And if they haven’t, I’m really curious if any listeners that happened to have a connection in the agricultural science community would be interested in running that experiment and sending me the results, because I’m actually really curious to see about bacteria contents in milk. And even, like, little things. Like, if you leave it out on the counter for, like, an extra hour, like, what, how that’s gonna change the bacteria concentration.
Deborah Niemann 22:40
Oh, yeah, that actually sounds really interesting. That’s actually something that really anybody can do. Like, you just take the samples at different times, number them, and send them off to the lab.
Catherine Bailey 22:51
That’s true! Yeah. I don’t have any goats right now, so I can’t do it, but…
Deborah Niemann 22:55
Yes! That would be the caveat. Anyone with goats could do that.
Catherine Bailey 23:01
Yeah. But yeah, I’d be very curious to see those results, because I know especially—from day to day, I imagine it varies too. Because I imagine people have had this happen, where sometimes you bring the goat on to the milking stand, and you have no idea what they did in the pasture, but their rear end is just covered in feces. And that’s the day where you need to spend, like, five minutes cleaning the udder as opposed to just a simple wash. I’m curious about the bacteria continent that milk as well.
Deborah Niemann 23:28
Oh, my goodness. And that is actually when—like, when that happens, that is when you go, “Okay, you’re gonna be last today.”
Catherine Bailey 23:38
I definitely would consciously do that if I saw it there—if there was a goat that had an extra-dirty udder.
Deborah Niemann 23:47
Yeah, you just put them aside and say, “Okay, you’re gonna be last, because it’s just gonna be gross cleaning your udder.” And I remember that. It’s funny how your sense of smell has such good memory, because as you are talking about this, I can smell goat poop. And it’s been a long time since I’ve been in that situation, but it’s just not fun to be in that situation. Because even, like, once you think the udder is clean, and it looks clean, after you milk that goat and you smell your hands, you still smell poop.
Catherine Bailey 24:22
Oh, absolutely. I definitely remember that. Or yeah, you think you got it all and you see one tiny little piece that you missed fall into the bucket.
Deborah Niemann 24:30
Yeah, so absolutely that’s why that goat goes to the very end, because you know, like, your hands are gonna be contaminated. The bucket is gonna be contaminated. Everything is gonna be contaminated with feces after you milk her, so she needs to be last.
Catherine Bailey 24:49
Yes, let’s reiterate again that bacteria for the most part is good, but fecal bacteria are not.
Deborah Niemann 24:56
Right, yeah. So, don’t worry about the skin and the hair bacteria. Hair is gonna fall into your bucket. That’s why you use a filter, to filter it out. But yeah, I’m kind of excited now about the possibility of doing some research and seeing how bacteria grows in there.
Deborah Niemann 25:18
Well, this has been a really fun conversation! Hopefully, people find this helpful so that… Because I know it was just so heartbreaking to dump, you know, a day’s milking because it tasted nasty. Nothing against the pigs or the chickens, but we always wanted to use the milk ourselves for making cheese—and don’t think you can make cheese from nasty milk. If you have nasty milk, it is gonna make nasty cheese.
Catherine Bailey 25:45
Oh, absolutely. I definitely remember having some goat-y batches of chévre.
Deborah Niemann 25:50
Oh, yeah. In the early years, we made so many mistakes. And some of them did not taste good at all. And so, we can tell you that eating that kind of bacteria in your cheese doesn’t hurt you at all; it just tastes really ew, not good.
Deborah Niemann 26:16
This has been awesome! And, if we think of any other cool topics, I’ll call you again.
Catherine Bailey 26:24
Sounds good! I think that detecting bacteria in milk is the limit of my research that I did that pertained to goats. But, if you think of any other topics besides homeschooling and bacteria detection, I’ll be there.
Deborah Niemann 26:40
Yeah, exactly. If you are listening and you missed the conversation with Catherine about homeschooling on the farm with goats, that is in a previous episode, which I will link in the show notes for you. So, thanks again for joining me, Catherine!
Catherine Bailey 26:54
Yes. Thank you for having me!
Deborah Niemann 26:57
Bye for now!
Catherine Bailey 26:58
Bye for now.
Deborah Niemann 26:59
And that’s it for today’s show. If you haven’t already done so, be sure to hit the “subscribe” button so that you don’t miss any episodes. To see show notes, you can always visit ForTheLoveOfGoats.com, and you can follow us on Facebook at Facebook.com/LoveGoatsPodcast. See you again next time. Bye for now!