When Male Cattle Lactate...

There was a time, only several days ago, when I would have cast the above title into the same box as "if pigs could fly" or some other nonsensical absurdity.

But an article crossed my desk that grabbed my attention. More because of who had written it than the actual title, because I read the author a lot and she's no-nonsense.

As it turned out, the article in question was not written in jest. But it was about beef steers (castrated beef bulls) that were found to be lactating at slaughter.

Male cattle, similar to human males, have small nipples that vaguely resemble their female counterparts. And the breaking story is that about 20% of conventionally produced feedlot beef are producing milk—to the point where it can be expressed from the nipples similar to a lactating cow.

I’m relatively open-minded, but this was wildly far-fetched even to me. 

I raise cattle. A steer is a castrated male bovine. A steer does not get pregnant, nor does it have a calf—which is a prerequisite for female cattle to lactate. 

At first, I thought it must be a joke. But the author of the article had brought the receipts and was a source I know and trust. 

The subject has been officially studied (although only to a degree) at West Texas A&M University, along with researchers from Cargill Protein. In the study, 20,481 finished cattle originating from 33 feedlots were examined, out of which 6,078 were found to be lactating, all outside of pregnancy and calving.

Before delving into this further, a little cattle terminology might be helpful. A heifer is a female bovine that has never given birth. It’s strange for a heifer that has never had a calf to be lactating. But a steer is a castrated male bovine. A steer producing milk takes strange to another level.

The Texas A&M study showed that among native beef heifers, 28.77 percent were lactating. Among dairy-cross heifers, an astonishing 55.81 percent were lactating. Among native steers, 14.55 percent were lactating. Among dairy-cross steers, 19.66 percent were lactating.

I’m still having trouble comprehending these numbers. A few steers lactating could be dismissed. A one-off. A freak occurrence. But 15-20% demands attention.

I raise grassfed grass-finished beef and have for over 15 years. While our cattle are in many ways the same type of animal raised in feedlots, we don’t use hormonal implants. I have never seen a steer lactate. Neither have any of our heifers produced milk prior to calving.

Why do I mention implants? Because at least 90% of feedlots steers and heifers have hormonal implants applied between placement in the feedlot and slaughter. Hormonal implants are a simple device attached to the ear that slow-releases substances like estradiol, zeranol, and trenbolone acetate in order to manipulate endocrine pathways because doing so increases growth and improves feed efficiency.

Scientists have known since at least the early 1970’s that lactation can be induced in bovines outside of pregnancy via hormone manipulation. Using substances like estradiol and progesterone, researchers were able to hormonally induce dairy heifers to lactation without pregnancy and calving.

To be clear, inducing heifers to lactation is not achieved using the exact pathways used in beef to increase growth and feed efficiency. However, there is overlap in the compounds used in both situations. Estradiol (an estrogen enhancer), for example, is used in both situations.  

The study I cited earlier did not record whether or not the animals had implants, but we can be relatively sure some did, given the ubiquity of hormonal implants in feedlot beef.

The hypothesis given by the researchers was that excess body fat in beef animals can increase estrogen production and could contribute to galactorrhea—milk production unrelated to normal pregnancy and birth.

It’s not uncommon for research to have what I call no-go areas, which is to say there are certain factors that are essentially off-limits in order to obtain funding for the study, which is often funded by either the industry or by land-grant universities that are heavily subsidized by agricultural industry.

I don’t know if this was the case in this particular study or not, but Texas A&M is a land-grant school, and hormonal implants are considered the holy grail in the beef industry. To have a study portray them unfavorably would not be appreciated by the beef industry.

Do I think implants play a part? Yes, I do. But I don’t know—because it hasn’t been studied. And that’s the exasperating part of this whole discussion. Certain things, seemingly, are protected to the point where too much is on the line to allow an honest review. Knowing, perhaps, would upset the apple cart.

Maybe the researchers are right. Perhaps it’s all about body fat. But then again, maybe implants also play a role. Maybe it’s diet. Maybe it’s a combination of more than one of these factors.

Nevertheless, something in the biological environment is telling the mammary glands of castrated males to produce milk.

I want to know more.

Were steers lactating at anything approaching these rates in 1950? In 1970? In 1990? Were slaughterhouse workers seeing this for decades while nobody thought to count it? Or is this a modern phenomenon?

More, is it a bridge too far to ask what this means beyond cattle?

Human beings also live in a complicated endocrine environment, more so than ever. Endocrine disrupters are a rising concern, whether it’s chemicals in plastics, water, cosmetics, or food. We are exposed to multiple substances that potentially affect our hormonal systems. Meanwhile, in meat production, we intentionally manipulate animals’ endocrine systems to make them grow more efficiently.

Whatever is making these steers lactate has not been proven to instigate a particular health problem in humans. We don’t know that.

But if factors in the environment, diet, or management of our food animals is producing an endocrine effect dramatic enough to make castrated male beef animals’ lactate, we should know what that something is. We should also be concerned whether or not it has downstream consequences for the animal, the meat, or the people who eat it.

Maybe it doesn’t. But it’s concerning enough that we should find out.

Hormonal implants work. That’s why the industry uses them. They allow cattle to gain weight faster and convert feed more efficiently. The question of the day--especially regarding the modern food system—is: What are we willing to trade for efficiency?

Is it early pubescence in girls? A growing estrogen-related infertility crisis in men? How about increased risk for certain cancers or disturbances to the nervous system? These are all endocrine related issues that are widespread in our day.

I’m not saying lactating male cattle, hormonal implants, or anything else mentioned in this article are causing the human health problems I just mentioned. We don’t know that to be true. Most health-related matters are not caused by any single one contributor.

But thinking people tend to notice similar language. And no one can be blamed for connecting dots between hormone manipulation in food animals and endocrine problems among humans. We can all draw conclusions as whether or not we believe these things are connected. But unfortunately, for lack of actual scientific study, we can’t know for sure.

All we can do is notice common practices in certain sectors of agriculture and see that it causes very strange unintended consequences (such as lactating male cattle). And then we can wonder what the unintended consequences are when humans consume the resulting food coming from such a system.  And that’s The View from the Country.